Artificial circular dielectric resonator with resonant mode selectability

Resonant frequencies of natural circular dielectric resonator between its resonant modes has a close range each other, so some desired mode has to be chosen selectively from other modes. Therefore, a circular dielectric resonator with a capability to select the resonant mode is required. This can be overcome by artificially modifying some property of natural circular dielectric resonator, e.g. resonant mode, so that it has a unique characteristic. In this paper, some attempt to select the resonant mode of circular dielectric resonator is proposed by use of artificial circular dielectric resonator. The proposed artificial circular dielectric resonator is constructed of some open ring metal strips etched on a circular shape of dielectric substrate. The use of open ring metal strip aims to select the desired resonant mode of resonator. The effect of number of metal strips and its gaps as well as the effect of number of stacking dielectric substrate are used to evaluate the performance of proposed resonator in producing resonant frequency and inter-mode frequency separation. The investigation result shows that the resonator configuration consists of 1 strip with 4 gaps and of 2 strips with 4 gaps in different gap position has the lowest resonant frequency of TE_01δ mode.