Study of Broadband Dielectric Resonator Antennas

Abstract

This article briefly reviews broadband design techniques in dielectric resonator antennas (DRAs). The attentions focus on a type of DRAs that can offer multi-resonant frequencies and these frequencies can be mergered into a broad band. Index Terms - dielectric resonator antenna, broadband, multi-frequencies.1 I. Introduction Dielectric resonator antennas (DRAs) have attracted broad attentions in various applications due to their attractive features in terms of high radiation efficiency, light weight, small size and low profile [1]-[4]. Over last decades, various bandwidth enhancement techniques have been developed for DRAs. An overview on these techniques has also reported in [4], where these techniques were classified into three broad categories: Lowering the inherent Q -factor of the resonator; using external matching networks; and combine multiple dielectric resonators. In this article, recent broadband designs of dielectric resonator antennas (DRAs) are briefly reviewed. The attentions are focused on a type of DRAs that can offer multi- resonance frequencies and these frequencies can be mergered into a broad band. In order to effctively review design techniques, DRAs in this article are also categorized into three types, but unlike in [4], DRAs here are classed in terms of their components, such as a single DRA, multi-DRAs and a hybrid DR with other resonators, respectively. Especially for the hybrid resonator structures, they were not mentioned in [4] for they are newly developed. By using the present way, this article is expected to offer antenna designers more direct design choice and guidance. In order to achieve the above objective, this article first overviews several special features of DRAs showing their mechanism and potentials of multi-frequencies, and further broadband operation, and then a survey and a collection of several scattered papers are presented , and finally discussions and conclusions are given.