Theoretical investigation of aperture-coupled rectangular dielectric resonator antenna

Characteristics of an aperture-coupled rectangular dielectric resonator are investigated theoretically. A model based on the modal expansion method and the spectral domain approach is developed. Numerical results for Q factors, radiation efficiency and radiation patterns are presented for various values of material and structural parameters of the resonator, and it is found that by suitable choice of these parameters high efficiency, wide bandwidth and broadside radiation patterns can be achieved for the TE(111)(y) mode. Effects of aperture dimensions, aperture displacement and open-stub length on input impedances are also discussed. Results for return losses and radiation patterns are compared with available measured data, showing reasonable agreement. The results presented should be useful for the design of this type of new antenna.