Workshops and Short Courses

This workshop focuses on recent advances and challenges associated to the realization of high performance reconfigurable microwave filters. This is an exciting and very challenging topic that is evolving from basic frequency tuneable structures to highly reconfigurable devices capable of keeping a competitive EM performance compared to their fixed counterparts. The first part of the workshop will focus on lumped-element, planar and substrate-integrated structures targeting moderate-to-high Qfactor in a very compact footprint. The second part will focus on recent realizations of high-Q 3D tuneable filters. Different tuning technologies will be covered during the workshop: from semiconductors to RF MEMS, liquid crystals or piezo-motors among others. Moreover critical issues like inband performance degradation, constant absolute bandwidth and type-of response control will be discussed. The workshop is promoted by the EuMA Topical Group on RF MEMS. Programme 9:00 09:10 Welcome 9:10 09:55 Micromachined transfer function adaptive filters Dimitros Perolis, Purdue University, USA  Abstract 9:55 10:40 MEMS, PCM and mechanical tunable filters Pierre Blondy and Stephane Bila, XLIM CNRS Université de Limoges, France  Abstract 10:40 11:20 Coffee Break 11:20 12:05 Compact tunable filters based on substrate integrated coaxial resonators Stefano Sirci, Technical University of Valencia, Spain  Abstract 12:05 12:50 Electronically tunable filters based on microwave liquid crystal technology Tobias Franke and Antonio Prasetiadi, Technische Universität Darmstadt, Darmstadt, Germany  Abstract 13:00 14:20 Lunch Break 14:20 15:05 Mm-wave and sub mm-wave MEMS reconfigurable waveguide components and systems Joachim Oberhammer, KTH Royal Institute of Technology, Sweden  Abstract 15:05 15:50 Reconfigurable waveguide filters for telecommunication systems Luca Pelliccia, RF Microtech, Italy  Abstract 16:00 16:30 Coffee Break 16:30 17:15 Tunable filters for wireless base stations Raafat Mansour, University of Waterloo, Canada  Abstract 17:15 18:00 Recent advances on high performance reconfigurable filters Ming Yu, COMDEV, Canada  Abstract 18:00 18:10 Open discussion and concluding remarks WORKSHOPS AND SHORT COURSES 9:10 09:55 Micromachined transfer function adaptive filters Dimitros Perolis, Purdue University, USA Abstract In this talk we will approach the problem of creating adaptive transfer function filters from two angles. First, we will review available and new technologies and second, we will present novel architectures for synthesizing the desired frequency responses. From the technology point of view, the frequency-tunable RF MEMS evanescent-mode cavity technology has been found to be a particularly promising solution. Not only resonators with this technology have shown promising characteristics in multiple areas, but also attractive technology solutions seem to be available to satisfy the remaining challenges. In addition, these resonators are fully scalable from sub-GHz to over 100 GHz while preserving their wide tuning range and low-loss characteristics. The second part of this talk will focus on architectural challenges. Approaches that are based on existing architectures with a mere replacement of static resonators with tunable ones have been proven rather ineffective. This is due to the fact that a fully adaptive response in this case requires not only tunable resonators, but also adaptive inter-resonator and external couplings. Adaptive couplings are quite challenging to implement and often result in significantly worse performance with respect to loss, selectivity, power handling, and linearity. On the other hand, new synthesis approaches that focus on cascading simple building blocks have shown very promising results. In this talk we will review such approaches primarily for interference mitigation applications. Tunable filters with the additional capability of changing their response from bandpass to bandstop will also be discussed. We will finally introduce the concept of Field-programmable Filter Arrays (FPFAs) and also review practical realizations along with their associated coupling matrices. 9:55 10:40 MEMS, PCM and mechanical tunable filters Pierre Blondy and Stephane Bila, XLIM CNRS Université de Limoges, France Abstract This presentation will cover the latest developments on tunable microwave filters using different technologies. Planar tunable filters with MEMS will be presented around 500-900 MHz, 2.4 GHz and 5 GHz. It will be shown that the filters shown very little loss and excellent linearity. PCM (Phase Change Materials) are an emerging technology that will permit the advent of multi-stable filters, that can preserve their operating frequency after the bias has been removed. The first results on this new technology will be presented at the workshop. The last part of the talk will present design strategies for cavity tunable filters with constant absolute bandwidth and rotating dielectric parts. The application of this technology to innovative satellite payloads will be presented. 11:20 12:05 Compact tunable filters based on substrate integrated coaxial resonators Stefano Sirci, Technical University of Valencia, Spain Abstract The presentation will be focused on the performances of analog and discrete reconfigurable filters based on Substrate Integrated Coaxial Resonators that have been developed in the last four years. Analog and digital tuning can be easily accommodated (even mixed) as well as different tuning elements depending on application: Ga As varactors for continuous tuning but reduced linearity, and PIN diode or RF MEMS for higher power handling but discrete tuning. The proposed structures present good EM performances showing moderate-high Q-factor with almost constant fractional bandwidth and good spurious-free response. This solution allows for miniaturized SMD self-packaged filters for low cost batch production, higher integration and easy assembly. 12:05 12:50 Electronically tunable filters based on microwave liquid crystal technology Tobias Franke and Antonio Prasetiadi, Technische Universität Darmstadt, Darmstadt, Germany Abstract Over the last decade, Liquid Crystals (LCs) have become increasingly promising as tunable dielectrics in the frequency range between 5 GHz and 1.5 THz, since LC losses generally decrease with increasing frequency. This contribution will present the operating principle of LCs, tuning mechanisms andbiasing schemes, filter concepts and design. Then, the outcome of a theoretical analysis, showing the maximal achievable performance of LC filters, will be compared with measured results for LC-tuned waveguide, SIW and planar filters. Finally, a summary will be given, discussing the advantages, but also the limitations of LCbased resonating filter structures, especially aiming for Ka-band satellite applications. 14:20 15:05 Mm-wave and sub mm-wave MEMS reconfigurable waveguide components and systems Joachim Oberhammer, KTH Royal Institute of Technology, Sweden Abstract This talk discusses a new class of MEMS-reconfigurable waveguide components based on MEMS-reconfigurable surfaces. Microwave MEMS waveguide switches and waveguide-switch based irises and filter demonstrators will be shown for 6090 GHz, with the MEMS chips assembled into standard WR12 metal waveguides. Furthermore, submillimeter-wave MEMS phase shifter circuits operating at 500600 GHz and based on up to 10 co-integrated THz MEMS devices, as well as (sub)THz MEMS WR1.5 waveguide switches will be shown. All designs are based on high-reliability, temperature-compensated, monocrystalline-silicon core all-metal SOI MEMS technology, eliminating the classical problems of surfacemicromachined RF MEMS devices, which is limited power/current handling, dielectric charging, long-term plastic deformation and operation temperature limitation, besides the frequency limitations of micromachined planar circuit technology. 15:05 15:50 Reconfigurable waveguide filters for telecommunication systems Luca Pelliccia, RF Microtech, Italy Abstract Tunable and reconfigurable bandpass filters and multiplexers with high unloaded Q, wide tuning range and low manufacturing cost are vital for the development of future tunable telecommunication systems minimizing the sizes of the frontends as required for both satellite and terrestrial applications. Efficient and reliable solutions for electronically tunable and reconfigurable bandpass filters could replace standard filter and filter banks enabling the realization of compact and flexible smart circuits. The presentation will address recent developments in high-Q waveguide filters tuned by electrostatic MEMS switches or by mechanical motors. Filters from LS up to E bands will be shown, demonstrating the great potentialities of reconfigurable filters in different applications and frequency bands. 16:30 17:15 Tunable filters for wireless base stations Raafat Mansour, University of Waterloo, Canada Abstract High performance tunable filters are needed in wireless base stations to facilitate efficient utilization of the available frequency spectrum. They can be employed to replace large filter banks in advanced systems concepts that self-adapt to environmental requirements. In addition, tunable filters can be used to consolidate more hardware into fewer units, which in turn will reduce basestation size and logistics management. The presentation will address recent developments in high-Q multi-function filtering devices tuned by piezomotors, WORKSHOPS AND SHORT COURSES MEMS, BST and semiconductor tuning elements. It also discusses techniques for adaptive and automated filter tuning. 17:15 18:00 Recent advances on high performance reconfigurable filters Ming Yu, COMDEV, Canada Abstract 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, but two fundamentally different characteristics of these new systems currently prevent similar hardware implementations being applied to these payloads. Specifically, the much larger bandwidths associated with broadband systems would cause on-board processors to consume considerably more power and dissipate extra heat while higher transmission frequencies lead to SSPAs with lower DC/RF power efficiency (PAE) thus similarly consuming additional power and dissipating extra heat.