Dual-mode dual-band conductor-loaded dielectric resonator filters

A new class of dual-mode dual-band microwave filters is presented. Conductor-loaded dielectric resonators are used as a basic building blocks for these devices. The proposed resonator enables the realization of microwave filters with unloaded quality factors of 1000-4000 with good spurious performance and significant reduced size, e.g. less than the half physical size, compared to TEM filters. The basic properties of the proposed resonator have been studied and examined with the help of a finite element method solver (HFSS2015). A design example of a dual-mode dual-band bandpass filter with maximum transmission zeros for mobile communications is developed.