Session: WFA

T/R Module Panel Architecture and Associated Technology (IMS)


 Frank Sullivan, Raytheon Company


 Ruediger Quay, Fraunhofer Institute Applied Solid-State Physics


This Workshop will focus on the various technology aspects associated with the advancement of T/R Modules for phased array applications. These aspects include the architecture and associated technologies, the manufacturing issues, the required advanced packaging, reliability and life cycle cost. The Workshop will cover both microwave and millimeter wave applications. It will cover key technologies such as GaN and SiGe. One of the main drivers of this technology is the promise of lower cost to produce the product as well as lower life cycle cost. This means that maintainability and reparability play an important role. Phased arrays can have multimode and multifunction applications including radar (search and track), communications and counter measures. These applications present major challenges. Two key attributes required to meet the end goal of low overall cost depend on the array to have high reliability and maintainability. These in turn require high standards of the components that make up the system and efficient built in test methods. Eight excellent international speakers representing key players in the field have been selected and confirmed to assure high quality of discussion. The contributors represent industry, government and academia.
This technology has advanced considerably in the last decade and this workshop aims to highlight these advancements and prospects for critical areas and show what needs to be achieved going forward.




Development of a Silicon Based W-Band Phased Array for Rotary Wing Aircraft

H. Bruce Wallace; Strategic Technology Office, DARPA, Arlington, VA, United States

This talk will discuss a millimeter-wave defense application of SiGe-based phased arrays. The unique advantage of this technology is its ability to deliver large wafers with high yield and low-cost, coupled with acceptable RF performance such as NF and output power for 94 GHz applications. Also, the entire control circuitry can be integrated on the same chip using the SiGe BiCMOS process. System-level considerations will be described as the basis for understanding the suitability of the technology. Issues associated with integration of the SiGe beamformer into a phased array will also be described.




GaN MMICs for Wideband T/R Modules

Dr. Rüdiger Quay; Fraunhofer Institute Applied Solid-State Physics

The material system of GaN offers great opportunities for new wideband or multiband operation which are currently exploited in many ways based on the high gain BW product and the impedance advantages of the GaN system. This talk describes the development of GaN MMIC for wideband applications in the frequency range from 0 to 40 GHz with very high power levels which offers great opportunities for multifunctional integration. This includes thorough discussions of wideband power amplifiers, wideband switches, and wideband LNAs recently realized for wideband modules and the limits of the technology with respect to wideband power or function per chip. Examples of MMICs with very high bandwidth from 0..6 GHz, 6-18 GHz and to 40 GHz are given and the typical limitations of the chip design and related integration aspects are discussed.




Lowering Phased-Array Costs using Silicon Integration, Built-In-Self-Test and Multi-layer Organic Boards

Dr. Gabriel Rebeiz; University of California San Diego

The talk will present SiGe (and CMOS) chips and how they are being used to lower the cost of electronically-scanned phased arrays. Example arrays at X-band and K-band will be presented with 2-D scanning capabilities. Also, millimeter-wave phased arrays at 60-100 GHz benefit greatly from integration and arrays capable of +/-60 deg. scanning at 60 GHz and 80 GHz will be presented. The talk will conclude with built-in-self-test designs which allow for much lower testing costs, especially at mm-wave frequencies where packaging and testing dominates the cost of phased arrays.




RF front-end design and scalability considerations for W-band phased arrays

Dr. Bodhisatwa Sadhu; IBM T. J. Watson Research Center, Yorktown Heights, NY, United States

This presentation discusses the benefits and challenges associated with the design of scalable phased arrays at W-band frequencies. First, the potential impact of phased arrays with tens to hundreds of elements for communication links at W-band is analyzed. The challenges and trade-offs associated with multiple integration and scaling options for W-band phased arrays are discussed, with special consideration to packaging and antenna performance. Finally, a solution based on SiGe ICs and organic packaging for a 64-element dual-polarized 94GHz phased array is presented, along with measurement results for both, the individual T/R front-ends, and the full scaled array.




Advanced Architectures for Active Millimeter-Wave Arrays

Dr. Arne F. Jacob; Technische Universität Hamburg-Harburg, Hamburg, Germany

In this presentation we discuss different advanced architectures for mm-wave arrays together with the underlying innovative technological approaches.
The main focus is on applications in satellite communications at 20/30 GHz with an emphasis on the development of terminal antennas for mobile applications. SSPA-based frontends for multibeam satellite antennas are another aspect to be covered.
Antenna solutions for high-speed, short-range line-of-sight communication scenarios at W-band are addressed at last.




Advanced Technologies for cost-efficient T/R Modules

Dr. Patrick Schuh; Airbus Defence and Space

Active electronically steered array (AESA) antennas are increasingly being favoured over conventional mechanically scanned systems. T/R modules are key elements in these active phased array antennas. Today there are two main streams in the development of these modules. One is the further performance improvement, like bandwidth, RF output power, multi-function integration, the other is targeting size, weight and power and cost (SWaP-C).
Especially the development towards lower cost has gained importance in recent years.
The constrain aiming for cost and weight reduction is the trend towards higher integration. Higher integration both on MMIC level, like GaAs or even SiGe Core chips instead of single function GaAs MMICs, and also on module level, like new more compact module architectures are under investigation. Also the transition from the traditional hybrid technology, using bare dies, ceramic substrates and metal frames to realize hermeticity, towards surface mount components soldered on organic substrates has a big impact on the overall cost. This technology is the enabler for new fields of application for AESA antennas, like Satcom on the move, weather and security radars.




Advancing Semiconductor and Associated Packaging Solutions Supporting the Deployment of Phased Array Systems in a Diversifying Marketplace

Eli Reese; TriQuint

The use of phased array systems in an expanding range of commercial and defense systems in radar, communication, EW among other applications, requires advancement in performance, functionality, cost structure and manufacturing capability. Those advancements are enabled by improvements in semiconductor technology, functionality and associated packaging technology to effectively employ that capability in requisite physical environments and cost structure. This workshop section will introduce some of those technology improvements emerging in the industry today and examine potential for further extension in the future. Examples of phased array transmit/receive applications in both defense and commercial applications will be included.


WFA-8 Packaging Consideration in Next Generation Active Array Modules
Dr. Andrew Piloto; Kyocera America, United States

Emerging RF systems which incorporate active array antenna subsystems require major improvements in the microwave packaging technology used for the transmit/receive (T/R) modules. For these active arrays to be viable, T/R module designs need to be lower cost, lighter weight, and more producible while simultaneously meeting ever increasing and integrated RF and DC requirements. Presented herein are examples of a variety of modules, many of which have already been produced in the millions, for ground, airborne and space-based platforms.
Fabricated from conventional packaging and in some cases PWB materials, these T/R modules incorporate an ultra-miniature, surface brazed RF connector and 3D RF and DC routing as well as multi-channel devices that have been co-designed to enable cost effective designs. The result is a packaging technology that reduces life cycle cost and achieves improved performance from previous designs. Also discussed is the incorporation of mechanical features in the T/R module that ease the array assembly thereby reducing its cost and time of manufacture for the array subsystem.



Session: WFB

Recent advancements on millimeter-wave 3D heterogeneous and multilayer MCM integrations


 Dr. Kamal K. Samanta, Milmega/AMETEK Ltd, Ryde, England


 Prof. Maurizio Bozzi, University of Pavia, Italy


This workshop presents, in a coherent way, the latest advancements and novel achievements in millimeter-wave and sub-mmW wafer-level heterogeneously integration and multilayer multichip module (MCM) technologies for realizing high performance and compact RF-front ends. The new wafer-level heterogeneously integrated circuit combines III-V semiconductor with Si technology, which allows taking the advantage of the high-freq. performance of InP and high power and broadband performance of GaN while maintaining the unique capabilities of BiCMOS, such as maturity and complex digital functionalities at a low cost. Further, the current trends and the state-of-the-art developments in heterogeneously integrated circuits (up to 250 GHz) including integration of InP-HBT on Si BiCMOS, and integration of GaN-HEMT and InP-HBT on SiGe BiCMOS would be discussed. The advanced MCM approaches for mm-wave circuit and system integration will also be presented; this includes packaging issues and the use of multilayer technologies, like liquid crystals polymers (LCP), ceramic (LTCC), photoimageable thick-film, organic and IPD.




Advancing millimeter-wave capabilities through 3D heterogeneous integration

Dr Daniel S. Green; DARPA/MTO, Arlington, VA United States

RF modules are increasingly moving to higher frequencies in the mm-wave region thus presenting challenges to operate with acceptable linearity, power efficiency, size and weight, and overall system performance. In recent years, Si- and SiGe-based RF/mixed signal technologies have made remarkable progress by leveraging advanced technology nodes and integration density; however, compound semiconductor technologies still possess fundamental material property advantages particularly as the operating frequency moves into the mm-wave regime. Heterogeneous integration is a promising technology to leverage both the material properties of compound semiconductors and the integration density of Si- and SiGe-based technologies in a single SoC. DARPA has invested in a number of programs to advance the design and manufacturing of complete RF modules leveraging integrated III-V and advanced Si solutions. This talk will discuss the latest advances achieved by these programs.




InP-on-BiCMOS hetero-integration for 250 GHz circuits

Prof. Wolfgang Heinrich; Ferdinand-Braun-Institut (FBH) at Berlin, Germany

A heterointegration approach of InP-HBTs on BiCMOS is presented which is pursued in a collaboration between the two German Leibniz institutes FBH and IHP, targeting systems in the frequency range beyond 100 GHz. It combines the InP-HBT transferred-substrate process at FBH with the SiGe-BiCMOS one at IHP. In a first step, the BiCMOS and InP wafers are processed separately. Then, both wafers are bonded using BCB and the process is completed removing the InP substrate and realizing the last metallization layers and the interconnects. This approach allows to combine InP subcircuits with SiGe-BiCMOS ones, with broadband interconnects up to 300 GHz. Modules combining the benefits of both technologies can be fabricated on a single chip. Hetero-integrated sources consisting of oscillator, multiplier and PA stages have been demonstrated and will be presented along with further circuit blocks in the frequency range between 160 GHz and 250 GHz.




3D Stacking of Advanced Compound Semiconductors with Si CMOS

Dr. Miguel Urteaga; Teledyne Scientific, United States

Advances in 3DIC stacking are being extended to heterogeneous integration of compound semiconductor devices with Si CMOS. Key process innovations that are being developed at Teledyne under the DARPA DAHI program include: CMP processes on III-V interconnects and materials, heterogeneous integration utilizing Ziptronix direct bond interconnects (DBI), and fine dimension InP TSVs for 3D integration. Challenges in transferring these processes,that are common to Si platforms, to more nascent technologies will be discussed. Design kit integration and mm-wave design considerations will be presented with examples from the design of mm-wave beamformer elements.




Synthesizer Improvement using Heterogeneous Integration of Silicon, Indium Phosphide and Gallium Nitride Technologies

Dr.Tim R LaRocca; Northrop Grumman Aerospace Systems, United States

This presentation covers the circuit performance advantages, lessons learned and challenges of a millimeter-wave E-band (71-76GHz) synthesizer that intimately integrates multiple high-performance III-V semiconductor technologies with an advanced CMOS node. The circuits are integrated using Northrop Grumman Aerospace Systems' DAHI (Diverse Accessible Heterogeneous Integration) integration process that bonds the technologies using a proven and reliable metal-to-metal interconnect otherwise referred to as a heterogeneous interconnect (HIC). The micron scale HIC enables the synthesizer and other circuits to use the best performing transistor without causing excessive loss and phase delay. The E-band synthesizer is a dual-mode design with the core VCO (negative resistance generator) designed using InP HBT technology for extremely low 1/f noise coupled with GaN output buffer for maximum output voltage swing. The VCO is embedded within an 11 channel CMOS PLL for a true DAHI optimized synthesizer.


WFB-5 Recent trends in RF/mm-wave packaging and integration technologies
Prof. John Papapolymerou; GATech Atlanta, USA

This presentation will focus on recent RF/mm-wave System-on-Package technology trends. WE will present examples from multilayer organic packaging solutions from a X-band to 170 GHz, as well as examples from thin glass packaging solutions up to 60 GHz.

WFB-6 Advanced MCM Technology Enabling High Quality Components and Highly Integrated Cost-effective Front-End at Millimeter-wave and Beyond
Dr Kamal K Samanta; Milmega/AMETEK, Park Road, England

Multichip Module (MCM/SoP) is widely accepted as an excellent means for realizing millimeter wave (mmW) systems. However, using conventional thick-film, it is very difficult to achieve either fine conductor geometry to realize passives with high quality as well as high SRF, or trench-filled metal walls for a substrate integrated waveguide (SIW) with applications in high mmW frequencies. Whereas, recently developed advanced multilayer photoimageable thick-film (PI-TF) technology is very promising and can comfortably overcomes these shortfalls. The process is straightforward, cost-effective and yet achieves line/gap of 10/15μm and trench-filled via, enabling realization SIW components comfortably to 180 GHz and beyond.
This talk will present the recent important advancements and novel achievements in PI-TF multilayer technology, which have been producing many records in MCM/SoP technologies. This will cover a wide range of high Q and SRF lumped/passive components and circuits (including low loss SIW) up to 200 GHz with remarkably high performance and miniaturization ever reported in MCM technologies, including LTCC, LCP and Organic. Then will present mm-wave systems, realized using an innovative assembling technique, including demonstration of the first highly compact complete V-band receiver integrating MMICs with embedded SIW antenna and filters, L/C components, LPF and other passives on a single substrate.

WFB-7 High capability GaN MMIC approaches and cost-efficient MCM heterogenous integration of Gallium Nitride

Dr. Rüdiger Quay; Fabian Thome; Fraunhofer Institute of Applied Solid-State Physics (IAF), Freiburg, Germany

From an integration point of view mm-wave Gallium Nitride is a classical stand alone IC technology which justifies it is existence by very good performances for single or very few functions per chip, e.g. in PAs, switches and LNAs. The good performance also allows a reduction of the passive components. This is typically true based on the high power and good robustness per chip. In addition mm-wave GaN poses stringend requirement on the thermal dissipation as the high power capability is typically achieved with efficiencies of 30 % in the mm-wave leading to thermal requirements beyond those of low-cost Integration schemes. The paper discusses novel mm-wave MMICs of interest to be integrated with more advanced silicon and GaAs/InP mm-wave in approaches in MCMs which are in-line with the advancements of the higher integrated technologies.

WFB-8 Silicon and Ceramic Based Microwave and Millimeter Wave Integration

Dr. Tauno Vähä-Heikkilä; VTT Technical Research Centre of Finland, Espoo, Finland

Aim to higher level of integration is one of the key focuses in modern radio front-end module development from RF (radio frequency) to millimeter waves. Especially this trend is driven by consumer electronics products. Silicon and laminate based technologies are driving development efforts in RF applications below 6 GHz and the same trend can be seen also to be used up to millimeter wave applications up to 110 GHz. Trough substrate vias and fine pitch flip chip technologies are in key role to allow miniature 3D integration. In addition to these, Low Temperature Co-fired Ceramics (LTCC) technology is used especially in microwave and millimeter wave integration. It is stable module packaging and integration platform technology. It can also be used for hermetic packaging needed in aerospace and other demanding harsh environment applications. This presentation shows examples of silicon, laminate and ceramic modules as well as compares their properties both from performance and cost point of view.

WFB-9 Wafer-Level Ball Grid Array Packaging Technology for Embedded Millimeter-Wave Modules

Prof. Dietmar Kissinger, 1IHP, Frankfurt (Oder), Germany, 2TU Berlin, Berlin, Germany, 3FAU Erlangen-Nuremberg, Erlangen, Germany

This talk presents the system and component design of highly integrated transceivers for radar and communication applications. In this context, integrated multi-purpose transceivers have been designed and packaged in a wafer-level ball grid array (BGA) technology which allows for direct embedding of the antennas in the package redistribution layer. This technique allows a very compact and efficient frontend realization comprising all millimeter-wave components in an 8x8 mm2 package. For verification purposes the highly integrated transceiver frontends have been soldered on a standard low-cost FR4 substrate printed circuit board and a millimeter-wave demonstrator system has been set up.




Session: WFC

Non Linear RFID Systems, Characterization and Exploitations


Smail Tedjini, Grenoble-inp/LCIS, France


Nuno Borges Carvalho, Universidade de Aveiro, Aveiro, Portugal


Apostolos Georgiadis, Centre Tecnologic de Telecomunicacions de Catalunya (CTTC), Spain


The workshop will focus on the nonlinearity in RFID systems. Indeed, the RFID chip, due to its rectifying circuit that harvests the EM power and therefore ensures the proper fed of the chip, is essentially a nonlinear device that generates several harmonics of the fundamental frequency of communication (868MHz, 915MHz, 950MHz, according to geographic regulations). This nonlinear property is usually considered as a spurious effect that contributes to the degradation of the RFID communication performance and therefore not exploited. Some pioneering papers have been evaluating such nonlinear properties just for purpose of comparison between several RFID chips. However, only few have been done on the exploitation of these nonlinear properties confirmed by experimental results. One of the objectives of the workshop is to review the state of the art of nonlinear properties of RFID chips. The workshop will also consider the exploitation of nonlinear RFID effects in order to enlarge the field of applications of RFID in particular within the general context of Internet Of Things.




Nonlinear behavior and characteristics of RFID chips

Gianfranco Andia-Vera; Yvan Duroc; Smail Tedjini; Grenoble-inp/LCIS, France

In this paper, the generation of harmonics in RFID chips is discussed as well as some visions for the exploitation of these nonlinear effects in applications. Experimental characterization of several RFID chips is carried out and their nonlinear performance are compared in term of power density of harmonics. It is demonstrated that for most RFID chips the level of the third harmonics is quite significant and can be easily measured. These experimental results are compared to a theoretical analysis based on an electrical circuit model. In the second part of this communication we address some application based on the exploitation of nonlinear behavior, in particular generation of the third harmonic. All the discussed applications require the design of specific antenna for the RFID tags. The design procedure should exploit three non-linear phenomena: (1) the impedance power dependency, (2) the harmonic production, and (3) the dependence on the RF waveform. The example of Electromagnetic Energy Harvesting from some usual ambient signals such as WIFI or UMTS is demonstrated and significant read-range improvement is observed in practice. The last part of the communication will discuss some new ideas extending the capabilities of RFID tags by exploiting their nonlinear behavior.




The use of NL generation for Passive TAG design

K. Nuno Borges Carvalho; Alírio Boaventura; Insituto de Telecomunicacoes, Universidade de Aveir

In this talk we will address the impact of nonlinear distortion on passive RFID TAG's, discussing the phenomena of nonlinear generation in the nonlinear front-end both from an implementation point of view, but also from a characterization point of view of nonlinear RFID TAG's. The talk will also address alternative solutions to maximize coverage range of RFID TAG's using nonlinear approaches when implementing multi-sine excitation.
Some practical examples on how to use commercial available readers combined with the proposed scheme will also be addressed and discussed throughout the presentation.




Energy harvesting and waveform selection for improved RFID performance  

Apostolos Georgiadis; Ana Collado; Centre Tecnologic de Telecomunicacions de Catalunya (CTTC)

The presentation begins with an overview and state-of-the-art in commonly used energy harvesting technologies such as solar, vibration, thermal and electromagnetic. Special focus is placed on challenges associated with electromagnetic energy transfer and harvesting for range maximization of passive RFID systems. Multiple technology harvesters leading to the development of energy harvesting assisted RFIDs are discussed. Low profile and conformal solar antennas and solar–electromagnetic harvesters including examples implemented on paper and textile substrates are presented. The integration of an antenna with a thermo electric generator is demonstrated. Waveform optimization in wireless power transfer is addressed, and the ability to improve the RF-DC power conversion efficiency of electromagnetic energy harvesting devices by tailoring the characteristics of the transmitted signals is discussed.



MIMO wireless power transfer for nonlinear energy harvesters and RFID transponders

Matt Reynolds; Daniel Arnitz; University of Washington, USA

This talk will present recent work toward enhancing far-field wireless power transfer (WPT) to nonlinear, passive UHF RFID backscatter transponders using a multi-input multi-output (MIMO) base station. The proposed method does not require on-tag power measurements or on-tag channel estimation, either of which would add prohibitive complexity and power consumption for microwatt-class wirelessly powered devices such as passive UHF RFID tags. We show in a measurement-based proof of concept that WPT optimization to nonlinear backscatter transponders is possible solely based on the backscatter signal, without knowledge of the incident power level at the tag or prior knowledge of the tag's characteristics. These results suggest that the use of MIMO interrogators could lead to improved forward-link performance and thus efficiently provide increased power for sensors or other new power-hungry functions on nonlinear passive transponders.


Multi-faceted Applications for Power-optimized waveforms/Multi-sines

Christopher R. Valenta; Matthew S. Trotter; Gregory D. Durgin; Electro-optical Systems Laboratory, Georgia Tech Research Institute, Georgia, USA

Power-optimized waveforms (POWs) and multi-sine excitations were originally designed to improve the energy conversion efficiency of wireless energy harvesting circuits. However, these types of waveforms can also be used for range estimation and 'charge tickling' in wireless sensor networks. This presentation will discuss the fundamental limits of energy harvester conversion efficiency and address how POWs are able to improve performance. These theoretical limits derived from closed-form equations are verified with simulated results and validated with laboratory measurements using a 5.8 GHz microwave energy harvester. These laboratory measurements demonstrate the most efficient, low-power microwave energy harvester ever reported in literature. Furthermore, the applicability of POWs for ranging finding applications and detection of un-powered passive tags will be presented. These findings show that tags can be localized to a distance corresponding to their POW RMS bandwidth and the estimation is further improved with a model for non-linear tag backscatter. Finally, a method known as 'charge tickling' shows that it is possible to detect the presence of a tag in an environment where it is unable to power-on.


Characterization of non-linear UHF RFID front-ends

Thomas Ussmueller; University of Innsbruck

This talk will highlight a comprehensive measurement-based characterization of an UHF RFID frontend at baseband and at RF. The presentation explains the necessity and the practical execution of the large-signal characterization and the nonlinear analyses of the frontend at UHF, including the effects of the power harvesting circuitry on the RF signal. The fundamentals of the source-pull measurement setup will be described in detail and the results of selected measurements will be presented.


Nonlinear Phenomenon in RFID

Ching Eng (Jason) Png, IHPC; Wai Siang Yeoh, A*STAR

The talk will mainly discuss about the non-linearity phenomenon in RFID and its possible utilization for future applications. The discussion focus on non-linearity issue in passive RFID system, which are related to (1) the input impedance variation when using COTS component for far-field wireless power transfer and (2) the spurious responses that may occur up to the 4th harmonic.
It is ideal for both the input of harvesting rectifier and the antenna to be precisely matched in an RFID device. However, owing to the non-linearity characteristic of the diode components, the impedance tends to vary with respect to input power. The variation mismatches the induced energy transfer from antenna to the rectifier and thus affects the efficiency. On top of that, the harmonic responses are very common in the RFID system due to non-linearity characteristic. The harmonic distorts the fundamental waveforms and affect the wireless channel.
In the talk we will discuss several common solutions from the industry such as harmonic rejection in order to increase quality of service (QoS). We will also propose possible method to utilize the "by-product" for certain purpose.


RF-baseband nonlinear co-design of zero-power harvesting systems

Alessandra Costanzo; Diego Masotti; DEI University of Bologna, Italy

In this presentation we discuss the entire nonlinear RF-base/band co-design procedure of RF rectifiers required to dynamically cooperate with ultra-low power management unit (PMU), which represent their actual loads. The design targets are battery-less RF energy harvesting applications with typical input power ranging from ~10 to ~100 mW. In order to allow activation in discharged states, the PMU is equipped with a low voltage start-up stage, specifically optimized for biasing the rectifier accordingly. When a sufficient voltage is reached, the PMU activates a more efficient boost converter stage with maximum power point tracking (MPPT) capabilities and micro-power consumption. These two configurations thus result in two very different loading conditions for the nonlinear operations of the rectifier. Thus to obtain successful operation, a joint design of the nonlinear rectifier paths and of the PMU sub-systems is mandatory, along with a circuit solution for automatically switching between the start-up stage and the boost converter. The design procedure will be extensively described and its steps demonstrated by means of a microstrip prototype and by a discrete components PMU. Finally possible different technology solutions will also be discussed.


Power-Integrity, Signal Integrity, EMC/EMI in Integrated Circuits and Systems for Wireless RF, mm-Wave and THz Applications

Sidina Wane; NXP-Semiconductors

Monolithic integration technology solutions open new perspectives for wireless Inter-Chip/Intra-Chip communications including applications such as RFID systems, reconfigurable sensors, contactless probing, and imaging/detection applications. The ultimate performance limits of wireless communication systems can only be achieved through a radical change of paradigm in existing system design and characterization methodologies. The required radical change calls for the definition of new design parameters and characterization standards based on 'Power-Energy' considerations for effective mitigation of three main performance limiting-factors, namely: actives (sources), passives (signal transports) and antennas (electromagnetic radiations). The handled signals being intrinsically multi-harmonic, impulsive and a-periodic, their analysis and characterization require distributed broadband Active-Passive-Antenna (Chip-Package-PCB) co-simulation and co-verification.
The proposed contribution will focus on Chip-Package-PCB electrical-thermal Co-Design, Co-Simulation and Experimental Co-verification for Power Integrity (PI), Signal Integrity (SI) and compliance with EMC/EMI requirements in integrated wireless communication systems. Practical near-field and far-field applications from RF, mm-Wave to THz domains will be discussed; perspectives for 'Power-Energy' aware design/characterization/verification together with the prerequisite unification of Analog and Digital domains will be drawn.

WFC-10 Chipless harmonic RFIDs on eco-friendly materials

Luca Roselli; University of Perugia, Italy

The novel application field of Internet of Things (IoT) is opening the door to the diffusion of wireless, energetically autonomous, sensor nodes embedded in any object. In order to fully exploit the possibility of having connected "things", communicating data one to each other and, in general, uploading sensed information on internet, some challenges have to be faced yet. One of these is related to the design of tags limiting or, possibly, eliminating the number of components (especially IC) on board in order to reduce the nodes' power consumption and the effect of pollution due to a huge amount of electronic devices deployed into the environment. A proposed solution is the adoption of harmonic chipless RFID tags which exploit the principle of signal frequency multiplication in order to separate the interrogation signal from the response of the tag itself and transmit 2 to 4 bits of information with no need of IC (just some passive components on board). During the presentation some examples will be described introducing tags that are not only chipless, but also manufactured by using biodegradable substrates (i.e. cellulose), thus improving their eco-compatibility and opening the door to the concept of "green RFIDs".




Session: WFD

Radar in a Communications-Driven Spectrum: Innovative System, Component, and Circuit Design for the Evolving Spectrum Environment


Charles Baylis, Baylor University, USA


Lawrence Cohen, U.S. Naval Research Laboratory, USA 


Robert J. Marks II, Baylor University, USA


Communications applications require significant bandwidth and also provide economic benefit through wireless device sales. Radar systems perform significant functions in weather detection, defense, and remote sensing. Radar systems will need to be designed to be spectrally sensitive and coexist with communications in dynamic spectrum access environments. This workshop has two parts: (1) discussion of spectrum challenges for radar systems and (2) investigation of cutting-edge solutions for radar design including designing to overcome amplifier nonlinearities, supply modulation for radar power amplifiers, , ambiguity-function design including spectral constraints, waveform design for radar with power amplifier distortion joint circuit and waveform optimization for reconfigurable adaptive radar power amplifiers, and tunable circuitry innovations to facilitate reconfigurable power amplifiers. The workshop will conclude with a panel session that will feature additional interaction between the speakers and attendees, and will be able to allow attendees to interact with speakers on how their solutions fit the needs they identified at the beginning of the workshop. Attendees will leave with a better understanding of the design challenges facing radar operators and having participated in drawing a "road map" to the design of future radars that will successfully coexist with evolving communications systems.




"What are the Issues," Discussion

A discussion, facilitated by the workshop organizers, will allow attendees to describe issues and challenges they are facing in spectral coexistence of radar and communication systems.




Spectrum Regulations and Measurements

Frank Sanders; U.S. National Telecommunications and Information Administration (NTIA)

This presentation details how radars are regulated. The worldwide and United States governing approach for spectrum is overviewed, including description of the functions of the International Telecommunications Union (ITU), the Federal Communications Commission (FCC), and the National Telecommunications and Information Administration (NTIA). The Radar Spectrum Engineering Criteria (RSEC), implemented by the NTIA for regulating radar in the United States, is described. Spectral masks are used to determine compliance with regulations, and construction of the spectral mask is explained. Measurement procedures for assessing compliance with regulations are surveyed. Finally, recent activities at the ITU related to radar regulation are presented.




Radar Issues in Spectrum Compatibility

Lawrence S. Cohen; U.S. Naval Research Laboratory

This presentation will discuss radar spectrum compatibility from three central themes: (1) system design impact due to regulatory and economic changes; (2) potential conflicts with wireless systems; and (3) radar phenomenology with emphasis on legacy and future receiver and transmitter design. First, radar emissions, as well as increasingly stringent design demands that are driven as much by economics as technology, will be addressed with respect to international and US regulatory criteria. Next, examples of radar emissions data that can cause interference with other systems will be presented and the presentation will discuss contemporary wireless systems in the context of their vulnerability to radar emissions. Finally, there will be discussion on the design of radar receivers and transmitters, both solid state and tube. Increasing regulatory requirements with emphasis on lower out of band spectral emissions for the avoidance of adjacent band interference will require new approaches to transmitter design. At the same time, anticipated changes in spectrum allocations in terms of such issues as spectrum sharing, dynamic spectrum allocation, guard band width, etc., will require innovative design approaches for receivers.




Power Amplifier Architectures for Radar-Comms Coexistence

J. Stevenson Kenney; Georgia Institute of Technology

Digital pre-distortion (DPD) and crest factor reduction (CFR) (aka peak-to-average ratio – PAR reduction) are now standard in transmitters for 3G and 4G commercial cellular communications. These signal processing techniques have led to much improved power amplifier (PA) efficiency. System capacity has also been increased because of lower in-band interference (error vector magnitude – EVM) and out-of-band interference (adjacent channel leakage ratio – ACLR). The same techniques have been applied to waveforms used in military communications as well. However, radar-comms coexistence proposes new challenges for mitigating interference while maintaining high transmitter efficiency. Commercial cellular PAs generally operate between 5 and 8 dB back-off, depending on the waveform complexity and the capabilities of DPD and CFR, to achieve reasonable efficiency with minimal interference. In contrast, high-power radar systems are traditionally run saturated, or with very limited back-off (1-2 dB) to achieve highest efficiency. Little consideration has been given to their out-of-band emissions, which are known to pose considerable interference to commercial and military communication (Comms). Moreover, advanced systems are now considering combining radar with comms in the same system, which will necessarily increase the complexity, and likely the PAR of the waveform. This presentation will discuss alternative PA architectures and interference reduction techniques required for radar-comms coexistence, either as separate systems, or combined in one system.




Supply-Modulated GaN Transmitters for Radar Waveforms with Improved Spectral Confinement

Zoya Popovic; Andrew Zai; University of Colorado

Typical radar power amplifiers are biased in Class C because it is an efficient class of operation and the bias level turns of the transmitter between pulses. However, this non-linear class of operation limits the transmitter to rectangular pulses because of the fast rise and fall times inherent to class of operation. We motivate the use of a radar pulse waveform which has a Gaussian shaped envelope because it has a well-contained spectrum, unlike the rectangular pulse, and show techniques to improve the Gaussian shaped pulse in terms of signal-to-noise ratio and range resolution. Theory is presented which shows a supply-modulated power amplifier can efficiently transmit a Gaussian shaped pulse. Lastly, a simple resonant circuit is presented as the supply modulator. Simulations and measurements of are performed for resonant supply-modulated X-Band GaN MMIC PA. 




Ambiguity Functions and Spectral Constraints

Robert J. Marks II; Baylor University

The ambiguity function describes the precision with which a radar waveform can estimate the range and Doppler of a target. The history of the ambiguity function's development in World War II is presented, and theoretical development of the ambiguity function is detailed. Examples of ambiguity properties of certain waveforms are described. The effects of amplifier nonlinearities on the ambiguity function (the estimation capabilities of the radar) are described, and the need to create an approach for obtaining desired ambiguity function properties despite transmitter amplifier nonlinearities is motivated. Research results are presented on the optimization of radar waveforms based on ambiguity function properties and spectral mask constraints.




Transmitter-in-the-Loop Optimization of Waveform-Diverse Radar Emissions

Shannon Blunt; University of Kansas

Driven by the demands for better spectral containment and for enhanced performance and capabilities through waveform diversity, a polyphase-coded FM (PCFM) scheme has been developed that leverages continuous phase modulation (CPM) used in aeronautical telemetry, deep-space communications, and BluetoothTM. PCFM waveforms are amenable to high-power radar systems while permitting design via optimization of an underlying polyphase code, thus enabling transmitter distortion to be incorporated into the waveform design process instead of requiring the separate determination and implementation of transmitter predistortion. Further, because this structure provides a direct connection between the parameterized code values and the physical radar emission, alternative transmitter architectures such as LINC can be readily incorporated as well as additional design freedoms such as spatial modulation (MIMO) and polarization modulation. Both simulation and experimental measurements will be provided to demonstrate the efficacy of this parameterized emission scheme.




Joint Circuit and Waveform Optimization for Power Amplifiers in Adaptive, Spectrally Sensitive Future Radars

Charles Baylis; Baylor University

This presentation details the development of an approach to simultaneously optimize the power amplifier circuit and input waveform for the goals of desired ambiguity function properties (radar estimation), amplifier power efficiency, and spectral compliance. An overview of optimization approaches that maximize the power-added efficiency (PAE) while remaining within spectral constraints (determined either by the adjacent-channel power ratio or the spectral mask) is presented. The Smith Tube is introduced as an expanded design space for joint circuit and waveform optimization, and examples of simulation and measurement results simultaneously optimizing the waveform bandwidth and the power-amplifier load impedance are presented. The presentation concludes by describing a research path toward microwave design techniques for spectrally sensitive cognitive and adaptive radar that include reconfigurable microwave circuitry and optimizable waveforms.




Cavity-based MEMS Tuners for Reconfigurable Power Amplifiers

Dimitrios Peroulis; Purdue University

A conventionally-designed tunable power amplifier needs a tunable matching network at its output. This typically results in added complexity, loss, and decreased linearity. An attractive methodology to avoid such difficulties and substantially improve the overall system performance is to consider co-designing critical modules of the transceiver chain. In this talk we will focus on co-designing techniques for power amplifiers and cavity-based MEMS tuners. We will introduce design methods that avoid tunable matching networks and results in significant benefits in the overall efficiency and linearity. We will pay particular attention to high-power limitations resulting in non-linear behavior and bifurcation characteristics. Furthermore, we will explore microdischarges that may be caused by increased power levels particularly for micron-scale gaps. It will be shown that these phenomena are strong functions of frequency and pressure. Measured and simulated results will be presented for all discussed phenomena based on GaN amplifiers and high-Q loaded cavity tunable filters.



WFD-10 Panel Session: Attendees and Speakers

A panel session will allow discussion and interaction between speakers and attendees about a way forward in meeting the challenges of radar in the spectrum environment.




Session: WFE

Thermal Management of High Power Density Electronic Assemblies


 John Pierro; Telephonics, Farmingdale USA


 Frank Sullivan, Raytheon, Sudbury USA


System applications ranging from commercial wireless appliances to the most sophisticated active electronically steered arrays for multi-mode airborne intelligence, surveillance and reconnaissance (ISR) and fighter aircraft radars are demanding more and more functionality in ever smaller footprints, presenting ever greater challenges to the thermal management of the system. Wireless devices must continually make room for circuitry to support the latest emerging wireless standards, more CPU, more memory, without any changes to the size of the device. The trend toward "tile-based" printed circuit board (PCB) packaging in modern AESA's, which is essential to making active arrays affordable and practical, and the insertion of high power density GaN technology (approaching 10w/mm) in AESA are demanding packaging innovations to solve very difficult PA thermal management problems. Embedded microfluidic cooling, DARPA's "ICECool", graphene nanoribbon technology, synthetic diamond heat spreaders and high conductivity substrates are among the many options available to the thermal engineer but are they optimum and do they keep the system affordable?
The workshop will assemble experts from Europe and America who are working to find practical, relevant solutions to these challenges.




An Overview of Various Critical Thermal Management Issues for Microwave PCB's

John Coonrod; Rogers Corporation

Thermal management issues for todays' microwave printed circuit boards (PCB's) continue to increase in intricacy due to several factors. There are frequency dependencies, design relationships, and material properties which are complicated by the fact that microwave PCB applications nowadays are structurally more complex than earlier designs.
This presentation will focus on several areas which are critical aspects for microwave PCB thermal management. A quick outline follows:

  • - Basic heat flow theory as it relates to PCB structures
  • - Circuit material properties critical to thermal management
  • - Heat sink attachment to PCB and related electrical performance issues
  • - Various circuit design configurations, heat flow modeling and confirming thermal images

The discussion related to basic heat flow will give the heat flow formula as related to a simple physics model and then expanding the discussion to an appropriate model for PCB's. Following the overview of heat flow will be a concentration on several material properties which are critical to thermal management. Some material properties, such as thermal conductivity, are assumed to be critical however there are several other properties which can be equally important for certain thermal-electrical configurations. A discussion regarding heat sink attachment to PCB will include the previous topics and supplement with microwave electrical performance issues. When a heat sink and thermally and electrically conductive adhesive (TECA) is part of the ground return path, microwave electrical performance of the PCB can be altered and this will be illustrated. Finally, all previous topics will be practically demonstrated by way of several microwave PCB designs, with heat sink attached using TECA, thermal images of the circuits with power applied and heat flow calculations related to circuit thermal performance.




DARPA's Intrachip Enhanced Cooling Program (ICECool): Embedded Cooling for RF and Digital Electronics

Avram Bar-Cohen1; Joseph J. Maurer2; Avinash Kane2 and Kaiser Matin3; 1Defense Advanced Research Projects Agency, 2Booz Allen Hamilton, 3Systems Planning Corporation

The increased integration density of microelectronics, along with advances in compound semiconductors and heterogeneous integration, has exacerbated the thermal challenges facing RF and digital electronic system developers. This has led to the proliferation of "thermally-limited" systems whose performance fails to reach the inherent transistor and circuit technology capability due to inability to remove the heat. DARPA's Intrachip Enhanced Cooling (ICECool) program seeks to overcome these limitations by "embedding" microfluidic thermal management in the chip to directly cool the heat generation sites. The ICECool technology, as well as thermal/electrical/mechanical co-design tools and methodologies, is being applied to GaN MMICs and digital ICs, with the ultimate goal of achieving greater than 3x electronic performance through the application of an ICECool embedded cooling technique.




Approaches, Needs and Future Trends in Thermal Management of High Power RF Systems

David H Altman; Raytheon Corporation

Changes in RF system thermal management over the last 50 years have been largely driven by the transition from vacuum power tubes to GaAs and now GaN integrated circuits (ICs) as a means to amplify RF power. This talk will address approaches and needs for RF thermal management by providing historical perspectives, a review of the current state-of-the-art techniques, and discussion on areas of development to address current and future needs. This includes an overview of state-of-the-art thermal packaging solutions for today's high power applications, as well as technologies under development targeting thermally unlimited utilization of GaN. Lastly, we will address the implications of future trends towards higher frequency operation, increased levels of integration, and the emergence of 3D RF and mixed-signal electronics on future thermal management solutions.




Thermal Design Challenges of Tiled-Array E-Scan Antennas

Angus McLachlan; George Fisher; Graeme Morrison; Tony Kinghorn; Selex ES, Edinburgh, UK

Next generation Radars are presenting significant challenges: with both improved performance demands and lower cost & size are being mandated by customers. Such requirements often include radar modes featuring high RF transmit duty ratio -- causing knock-on changes in radar antenna architecture, transmit/receive (T/R) module design approach, the semiconductors used therein, and crucially, changes to both packaging and interconnection schemes. All of this has given rise to almost unsupportable thermal management challenges.
This paper will explore some potential approaches to the design of a 'next generation', low-cost, tiled antenna -- highlighting the thermal challenges involved. The steps taken to assess and manage the effects of heat dissipation, as compared with the otherwise consequential impact on antenna performance and reliability, will be discussed. Looking forward, the 'wish-list' of alternative thermal management technologies and techniques that may be adapted and adopted for tailored use in the specific context of future antenna designs, will also be discussed.




Two-Phase Cooling for High Power Density Electronics

Andy Johnston; Parker Hannifin Corporation, Washington USA

The continued increase in electronics power density is driving demand for improved cooling solutions. Two-phase cooling approaches, in which the liquid coolant vaporizes as part of the cooling process, have more potential to satisfy this demand than do air or traditional liquid cooling. Two-phase solutions are capable of cooling performance well beyond the limits of single phase cooling, and in addition acquire waste heat with reduced temperature variation of the target surfaces. These advantages are more pronounced at moderate to high heat fluxes. Two-phase systems use many of the same components found in traditional liquid cooling, but lower two phase flow requirements result in substantial SWaP reductions. Two-phase cooling implementations include a variety of heat acquisition methods, each with their own advantages. This presentation will describe the various solution paths, such as micro- channels and spray cooling, and highlight the benefits of each.




Session: WFF

RF Acoustic for Mobile Communication: Challenges and Modern Solutions


 Andreas Tag; Friedrich-Alexander-Universität Erlangen-Nürnberg


 Clemens Ruppel; TDK Corporation


The demand for higher data rates and higher data volume results in higher usage of the available frequency spectrum. This means that more discrete frequency bands are used in today's cell phones compared to the past. And this results in RF front-ends with higher complexity and more discrete filter functions, which are typically implemented as acoustic filters due to their high Q factors. To meet these requirements novel materials, processing technologies, design methods and packaging techniques for acoustic wave devices had to be introduced. To meet future needs further innovations are required. This workshop will discuss the recent advancements in leading-edge technologies and define the future requirements together with possible solutions. Especially, recent achievements in SAW and BAW filter, duplexer, multiplexer technologies and RF front-end architectures will be highlighted, emerging acoustic thin film packaging techniques, temperature compensated and tunable acoustic wave devices will be outlined, and finally novel design methodologies will be discussed.




Advanced Design and Architecture of Next Generation RF Modems and Front-ends

Dr. Gernot Hueber; NXP Semiconductors Austria

The growing demand for higher and higher data rates and data traffic volume have been the main driver for the evolution of 3GPP cellular standards, that allow to provide this performance to the user. To meet those demands, the UE will need to evolve in the future to support the different HSPA configurations required, such as: DC-HSDPA, DC-HSDPA operation together with dual-band or MIMO, DC-HSUPA, HSDPA with MIMO, and LTE with carrier aggregation.
In this presentation we will focus on the architectural challenges and system requirements to cover all those evolved UE configurations and what it will impose on the multi-radio transceivers and the front-ends.




A Snapshot in Time: The Future in Filters for Cell Phones

Dr. Rich Ruby; Avago Technologies, USA

The phenomenal growth in cell phones and the recent and rapid adaption of Smart Phones has been recognized by all. What has not been articulated is that underlying the growth in Smart Phones is a larger growth and demand for filters and duplexers in the Smart Phone. Due to the demand of LTE 4G (and the future adaption of 5G), the number of filters needed in these phones has exploded. The driving forces behind the current and future demand for more bands in a phone are more data and faster delivery of data. This has led to the introduction of new bands, the introduction of Carrier Aggregation (combining existing bands), MIMO, Diversity and other filter intensive solutions to address the demand for increased data rates. And, whereas many of the components 'Count' in a Smart phone remains constant (e.g. the screen), the number of filters has gone from less than 10 per phone in the early 2000 to 2006 time frame to greater than 60 today and moving towards 100+ in the future. This talk will explore where this demand will be coming from and what will drive the new and tougher specifications for future filters.




Innovative and well-established approaches for designing acoustic duplexers and multiplexers

Dr. Andreas Link; TriQuint Semiconductor, Germany

State-of-the-art mobile devices contain more than a dozen FDD acoustic duplexers and at least as many TDD, WLAN and Rx diversity single acoustic filters. Furthermore, carrier aggregation (CA) is driving additional requirements for new quad-, penta- and hexplexers that will be used in next generation mobile phones capable of LTE-Advanced. This session of the workshop is intended to provide an overview of recently developed design methodologies for acoustic single filters, duplexers and other multiplexers. We will take a look at a systematic and well-structured design approach including simple resonator models necessary for time-to-market filter development and the additional challenges associated with flip-chip technology. We will see that utilizing the "natural" impedance of acoustic filters leads to cutting-edge filter performance and serves as the best choice for PA co-design on RF modules. Finally, requirements for inter-band carrier aggregation will be discussed and appropriate, space-saving solutions will be presented.




New Generation of very low profile SAW, TC SAW and BAW Devices for Module Integration

Dr. Karl C. Wagner; Dr. Tobias Krems; and Peter Hagn; TDK Corporation, Munich, Germany

The seemingly insatiable hunger for higher transmission rates drives the integration of more and more RF frequency bands in mobile phones' RF transceiver. Consequently, not only the optimum electrical performance of filters and duplexers for all known 3GPP bands but also the miniaturization of their outer dimensions must be addressed continuously. Lately a further reduction of component heights is of high interest for "slim" application designs.
A recently introduced packaging technology for micro-acoustic components called TFAP is addressing these needs. TFAP (Thin Film Acoustic Package) is a wafer level package realizing a cavity package required for SAW and BAW resonators. Maximum component heights of 0.17 millimeter without bumps (0.24 millimeter with bumps) with bump pitches down to 200 micrometer are achieved for standard SAW, temperature compensated SAW (TC-SAW) and SMR-based BAW filters and duplexers packaged in TFAP. Examples demonstrating also the latest status of chip technologies will be given.




Micro acoustic and MEMS device behavioral models in heterogeneous RF system design

Prof. Georg Fischer1; Klemens Brückner2; 1Friedrich-Alexander-Universität Erlangen-Nürnberg, 2Technische Universität Ilmenau

Micro acoustic and micro-electromechanical system (MEMS) devices bear great potential in addressing the demands of future radio frequency (RF) circuits, e.g., for mobile communications, in providing basic functions, such as oscillating, switching, amplifying, and controlling at high frequencies. For efficient system design and simulation of complex RF systems, behavioral system level models of the micro acoustic and MEMS devices have to be available. Thus, the focus on RF-MEMS is steered away from the technology and single-device optimization level to an application-oriented system level. The design of such systems combined from micro-electronic and micro-mechanic elements which demands novel design strategies and tailored circuit technologies referred to as "RF micromechatronics". The talk presents the utilization of behavioral models for bulk acoustic wave (BAW), piezoelectric MEMS resonators, and MEMS switches in the design of an exemplary LTE receiver architecture where common software tools for circuit design as Keysight Techologies Advanced Design System (ADS) and Cadence Virtuoso are employed for system simulation and optimization by directly influencing mechanical device design parameters. To realize this fundamental approach, a novel substrate technology that merges silicon and ceramic technologies into a novel compound substrate (SiCer) is introduced for the RF compatible simultaneous implementation and co-integration of micro-electronic and micro-mechanic devices based RF systems.




Tunable RF filters and trends in system architecture: A reality check

Dr. Robert Aigner; TriQuint Semiconductor, USA

The presentation reviews the leading trends in the RF front-end of smartphones. The perpetual challenge of multi-band/multi-standard solutions is to pack additional bands into the same footprint while also improving performance from one generation to the next. Are tunable filters THE answer? No, not anytime soon. Part 1 is a summary of realistic requirements for a 'hypothetical' tunable RF filter to cover multiple bands and thus displace both switches and regular filters/duplexers. Part 2 reviews the changes in system architecture required to address LTE Carrier Aggregation (CA). Multiple bands in simultaneous operation on a single antenna result in a large number of additional requirements for filters and duplexers. Isolation, loss and linearity are amongst the hardest to meet. With RF front-ends about to become more complex than ever, does this mean tunable filters are THE future? Maybe; it depends.




Tunable RF SAW/BAW Filters: What is Possible and What is NOT?

Ken-ya Hashimoto1; Tetsuya Kimura2; Takeshi Matsumura3; Hideki Hirano4; Michio Kadota4; Shuji Tanaka4; Masayoshi Esashi4,5; 1Graduate School of Engineering, Chiba University, Chiba Japan, 2Murata Manufacturing Co., Ltd., Kyoto, Japan, 3National Institute of Information and Communications Technology, Kanagawa, Japan, 4Graduate School of Engineering, Tohoku University, Miyagi, Japan, 5Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Miyagi, Japan

This talk is aimed at discussing possibilities of tunable radio frequency (RF) surface and bulk acoustic wave (SAW/BAW) filters with skillful use of micro-electromechanical system (MEMS) technologies. First, it is shown why RF tunable filters are demanded in current wireless communications, and various RF tunable filters are surveyed and compared. It is also discussed why such devices have not been widely
used. Then tunable RF SAW/BAW filters combing with the MEMS technologies are presented, and it is shown how high performances are expected provided that some key technologies are developed. Finally, a research project called "hetero-integration" conducted by the authors are introduced, and we show what become possible by combining MEM technologies with RF SAW/BAW technologies.




New Temperature Compensation / High Coupling Factor Materials for RF Acoustic Filters and Duplexers

Masanori Ueda; TAIYO YUDEN Co.

Temperate coefficient of frequency (TCF), coupling factor (K2) and quality factor (Q) are very key parameters on acoustic filters and duplexers. In this session, I will introduce our original two technologies on Lo-TCF and Hi-K2 which give devices big impact. Temperature compensated acoustic devices have been realized by improving temperature coefficient of velocity (TCV) or thermal expansion coefficient (TEC). We have proposed F-doped SiO2 material which improves TCV very effectively. We analyzed the material properties and demonstrated the effectiveness of it employing SAW devices. AlN is widely used in BAW devices as a piezoelectric material for mobile applications. The latest notable thing on material research proposed by some groups is Sc-doped with Hi-K2. We have been developing co-doped AlN theoretically and experimentally from another point of view, and we successfully have developed new materials (Mg-Zr or Mg-Hf-doped AN) with higher K2 than that of AlN.




Panel of all speakers

The panel is based on the speakers and the audience. Question sheets will be collected prior to the podium.




Session: WFG

Advances in Resonant and non-Resonant Power Combiners


 Giuseppe Macchiarella, Politecnico di Milano, Italy


 Aly E. Fathy, University of Tennesse


Power combiners are widely used in many microwave circuit applications. In particular, the recent evolution of communication systems has pushed the development of higher power, and more efficient devices that are suitable to operate with solid-state devices and up to millimeter wave frequencies. This workshop covers the latest progress in developing both resonant and non-resonant power combiners. In the latter class recent investigations have been concerned with splitters/combiners using various techniques like radial and conical combiners, and quasi-optical techniques. Other concerns include reduced circuitry size, ease and cost of fabrication like in SIW implementation).
Resonant combiners are traditionally constituted by filters suitably interconnected, whose task is to divide or recombine frequency channels (e.g. duplexers, triplexers, etc.). Lately, the modern communication systems call for additional tasks, making the design of these devices more and more complex and challenging. Examples of requested additional tasks are: multiband operation, reconfiguration capability, multiple manifold, matching requirements both in passbands and stopbands. In this workshop we present some promising design solutions adopted for realizing these new types of devices. Moreover, some practical implementations adopted (or being adopted) for resonant combiners in space and mobile communications systems of the latest generation are illustrated.




Direct synthesis of Diplexer-Multiplexer (40m.)

K.L. Wu; The Chinese University of Hong Kong

This presentation will introduce a direct approach to the synthesis of a diplexer or a multiplexer that consists of general Chebyshev band pass filters using an iterative approach. The approach is based on the concept of synthesizing a band pass filter with a frequency variant complex load. Having satisfied the three necessary conditions that stipulate the characteristic polynomials associated to the requirement of each channel filter, an optimal circuit model for each channel filter, together with either the length of the waveguide between a waveguide junction and the waveguide channel filter or a star-junction model for shunt LC resonator type of channel filters, can be generated iteratively and systematically. The approach will be taught in a simple technical language and illustrated with a large number of practical design examples, including waveguide type of diplexers, coaxial type of diplexers with a resonant type of junction and a triplexer with a non-resonant type of junction.




Manifold Multiplexer Design

M. Yu; ComDev Ltd, Cambridge, Canada (40m.)

The history of passive components for satellite payloads extends back many years with the invention of dual mode filters, switches, dielectric resonator filters and temperature compensated multiplexers. As a result payload architectures have evolved to the characteristics specific to these advances with ever increasing number of channels and some flexibility. The need for flexibility and mass/size reduction with ever increasing power demand is implicit for the rapidly emerging new satellite system. At same time, ground based wireless system also evolved to require more sophisticated multiplexer technology. This talk overviews some recent key component developments primarily in the areas of manifold multiplexers, addressing improvements in aspects such as flexibility, high power filtering, mass/size/insertion loss reduction. Some initial ideas for providing a level of flexibility to multi-beam payloads in the near term were identified with examples. These solutions are based on combining largely existing hardware with some new developments.




Combiners for base stations of mobile communications (40m.)

S. Tamiazzo1; G. Macchiarella2; 1Commscope, Italy, 2Politecnico di Milano, Italy

In recent years, requirement for antenna line devices to be used in base stations for mobile communication have undergone a twofold path: on one hand, selectivity and insertion loss requirement have become more and more stringent. On the other hand the complexity (in terms of number of filters and ports) of such devices has increased beyond the typical duplexer structure. This is caused by the increasing need for capacity in restricted spectral bandwidth and results in several cellular communication system sharing the same site including, where possible, feeder cables and antennas (this being driven by economic and environmental considerations as well). To cope with this, a number of new filter-based antenna line devices have emerged. Some of those devices will be discussed in this workshop.




Directional and miniature ceramic filters (25m.)

I. Hunter; The University of Leeds, West Yorkshire, UK

Recent advances in the design of highly selective directional filters and miniature ceramic bandpass filters used in combiner systems for mobile communications base stations will be described. This will include discussion of synthesis techniques and physical realizations.




Multiplexers for space application (40m.)

C. Ernst; TEC-ETM ESA/ESTEC, Noordwijk, The Netherland

Multiplexers are key components in today's communication satellites. In conventional payloads, Input Multiplexers and Output multiplexers tend to be of medium to large size with up to 20 channels. In modern Multibeam Ka-band satellites the number of multiplexed channels is smaller, but often in excess of 100 units are needed. Over the past years significant progress has been achieved to match increasing channel power levels and the demand for lower mass and smaller footprint. In this talk recent ESA supported developments are presented and significant achievements highlighted. Combined with the consideration of different payload architectures the will allow to derive future development needs of fixed frequency and reconfigurable multiplexer for space application.




Reconfigurable Multiplexers

A. Morini; Università Politecnica delle Marche, Italy

This talk discusses the implementation of tunable waveguide multiplexers. The target is represented by multiplexers with reconfigurable bandwidth and channel center frequency. Reconfiguration of each channel filter is realized by cascading a quasi-low pass block with a quasi-high pass block with variable center frequencies. For combining the channel filters the solution adopted allows to remove the degrading effect due to the reciprocal interactions of the filters. Some design examples illustrate the performance of the new reconfigurable configuration.




Recent Advances in Conical Transmission Line Power Combiners

D. De Villiers; University of Stellenbosch, Johannesburg, South Africa

AXIALLY symmetric N-way power combiners offer a number of advantages over conventional corporate and chain combiners when N is large. These advantages include higher combining efficiencies due to reduced insertion loss and improved amplitude and phase balance, as well as a reduced physical size and weight. With few exceptions, these types of combiners have traditionally been difficult to design, and normally a combination of electromagnetic field analysis and empirical techniques based on measurements are required. With the advent and continued improvement of 3D electromagnetic modeling software, the analyses and simplified design approaches of many variations based on radial, coaxial and conical transmission lines have been developed. This talk will discuss a basic background on axially symmetric combiners and the various types in use, as well as present the basic design techniques. An important issue, often misunderstood, with these reactive structures is the effect of higher order modes. The two main effects (isolation and bandwidth limitations) of these modes will by illustrated by full wave simulation models.




Quasi-Optical and circuit level power combining structures

A. Mortazawi1; R. York2; 1University of Michigan, Ann Arbor, USA, 2University of California, Santa Barbara, CA, USA

Output power of Solid-state devices decreases as their frequency of operation approaches the millimeter-wave region. Furthermore, most communications and radar systems require much more power than is available or expected from a single solid-state device. Conventional power combining techniques are not applicable at millimeter-wave frequencies due to their inherent losses. In this talk circuit level and spatial power combiners for the design of microwave and millimeter-wave power amplifiers will be presented. Circuit Level combiners based on The extended resonance and stacked devices will be discussed. Furthermore the design of spatial power combining amplifier arrays will be presented. These amplifiers are intended to replace Traveling Wave Tubes at Ka-band (26 GHz to 40 GHz) and W-band (75 GHz to 110 GHz). The highlight of our work is a 25W amplifier array at Ka-band developed through our collaboration with Lockheed/Martin Corp. Important issues such as uniform excitation and tolerance to multiple device failures will also be explored.




Combiners in Substrate-Integrated Waveguide Technology

J. Bornemann1; U. Rosemberg2; M. Salehi3; S. Amari4; 1University of Victoria, Victoria, BC, Canada, 2Mician Global Engineering GbR, Bremen, Germany, 3University of Waterloo, Waterloo, ON, Canada, 4Royal Military College of Canada, Kingston, ON, Canada

Multi-port power combiners are widely employed in modern communications systems in order to facilitate the combination of several high power signals, Butler matrices and beam forming networks within antenna subsystems. Substrate integrated waveguide (SIW) technology is a low-cost realization of traditional waveguide circuits that inherits the merits from both traditional microstrip technology for easy planar circuit integration and waveguide for low radiation loss and high quality factor. This presentation discusses the design and implementation of SIW combiners in various configurations. Starting from simple SIW divider networks, combiners as couplers with filtering capabilities are introduced. The main part is devoted to multi-port combiners with inherent bandpass filter characteristics. The design concept is introduced with respect to typical combiner performance expectations as well as the possibility of enhancing filtering characteristics within the combiner function. Performance comparisons between various full-wave field solvers as well as measurements of most combiner networks validate the combiner design procedures.




Waveguide Radial Combiners

G. M. Hegazi1; R. Kazemi2; A. Fathy31Aethercomm Inc., Carlsbad, CA, USA, 2University of Tabriz, Tabriz, Iran, 3University of Tennessee

The development of an X-band all waveguide radial power divider/combiner for high power applications is presented here. A TE10 mode in the input rectangular waveguide is efficiently converted into TE01 circular waveguide mode which is needed to in-phase feed the peripheral output waveguides ports. The mode transducer is composed of a power divider section and a mode converting section, which is connected to a 12-way radial power combiner section at the center. The mechanical structure of the mode converter feed, the choice of the matching post dimensions at the center of the radial, the radial line inner and outer diameter are the challenging tasks of this design. A prototype has been successfully fabricated and tested. Back-to-back transmission for both mode transducer and radial divide were measured as well. The achieved return loss of the full structure is better than 10 dB and the insertion loss is below 0.4 dB over the desired bandwidth of 10%.




SIW Splitters for low cost mm-wave antenna arrays

S. Safavi-Naeini 1 and Wael M. Abdel-Wahab1,2,3,  1Centre for Intelligent Antenna and Radio Systems (CIARS) , University of Waterloo, Waterloo, ON, Canada, 2C-COM Satellite Systems Inc., Ottawa, ON. , Canada, 3Electronic Research Institute (ERI) , Cairo,  Egypt

Substrate-integrated waveguide (SIW) technology has become a highly promising approach for the development of low cost circuits and components for a number of emerging microwave and millimeter-wave applications. More specifically, SIW splitter/combiners are proposed and being increasingly used as a feeding network for array antennas replacing traditional metallic feeding network. It significantly enhances the antenna overall radiation efficiency by reducing the feed network conductor loss. SIW structures are generally fabricated by using two rows of conducting vias in a dielectric substrate, connecting two parallel metal plates, and permitting the integration of rectangular waveguide components in planar form, along with printed circuitry (active devices and antennas). In this presentation, the SIW technology is reviewed and its application to microwave/millimeter-wave power combiners/splitters, with particular emphasis on low loss hybrid-feeding network for large array structures. The SIW splitters can also be integrated and hybridized with other types of planar lines and waveguides. A hybrid SIW/planar-line feed network for a high performance Ka-band satellite communication applications will be presented. The simulated and experimental results proves the usefulness of this technology and its scalability for large structures.



WFG-12 Theoretical Design and Realization of Variable-Impedance Microstrip Wilkinson and Bagley Power Dividers with Enhanced Electrical and Physical Features

Khair A. Alshamaileh1; Vijay K. Devabhaktuni1; and Nihad I. Dib2; 1University of Toledo, Toledo, OH, USA, 2Jordan Univ. of Science & Technology, Jordan.

The continuous advances in modern microwave subsystems, adjoined with the ever-growing demand on developing efficient and reliable front-end radios, are steering the torque of current research towards an uprising era of innovational applications, such as high data rate transmissions, through-the-wall imaging, and medical treatments. Similarly, a cognitive radio, which is considered as one of the promising communication schemes especially in enhancing access to the radio spectrum (EARS), takes a noticeable advantage of such a blast. The operation mechanism can be described by dedicating the temporarily unallocated frequencies to other secondary users as long as the "legitimate" users are in no need to transmit/receive data. Consequently, and in order to realize such a mechanism, cognitive radios crucially require front-end microwave components with customizable features for the sake of spectrum scanning with an intention of determining inactive frequency band(s). Power dividers, in general, are one of the key-components that reserve a clear importance in the progression of this arena. Recent investigations, thus, were redeployed in the direction of proposing splitters/combiners with advanced electrical characteristics (e.g., multi- and broad-band operation, unequal power division) and physical properties (e.g., reduced circuitry size, ease and cost of fabrication). Based on the abovementioned challenges, we propose different Wilkinson and Bagley power dividers with optimized electrical performance and compact easy-to-fabricate planar structures. Inspired by the concept of non-uniform transmission line (NTL) profiles, miniaturized multi-frequency and ultra-wideband (UWB) equal/unequal split power dividers are presented. Designs' verifications are established with the aid of analytical calculations and professional full-wave simulations. Further validations are performed through fabrications and measuring the scattering parameters of the proposed layouts.




Session: WFH

Wireless Power Transmission and Scavenging


 Amir Mortazawi, University of Michigan


 Jenshan Lin, University of Florida


Research and development in wireless power transmission and harvesting has grown rapidly over the past decade. Current commercial methods of wireless power transfer include near-field coupling for high power vehicle applications, lower power inductive charging, far-field power beaming and power harvesting to for embedded or hard to reach sensors. In this workshop the roadmap evolution for wireless power transmission and harvesting are presented. The transmission efficiency, transmission range and power handling capability are some of the key aspects of wireless power transmission systems that will be examined. The effective use and recycling of electromagnetic energy critical for operation of wireless energy harvesting devices and systems are also discussed. Other important issues that will be detailed include: electric vehicles charging, multiple devices charging, communication and controlling strategy for smart charging, EMC and human body protection regulations.




Wireless Power Transmission for Handsets

Kamil Grajski; QUALCOMM

This talk will provide a case study of how technical standards development within industry consortia is driving the transition of wireless power transfer technology from laboratory to market. The focus will be on wireless charging of portable consumer electronic devices. The talk will survey the active major industry consortia and global standards development organizations. We will discuss system reference models, magnetics and signalling requirements, interface specifications and organizing to meet the challenges of commercial certification and test. The talk will conclude by considering the applicability of the industry consortium approach to the multiplicity of wireless power transmission applications, such as energy harvesting, medical devices and electric vehicles.




Wireless Charging Technologies to Win Over the Consumer

Patrick S. Riehl; Mediatek, Massachusetts

Despite the relative maturity of the technology, wireless charging has not yet reached a tipping point of mass consumer adoption. In this workshop we will look at some candidate technologies that could shift the balance from being a novelty to a must-have feature. Multi-device chargers, multi-mode devices and wearable computing applications will be discussed, among others. We will work through some practical design examples at the circuit and system level to illustrate the challenges involved in enhancing the benefits of wireless charging for consumers.




Over-Moded Cavity for Scalable Simultaneous Wireless Charging of Multiple Electronic Devices

Zoya Popovic; University of Colorado, Boulder

Research and development in wireless powering devices has grown rapidly in popularity over the past decade. Current commercial methods of wireless power transfer include near-field coupling for high power vehicle applications, lower power inductive charging, far-field power beaming mostly for space applications, and far-field scavenging/harvesting to power embedded or hard to reach sensors that cannot easily have a battery changed. This talk discusses a shielded over-moded cavity for wirelessly powering multiple electronic devices simultaneously. As an example, a cavity approximately 7 by 10 by 16 free-space wavelengths is demonstrated for 10-GHz powering with a sub-watt transmitter. Methods to increase power density uniformity within the cavity are presented, including mechanical stirring, conductive and absorptive object loading, and frequency modulation. A statistical propagation model is developed for conductive and absorptive object loading to estimate power uniformity available in the cavity and the model is validated against measurements. The device-under-charge (DUT) consisting of a rectenna, microcontroller, power management circuit, solid-state battery, and ISM-band wireless transceiver is used to validate the study by monitoring the battery charging at various locations within the cavity. The demonstrated shielded three-dimensional charging method is scalable in frequency, volume, power, and number of devices that can be charged.




Circuit-level design of systems integrating wireless power transfer and sensors read-out

Alessandra Costanzo; Riccardo Trevisan; DEI University of Bologna, Italy

The great evolution of pervasive sensors technology has recently become attractive in industrial plants for monitoring several parameters in harsh environments. Indeed for industrial machinery applications, contactless sensor communication, combined with wireless inductive power transfer (WIPT), is seen as a great opportunity to optimize the productivity of the machine and reduce its maintenance. This is for example the case of power supplying rotary machineries with parameters of the remote branches to be monitored. RFID technology is a good candidate for solving this problem. In this talk we discuss an innovative design solution able to integrate LF contactless energy transfer and RF data transfer. We demonstrate the co-existence of high wireless power transfer and NFC communication for temperature sensor read-out. The nonlinear behavior of the RF-to-DC rectifier of a passive RFID is used for powering the sensor operations as well as for reading its activities, with no need for extra electronics at the RFID tag side to control the sensor readout.
System optimization and integration issues will be discussed and the operations of a prototype for 1 kW power transfer and for temperature monitoring is demonstrated.




Wireless Power Transmission: From Far-Field to Near-Field

Jenshan Lin; University of Florida, Gainesville, Florida

Recently, the interest in wireless power or wireless charging has been growing rapidly. Many researchers and engineers who used to work on different fields are now joining this topic. In the second talk, I will present an overview of wireless power transmission including far field microwave power transmission and near field magnetic coupling. The advantages and disadvantages of each will be discussed, and I will explain why the near field wireless power transfer is a better choice for charging consumer electronic devices and where/when the far-field microwave power transmission will be needed. A few examples demonstrated by my group, including wirelessly charging a laptop computer, will be shown.




Special Designed Waveforms for Wireless Power Transmission

Nuno Borges Carvalho; Institute of Telecommunications, University of Aveiro

In this talk we expect to discuss and explain how to design special signals to improve RF-DC conversion efficiency and DC voltage. In this approach the talk will be focus on multi-sine, and multi-carrier modulated waveforms for the improvement of RF-DC characteristics, a brief example will also be showed during the presentation.




Harvesting ambient RF energy with emerging rectifier technology
Simon Hemour; Ke Wu; Ecole Polytechnique de Montreal, Canada

After reviewing the potential sources from which originate the ambient energy, this talk will describe a selection of different rectifier diodes technologies, along with their evolution roadmap. The rectifier circuit architecture will be investigated for different scenario, toward the effective use and recycling of such an ambient electromagnetic energy. Metrics will be given to quickly evaluate the environment in which the application (e.g. IoT) is to be deployed. Some hybrid energy harvesting scheme will also be described, along with a discussion on the choice of the operating frequency.

WFH-8 Simultaneous Wireless Power Transfer and ZigBee Wireless Communication at Same Frequency Band
Naoki Shinohara; University of Kyoto

ZigBee sensor network, which requires low power only, is one of hopeful applications of a wireless power transfer (WPT) via radio waves. In order to reduce frequency cost, we propose a simultaneous WPT whose wireless power is intermittently transmitted during sleeping time of wireless communication of the ZigBee at same frequency band, 2.45GHz. The wireless power is synchronized with the wireless communication without any extra revise of the ZigBee wireless communication. We also developed a suitable rectenna, rectifying antenna, to drive the ZigBee sensor.

WFH-9 High Power and High Efficiency Wireless Power Transfer Technology for Automotive Applications
Joungho Kim; KAIST Korea

Wireless power transfer technologies can provide us a freedom from hardwired connectivity when using electrical powers for mobile platforms, home appliances, and automotive vehicles. Furthermore, we can reduce the cost of system power wirings, and will be able to reduce capacity and weight of batteries. Among the various wireless power transfer technologies, resonant magnetic field can offer not only the highest power transfer efficiency, but also the higher wireless transmission power in near field distance, especially suitable for automotive wireless power charging applications.

WFH-10 Ambient RF Power Harvesting for Low Power Sensors
Amir Mortazawi; University of Michigan

Wireless power harvesting (WPH) refers to the technologies that allow the radiated EM energy (from radio and TV stations, cell phone towers, etc.) to be collected for battery-less operation of various devices. Applications benefitting from WPH include structural health monitoring, large-terrain information gathering systems, Internet of Things, etc. In this talk, the design of efficient WPH systems based on detailed modeling of rectifying circuits operating at low RF power levels is discussed. Nonlinear properties of rectifiers around their threshold voltage are characterized and closed form equations for predicting the rectification efficiency, output power, and optimum matching network requirements are developed. Example of RF power harvesting circuits that can operate at very low power levels are presented.




Session: WFI

EM-Based Tuning Techniques, Computer-Aided Tuning and Tuning Space Mapping


 Qingsha S. Cheng, SUSTC, China


 John W. Bandler, Bandler Corporation, Canada


Fast pre-production and post-production tuning of complex microwave and RF filters is highly desired by the microwave industry. In this workshop we discuss three state-of-the-art tuning methodologies, EM-based simulator tuning (port tuning), computer-aided tuning, and tuning space mapping. Through explanation by experts, attendees will not only learn the techniques but also understand the fundamental commonality among the techniques—how existing knowledge and expertise are enhanced and updated in these processes. EM-based tuning techniques or port tuning techniques insert circuit elements into the tuning ports of an EM simulated device to achieve fast tuning. Computer-aided tuning automatically tunes a device with the help of a circuit-based model. Tuning space mapping uses a tuning model to aid the design of an EM simulated device. Circuit model extraction, calibration, and optimization algorithms may be used in each of the techniques. Comparisons are given among the techniques. Examples and tutorials of tuning (or design of) various filters are shown to illustrate the effectiveness of the techniques.




Industrial Applications for EM Optimization, Space Mapping and Tuning

Peter Thoma; CST AG, Germany

Designing electromagnetic components and systems for highly competitive markets requires cost efficient development processes. Simulation driven design techniques allow for an efficient virtual prototyping by reducing the need for expensive and time-consuming creation of physical test samples. Very often, simulation is used for verification and trouble-shooting at the very end of the design process. In addition, simulation in combination with computer based optimization strategies can also be applied in very early design stages in order to speed up the process to develop an optimal solution. This presentation will show for a number of examples how electromagnetic simulation can be applied at various stages of the design process. In this context, it will also be demonstrated how a variety of different optimization methods can be used and even combined together in order to deliver better designs in less time.




The Use of Filter Tuning Techniques in EM-Based Design of Filters

Raafat R. Mansour; University of Waterloo, Canada

Over the past years, several computer-aided tuning (CAT) techniques have been developed for refining the filter performance. Typically, the measured results obtained by the network analyzer are linked to a CAT algorithm to determine the next tuning step. The same concept can be potentially used in EM-based design of filters by replacing the network analyzer by an accurate EM simulator. In this case, the algorithm will guide the designer to the next step in the design. The process can be linked to a space mapping technique to yield an accurate and efficient approach for filter design. The talk will present various techniques for computer-aided tuning of filters that can be efficiently linked to EM simulators for filter design.




Fast Surrogate-Assisted Optimization and Fine-Tuning of Compact Microwave Structures

Slawomir Koziel; Reykjavik University, Iceland

In this talk, a methodology for low-cost simulation-driven design optimization and fine tuning of highly miniaturized microwave structures is discussed. The first stage of the design process involves fast concurrent optimization of geometrically dependent, but electromagnetically isolated cells of the decomposed structure of interest. The cross-coupling effects between the cells are taken into account in the second stage, where a surrogate-assisted fine-tuning procedure is executed. The tuning process is based on space-mapping-enhanced low-fidelity model of the entire structure. The latter is constructed by cascading local response surface approximations (RSAs) of the relevant building blocks. The technique is demonstrated through the design of two compact branch-line couplers (BLCs) with optimized designs obtained at the computational cost corresponding to a few EM simulations of the respective BLC. Comparison of numerical results with several surrogate-based design approaches as well as experimental verification of the final designs are also provided.




Robust Optimization Based Filter Design and EM Port Tuning

Dan Swanson and Bob Wenzel; SW Filter Design, USA

Every general purpose microwave circuit simulator offers the user several optimization methods. These general purpose optimizers do not take advantage of the unique response characteristics of a microwave filter. We will demonstrate a specialized filter optimization engine that runs on top of AWR Microwave Office®. This optimizer captures poles and zeroes in the passband of the filter and finds an exact equal ripple response. We can optimize any valid filter topology that can be described in Microwave Office. In addition, if we start with a Chebyshev prototype, we can "grow" cross-couplings into the filter network via optimization without doing any synthesis. The same optimization engine can also be used when we port tune an S-parameter file produced by an EM simulation of our actual filter geometry.




Tuning Space Mapping: The State of the Art

Qingsha S. Cheng; SUSTC, China

The electromagnetic-simulator-based tuning process for rapid microwave design combines electromagnetic accuracy with circuit-design speed. Our approach is based on the idea of "space mapping" and the electromagnetic port-tuning technique. In this presentation, we explain the art of microwave design optimization through "tuning space mapping" procedures. Tuning space mapping exploits tuning models as surrogates. We categorize these tuning models into four main types. We demonstrate the implementation of these types through a simple bandstop filter. We provide application examples corresponding to these types utilizing commercial simulation software. Our purpose is to help microwave engineers understand the tuning space mapping methodology and to inspire new implementations and applications.




A Brief History of Tuning: From Design Centering to Space Mapping

John W. Bandler; McMaster University/Bandler Corporation, Canada

CAD techniques for design centering and tolerance assignment—yield-driven design—can be traced back decades. The discipline was expanded to include statistical parameter variations and postproduction tunable parameters at the design stage. Benchmark theoretical contributions in the microwave arena included model uncertainties and mismatched terminations. Simultaneously, algorithms appeared for computer-aided alignment and tuning, particularly for filters and waveguide multiplexers, leading towards full automation of tuning processes at the postproduction stage. In the late 1980's, the Raytheon/Texas Instruments MIMIC program spurred significant relevant software development. The 1990's saw the emergence of space mapping technology that allows fast design optimizations of circuits with full-wave electromagnetic simulator accuracy. Later, tuning space mapping methodologies appeared. Like conventional tuning, space mapping approaches fully exploit the engineer's traditional intuition. This presentation will put these historical developments into a modern context.




High-power Filter Design Using Space Mapping Principles

Dieter Pelz; RFS, Australia

High-power tunable RF bandpass filters for broadcast application must fulfill very tight selectivity mask specifications over a relatively wide tuning range. Furthermore, the freedom of choosing topologies and filter degree usually does not exist and filter selectivity is exploited to a maximum. Sub-structures of high-power filters are not conveniently small compared to the wavelength, introducing a further design challenge. The design process must therefore be more accurate than what is typically required for fixed frequency, low-power filters. Frequency dependencies play a much bigger role here than usual. Coarse filter models with enhanced complexity are used in order to cater for the required higher accuracy. Relationships between Eigenmode solver models of filter sub-structures and the overall filter model are to be taken into account in a streamlined and fast converging design process. Areas of design accuracy enhancement will be shown and explained. Information on achievable design accuracy will be provided. Design examples will be presented.




Miniaturization and Optimization of Microstrip Filters using EM-based port Tuning Techniques

David Bates; DLI a division of Knowles Corp, USA.

Microstrip microwave filters are some of the more technically challenging cases for application of EM-based port tuning resulting from their Hi-Q resonant nature and close physical proximity of their elements. Both intended and un-intended couplings are present in most designs, which require EM analysis and optimization of the design. Optimization of designs is far faster using internal ports for tuning. Internal port de-embedding has advanced in accuracy levels and solution speed making this is a "must have" tool for filters, components and MMIC design. The port tuning technique will be demonstrated in the miniaturization of a microstrip filter, and modelled versus measured data presented.




Session: WFJ

Nanosecond Pulsed Electric Fields (nsPEF) – from modeling to applications: biology, medicine, plasma and apparatus


 Philippe Leveque, XLIM, CNRS-University of Limoges


 Delia Arnaud-Cormos, XLIM, CNRS-University of Limoges


Nanosecond pulsed electric fields (nsPEF) of megavolt-per-meter intensity are used in many promising plasma, environmental or biomedical applications. NsPEF have been shown to trigger functional changes in biological cells (e.g. Human cells), without permanent damage of the cell outer membrane. To investigate the physical mechanisms involved in pore initiation, molecular dynamics (MD) has emerged as a powerful numerical tool. To achieve nsPEF with MV/m field strength, appropriate exposure systems i.e. generators, delivery systems, measurement devices must be used, and constructing exposure systems for electropermeabilization with nsPEF remains challenging. Nanosecond repetitive pulsed plasma discharges (NRPD) are currently being explored as a mean of generating diffuse plasma. This workshop will cover state-of-the-art research on nsPEF from modeling to applications: biology, medicine, plasma, and apparatus. The workshop aims at opening new perspectives and promoting the involvement of the IMS MTT Community in the nsPEF research for biomedical and plasma applications.




nsPEF exposure systems for in vitro and in vivo bio-experiments

Francesca Apollonio; Sapienza University of Rome, Italy

To study of the effects of nanosecond pulsed electric fields (nsPEFs) action on biological samples, relevant for promising bio-medical treatments (e.g. cancer, neuronal-stimulation, inflammations, cicatrization processes), a controlled electromagnetic (EM) exposure is required, and hence suitable exposure setups to pursue reliable experimentation both in vitro and in vivo (laboratory animals) are mandatory. Biological experiments with short electric pulses have been studied for a long time and one of the most used exposure setups consisted in the so called electroporation cuvette for in vitro experiments, while planar or needles electrodes, for in vivo samples. Such structures, acting as a sort of capacitors, provide constant, non-propagative and high electric fields, which consequently polarize the bio-samples under analysis. Due to their intrinsic non-propagative nature, these setups resulted matched only up to few MHz producing large reflections and power losses when pulses shorter than 10 ns have to be used. In very recent bio-experiments where pulses of few nanosecond or even sub-nanoseconds started to be used and investigated, this item became evident. Moreover, looking at the growing interest in precisely understand the action mechanism of nsPEF down to single cell compartment (e.g. the plasma membrane), setups able to precisely expose even a single cell are strongly required.
To face the challenging issues concerning either the single cell exposure or the in vitro and in vivo experiments with nsPEF shorter than 10 ns, it seems interesting to consider the performances of classical propagating microwave structures (e.g. coplanar waveguide, microstriplines) or antennas (e.g. rectangular patches) matched on an extremely large frequency band (DC to few GHz). The functioning of such structures have to be verified and deeply characterized in order to respond to specific and stringent requirements as: broad band matching up to few GHz, high electric field amplitudes (up to MV/m) with good homogeneity within the exposed bio-sample volumes, contemporary exposure of multiple samples, simple modalities of sample positioning and monitoring (e.g. temperature, microscope imaging), suitable shielding.
The workshop will cover all the problematic issues regarding the design of nsPEF exposure setups, as well as the dosimetric aspects (i.e. Specific absorption rate calculation) related to the nsPEF exposures of the various bio-samples.




Generation and characterization of nsPEF for biological and plasma applications

Delia Arnaud-Cormos; Xlim, CNRS-University of Limoges, France

To achieve nanosecond pulsed electric fields (nsPEF) with MV/m field strength, appropriate exposure systems i.e. generators, delivery systems, measurement devices must be used. Generators that can produce powerful electrical pulses with adjustable duration, amplitude and shape are convenient but still unusual. Robust and versatile generators built on the frozen wave generator concept using photoconductive semiconductor switches will be presented. Bioelectromagnetic investigations are challenging because they are typically conducted in very small volume. They require the development of specific probes. This talk will concern measurements of high intensity nanosecond pulsed electric fields and temperature simultaneously measured using a unique electro-optic (EO) probe. A device for accurate electrical measurements for nanosecond repetitive pulsed discharges (NRPD) will also presented. The experimental setup developed is based on point-to-plane system integrated in a transverse electromagnetic (TEM) cell. For optimal energy transfer from the generator to the load, i.e. to the cells or tissues, special care must be taken to design devices compatible in terms of frequency bandwidth and impedance matching (typically 50 ohms). The talk will cover types of electrodes-based delivery systems for nsPEF applications.




Nanosecond transport through lipid bilayers and living cell membranes

P. Thomas Vernier; Frank Reidy Research Center for Bioelectrics, Old Dominion University, USA

He will report recent results from studies of the restructuring of biological membranes by nanosecond pulsed electric fields, and the transport of ions and small molecules through electropermeabilized lipid bilayers and cell membranes. In this context he will discuss ongoing efforts to reconcile molecular simulations with continuum models of electroporation and with data generated in vitro and in vivo, in order to produce a robust, physics-based, quantitatively predictive model of electropermeabilization.




Megawatts from Millijoules: A Discussion on the Science and Engineering of Nanosecond Pulsed Power Devices and Their Application for Research into Nonequilibrium Phenomena

Jason Sanders; Transient Plasma Systems, Inc., USA

The ability of high power transients to produce states of nonequilibrium in complex systems is fundamental to a number of research topics across a wide variety of disciplines. In many instances, the physical effects of these states become more interesting as the pulse duration and pulse spacing become comparable to or less than relaxation times intrinsic to the system under test, and, similarly, when the peak power is sufficiently high to meet or exceed threshold conditions. The capabilities of systems designed to produce megawatt pulses with nanosecond or picosecond rise-time and duration are advancing, thanks in part to recent breakthroughs in the commercialization of high performance power electronics devices. In addition to presenting results from experimental research powered by these devices, this talk will address science and engineering topics important to the development of pulsed power systems, focusing on high level system architecture concepts as well as challenges associated with transmission and metrology for high power, broadband pulses.




On progress of spectroscopic investigations of nanosecond pulsed discharges

Gabi-Daniel Stancu; Ecole Centrale Paris, Laboratoire EM2C, CNRS, France

The potential of atmospheric pressure nanosecond pulsed discharges for ignition and stabilization of combustion, flow control, biomedical applications, decontamination and material processing has been demonstrated in numerous studies. Here nanosecond repetitively pulsed discharges are generated in preheated nitrogen, air and air/methane flame environments. Investigations are carried out by optical emission spectroscopy and laser absorption and induced fluorescence techniques from UV to Mid-IR spectral domains. Insights of plasma kinetics, temperature and species production are presented.




Nanosecond Repetitive Pulsed Discharges (NRPD) in dielectric barrier discharge configuration

Francoise Massines; Promes, CNRS, University of Perpignan, France

In order to make antireflective and passivating coatings on silicon solar cells, a plasma reactor based on a dielectric barrier discharge has been developed with plane to plane configuration. The layer being SiN:H, the gas mixture is SiH4 and NH3 diluted in Ar to have the benefit of NH3 Penning ionization by Ar metastable.
At first the sinusoidal excitation frequency was fixed to sinusoidal low frequency excitation (50kHz) and a complete discharge study has been done in Ar/NH3 mixture showing that the discharge power is limited (3W/cm3) like growth rate. The power cannot be increased by voltage increase because of micro-discharges formation. As the energy per discharge is limited by the formation of microdischarges the best solution to increase the power must be to increase the frequency of excitation (>3MHz). Moreover, this solution should increase substrate temperature because of higher discharge power (36W/cm3).
Nanopulsed repetitive pulsed discharge (NRPD) allows to increase homogeneous discharge power until 17W/cm3 because impulsion time is shorter than microdischarge development. Moreover the short duty cycle (<1%) allow to prevent substrate heating while the growth rate can be similar to RF discharge for the same discharge power. Silicon nitride coating have been done in NRPD. Refractive index and surface passivation have been optimized for the application and show that we need to use less NH3 concentration to have the good thin film properties in comparison to sinusoidal excitation. The substrate is always cathode side where NH3+ flux is higher than sinusoidal excitation allow to reduce NH3/SiH4 ratio which control the refractive index. The coating is always homogeneous and dense but the substrate polarity are a great effect. In fact on anode side, powders appears and coating density and adhesion is lower than cathode side.
In conclusion, NRPD discharge allow to have a powerful discharge without substrate heating and growth rate similar to radiofrequency discharge. Silicon nitride layer have good properties for silicon solar cells.




Session: WFK

New Technology Developments for Space


 Nuno Borges Carvalho, IT-Universidade de Aveiro


 Steve Gao, University of Kent, UK


Rudy Emrick, Orbital Sciences


The use of microwaves in space applications is critical for the success of space missions. Microwaves are the base of earth-space communications, and in this sense satellite communications had become and will be the most reliable and low cost way for wireless communications for the masses. Recently the use of microwave signals to power up small space probes, or pico-satellites was also seen as a way to power up and allow better integration of those systems, with a huge cut in wires, and thus in weight.
In this workshop we will be addressing these different approaches to the use of microwaves in space and how those can become a reality in recent years. We will cover the use of GaN in the context of satellite systems, the design of millimeter-wave smart antennas for high-performance broadband mobile satellite communication systems, and the use of Software Defined Radio for Satellite transceivers in order to allow improved and more efficient satellite transponders and will address also the approach of electromagnetic energy harvesting and wireless power transmission to use in space environments.
It is expected that the audience understands the main novelties related to space communications in an integrated way and discusses future directions in this area




Market Trends and Key Technologies for Satellite Communications

Rudy Emrick; Orbital Sciences, USA

The growth in demand for broadband has been seen in satellite communications as it has in other aspects of the market. Satellites carry media content around the globe which includes satellite television, radio and broadband services directly to consumers. While the satellite industry is a relatively small percentage of the overall telecommunications industry, it's still a large market in terms of dollars. As in other areas of the telecommunications market, the market drivers have changed over time. Communications satellites are moving toward the realization of true high-throughput satellites (HTS), which can offer 2–20 times the total throughput of typical fixed satellite service that is offered today. The Internet protocol (IP) over satellite market is pushing this trend, and the move toward true HTS will allow the cost per megabyte to continue downward. In addition, there is also a great market potential for narrow-band machine-to-machine (MTM) applications as the costs in delivering data continue downward. These market changes and the ability to adapt to future market changes after a satellite is already in service have effected future satellite architectures and the key technologies needed to enable them. A detailed discussion of the key trends in markets, communication satellite architectures and enabling technologies will be given.




Millimeter-wave smart antennas for advanced satellite communications

Q. Luo; 1S. Gao; L. Zhang; D. Pham Minh; 1University of Kent, UK, 2Airbus, France

This talk will review some recent development worldwide in Ka-band smart antennas for satellite communications as well as show some results of case studies on this topic. First, it will give a review of recent development in Ka-band smart antennas for satellite communications. Then, two case studies will be presented, including one Ka-band fully integrated active phased array with wide-angle beam steering capabilities for satellite communications on the move, and one electronically beam-switching array-fed reflector antenna for advanced satellite communications. Design considerations of antenna elements and arrays in each of these case studies will be explained and discussed, and some results will be presented. A conclusion and future work will be given in the end.




Transmitters and SDR for SATCOM solutions

Nuno Carvalho; Pedro Cruz and Wonhoon Jang; Instituto de Telecomunicações, Universidade de Aveiro, Portugal

In this talk an overview of transmitter design for Satellite applications will be given, including software defined radio solutions that could be applied in space transceivers.
The system overview and solutions for high power transmitter design with controlled power beams with high efficiency solutions based on space power combination will be addressed stressing the main limitations of these solutions.




Potential space applications of two far-field and near-field WPT systems

Alessandra Costanzo; Diego Masotti; DEI University of Bologna, Italy

In this presentation we discuss in details WPT systems solutions for potential space applications exploiting both near-field and far-field techniques.
In particular a lightweight and low-power system, combining RF-ID and beam-forming technologies, is described in details able to selectively powering battery-less devices pervasively distributed in the ambient. This solution is presented as a feasible implementation of portable satellite environmental testing and monitoring, thus allowing sensors reading in locations difficult to access.
Subsequently a contactless system for high-power transfer (of the order of kW) is proposed as a reliable wireless transition in rotating joints, to get rid of wires, for both power transmission and data communication.
In both cases design issues and the adopted practical solutions are discussed based on a rigorous implementation of a circuit-level design of the entire system, combining nonlinear and electromagnetic simulation.




Recent developments and challenges in wireless power transfer and energy harvesting systems

Apostolos Georgiadis; Ana Collado, Centre Tecnologic de Telecomunicacions de Catalunya (CTTC), Barcelona, Spain

The presentation begins with an overview of energy harvesting technologies and discusses recent efforts integrating solar, thermal and electromagnetic energy harvesting modules. Challenges in combining with high efficiency different low power energy harvesting transducer outputs are addressed and examples are provided. Wireless power transfer systems are presented and the ability to improve the RF-DC power conversion efficiency of electromagnetic energy harvesting devices by tailoring the characteristics of the transmitted signals is discussed.




Microwave Energy Harvesting for Satellite Health Monitoring

A. Takacs1,2; H. Aubert1,3; S. Charlot1; S. Fredon4; D. Granena4; L. Despoisse5; H. Blondeaux5; 1CNRS, LAAS, Toulouse, France, 2Univ. de Toulouse, UPS, LAAS, Toulouse, France, 3Univ. de Toulouse, INP, LAAS, Toulouse, France, 4CNES (French Space Agency), Toulouse, France, 5Thales Alenia Space, Cannes, France

This presentation will address some recent advances concerning the energy harvesting of the spill-over losses of microwave antennas of broadcasting geostationary satellites. The targeted application concerns the development of autonomous (by energy harvesting) wireless sensor for structure health monitoring of satellite antenna panels.
First, the electromagnetic environment existing on satellite panels will be investigated. Then several rectennas/energy harvesters working on Ku and K band will be presented with a focus on the overall efficiency, compactness and bandwidth of these designs.




The roles of Gallium Nitride hybrids and MMICs for future satellite applications

Quay Rudiger and F. Thome; Fraunhofer Institute of Applied Solid-State Physics (IAF), Germany

This talk describes the ongoing use of GaN in satellite applications. With the increased availability of GaN hybrids and MMICs recently a larger number of space applications have been dedicated to make use of GaN in space. GaN MMICs around 20 GHz are very suitable for future active array downlink system, while especially Ka-band and E-band MMIC are becoming available for SATCOM.
The talk discusses especially new MMICs and MMIC aspects and progress on commercial space qualification.




GaN microwave and power electronic devices for space: Challenges and chances

Joachim Würfl, Oliver Hilt; Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenz-technik, Berlin, German

: This presentation first points out specific advantages and benefits of GaN based microwave and power electronic devices for space applications in comparison to other competitive semiconductor device technologies. For a successful implementation of GaN-based systems in space reliability and radiation hardness are indispensable prerequisites. Therefore an overview on the current understanding of GaN-based degradation mechanisms will be provided. In this connection drift and permanent degradation effects of microwave and power electronic GaN devices are intensively discussed and related to technological details of device epitaxy, processing and layout. These considerations will finally lead to guide lines on how to further improve GaN device reliability.