Tunable Compact Dielectric Resonator Filters

This paper presents a compact tunable dielectric resonator bandpass filter tuned by piezoelectric transducer actuators. The 4-pole tunable dielectric resonator filter is designed, fabricated and tested. It operates at 5.2 GHz with a 1% relative bandwidth. The filter consists of dielectric resonators made from high-K substrate placed in contact with the cavity wall to reduce the filter size. The tuning perturbs are located outside of the resonator cavity causing a minimum impact on the resonator unloaded Q. The filter is compact in size, yet it offers the potential of achieving a relatively high Q value close to 2000 over the tuning.