Mode Analysis of Dielectric Resonator Antenna Based on Multipole Moment Expansion Theory

The mode analysis is of great significance for the dielectric resonator antenna (DRA). Different methods have been used to analyze DRA modes. Despite the progress, the accurate mode analysis of an arbitrary DRA remains a challenge. In this communication, the multipole moment expansion (MME) method is used to analyze DRAs with the help of COMSOL Multiphysics. According to the hybrid MME method, the scattered field of a radiator can be represented as the contributions of different multipole moments. It is well known that the DRA mode can be equivalent to an electric or magnetic multipole. Therefore, the peaks of the contributions of polar moments correspond to different DRA modes, giving resonant frequency of the modes. As compared with the existing methods, the hybrid MME method can accurately analyze the resonant frequency of the modes of an arbitrary DRA. For demonstration, several DRA designs are simulated with COMSOL Multiphysics and ANSYS HFSS. The results confirm the effectiveness of the hybrid MME method.