14 GHz tunable filter based on waveguide-dielectric resonators

Abstract

Described are microwave four-pole waveguide filters electronically tuned by planar (Ba,Sr)TiO/sub 3/ film ferroelectric capacitors. The filters are tuned due to variation of ferroelectric capacitance with DC controlling voltage. Parameters of K/sub u/-band filters are the following: bandwidth for 1 dB level is /spl sim/0.8%, range of tuning is 260 MHz (/spl sim/1.8%); insertion losses are less than 3 dB.