Dielectric Resonator Antenna - Possible Candidate for Adaptive Antenna Arrays

Future base stations for Spatial Division Multiplex Access (SDMA) will utilize adaptive antenna arrays, capable of identifying the direction of the incoming signal and steering the transmitted beam in appropriate directions. The radiating elements that have been thus far considered for building the antenna array are typically wire dipoles or microstrip patches. This tutorial paper describes a new type of radiating element, the dielectric-resonator (DR) antenna, that has some interesting characteristics, like the small size, high radiation efficiency and increased bandwidth. Historically, dielectric resonators have been used as circuit elements which enabled the miniaturization of microwave oscillators and filters, packaged in conducting boxes. Typical mode of operation in such shielded environment is TE01. In an open space, dielectric resonator acts as a radiator. Typical mode used for radiation is HEM11. The paper describes near field distributions, feeding mechanisms, radiation patterns and input impedance of DR antennas.