Dielectric resonator antennas

Over the past 30 years, many interesting developments have been seen in the field of dielectric resonator antenna (DRA). Analytical and numerical models for different shapes of DRAs were established in the 1980s and 1990s to understand their radiation properties. A couple of excitation schemes have also been proposed so that the DRAs can be excited efficiently. With the rapid advancement of dielectrics and microfabrication technologies in recent years, the DRA can now be made very compact for applications in portable wireless communication and millimeter-wave systems. In the first part of this chapter, miniaturization techniques of the DRA are discussed. It is found that the DRA can be integrated with power dividers for designing the circularly polarized and differential DRAs. Use of ground miniaturization technique has enabled realization of the omnidirectional CP DRA and the quasi-isotropic DRA for the first time. A review of the recent achievements in millimeter-wave DRA is then given. In this chapter, different dielectrics such as polymer and glass are also explored for designing the DRA. Transmission lines such as microstrip and substrate-integrated waveguide are deployed for exciting the DRA in the millimeter-wave spectrum. Elucidation is made on the design procedures and other considerations of the miniature and millimeter-wave DRAs.