A Simple Solution for High Performance, Cost-Effective Filtering: A New Technique Widens the Tuning Range of TM-mode Dielectric Resonator Filters

A duly shaped Dielectric Resonators widens the tuning range of TM-mode Dielectric Resonator filters and allows a really cost-effective and high-Q radio frequency filtering operation. A method for a fast evaluation of the shaped-Dielectric Resonator resonant frequency and for the related filter design was investigated. The first realization has been for a Medium Capacity Digital Radio equipment in the 7 GHz band; it proved the correctness of our evaluations, having easiness of realization and tuning, and very good (near to theoretical) electrical performance. We describe in the following the design procedure of these wide-range branching filters and we show the typical results in terms of tunability and frequency response.