Realization of Cross-Coupled X- and Y-Shaped Dual-Mode Dielectric Resonator Filters

Abstract

Compact X- and Y-shaped dual-mode dielectric resonator filters of fourth and second order are presented, respectively. The dielectric rods are used in conventional $TM_{010^{-}}$ mode. Different resonator structures can be build up by suitable combination of the rods. The X-shape dielectric resonator filter consists of two cavities, where dual-mode operation is achieved by orthogonal arrangement of the dielectric rods. Due to suitable design of the coupling aperture two transmission zeros are generated permitting the realization of a quasi-elliptic response. The filter is manufactured and measurement results are compared with simulation. Furthermore, a Y-shape dielectric resonator filter is investigated. This filter provides the possibility of a further reduction of dielectric material, while still quasi-elliptic filter responses can be realized. The filter structure of both filter types is described and measurement results are presented.