Abstract :
The authors present an overview of tunable microwave and millimeter-wave bandpass filters realized in different technologies. Some general design principles are described. Recent progress in the performance of various tunable filters is reported. The authors survey magnetically tunable filters (ferrimagnetic resonance filters, magnetostatic-wave filters, evanescent waveguide filters, E-plane printed circuit filters), electronically tunable filters, and mechanically tunable filters. The typical performance parameters are summarized. This comparison shown that none of these devices can simultaneously satisfy all requirements for perfect tunable filters. For microwave systems where multioctave tuning is essential, a YIG filter is an obvious choice. In systems where the requirement of high power handling capability combined with low insertion loss, predominates, mechanically tunable filters and magnetically tunable E-plane filters are recommended. If the tuning speed is a crucial requirement, varactor-tuned filters or E-plane filters with ferrite toroids are devices of choice. For millimeter-wave design, the most promising structures are ferrimagnetic resonance filters utilizing hexagonal ferrite resonators or, up to 60 GHz, magnetically tunable E-plane printed circuit filters
Keywords :
band-pass filters; magnetostatic wave devices; microwave filters; passive filters; resonators; reviews; tuning; varactors; waveguide components; 60 GHz; E-plane filters; EHF:SHF; MM-wave filters; MSW devices; YIG filter; band-pass filters; bandpass filters; design principles; electronically tunable filters; evanescent waveguide filters; ferrimagnetic resonance filters; ferrite toroids; hexagonal ferrite resonators; high power handling capability; low insertion loss; magnetically tunable filters; magnetostatic-wave filters; mechanically tunable filters; microwave filters; millimeter-wave; multioctave tuning; performance parameters; printed circuit filters; tuning speed; varactor-tuned filters; Band pass filters; Magnetic resonance; Magnetic separation; Magnetostatic waves; Microwave filters; Millimeter wave circuits; Millimeter wave technology; Resonator filters; Toroidal magnetic fields; Tunable circuits and devices;
