New concepts for dielectric multi-mode resonators with branches

In this paper new concepts for multi-mode resonators are presented, which are based on TM-mode operation in dielectric rods. By proper arrangement of dielectric rods in branch configuration, new fundamental eigenmode resonances could be shown to be present. In the simplest case, dual-mode operation could be achieved by an Y-shape arrangement. Higher number of fundamental modes could be obtained by adding further branches to the novel mono-block ceramic, which is suitable for planar fabrication. Furthermore, non-planar constructions are advantageously possible as shown exemplarily at a manufactured filter prototype.