Tunable Quad-Mode Dielectric Resonator Filter

摘要

This paper presents a quad-mode dielectric resonator filter enabling selective tuning of frequencies and couplings. The concept is based on two degenerated HEH-modes and two generated HEE-modes coupled in a single, metallic cavity. The set-up is described concerning resonator support, frequency tuning and coupling elements. Furthermore, three configurations of the coupling elements with different positions of the transmission zeros relative to the passband are shown. Finally, a prototype at 1820 MHz with a bandwidth of 20 MHz is presented. Simulation and measurement results indicate filter responses with narrow skirts and low insertion loss suitable for applications in cellular base stations.