TUNABLE FILTERS BASED ON DIELECTRIC RESONATORS Jerzy Krupka*, Adam Abramowicz*, Krzysztof Derzakowski*, and Robert N. Clarke#, SUMMARY The ‘TUF’ tuneable filters Framework 5 project was focused on the development and characterization of tuneable ceramic dielectric resonators, of tuneable filters based upon them and on cryogenic bolometry based on a coupled tuned resonator. Its objectives were conceived in the light of strategic developmental needs of the European Community. Contractors of the project were as follows: National Physical Laboratory (NPL), Ericsson Radio Access, Filtronics Comtek (FC), Josef Stefan Institute (JSI), Forshungszentrum Julich (FZJ), London South Bank University (LSBU), and Warsaw University of Technology (WUT). Several prototype resonators and tuned filters have been constructed by TUF partners based, respectively, on ferromagnetic, simulated-MEMs and piezoelectric tuning. The resonators and filters include the following: • • • • • • • •
Single-pole ferromagnetic axially tuned filter (WUT ) Single-pole ferromagnetic circumferentially tuned filter (WUT) Two-pole ferromagnetic axially tuned filter (WUT) Two-pole ferromagnetic circumferentially tuned filter (WUT) Single pole MEMs-tuned filter with 4 tuning slots (FZJ) Single-pole dielectric resonator filter with piezoelectric bimorph tuning (LSBU) Two-pole hybrid-mode dielectric resonator filter with piezoelectric bimorph tuning (LSBU) Four-pole hybrid-mode filter based on two dielectric resonators with piezoelectric bimorph tuning (LSBU)
All of these devices present significant steps forward in filter design and have provided important new practical information about the implementation of electronic tuning in high Q-factor filters. The three filters, in bold type in the above list, each employing a different tuning mechanism, and each developed in a different TUF partner’s laboratory, are the most advanced filters of each type that were comprehensively tested during the TUF project. Acknowledgments All of the partners in the TUF project gratefully acknowledge the support of the European Competitive and Sustainable Growth Research Programme through Grant GRD1-2001- 40547, EU Framework 5.
*
Instytut Mikroelektroniki i Optoelektroniki Politechniki Warszawskiej, Koszykowa 75, 00-662 Warsaw, Poland, email:
[email protected] # Centre for Electromagnetic Metrology, National Physical Laboratory Teddington, Middlesex,. TW11 0LW, U.K
