Application of Modal Polarization Current Model Method to Dielectric Resonator Antennas

摘要

The polarization current model method (PCMM), a volume integral equation method, has been used for the analysis of electromagnetic field scattering by a dielectric body and of radiation from a dielectric body. The authors have proposed the total domain method of moments, namely, the mode expansion polarization current model method (M-PCMM), in which the polarization current density is expanded in spherical wave functions, and have applied it to the analysis of dielectric body scattering. In the present paper, this M-PCMM is applied to the analysis of dielectric resonator antennas (DRAs) in which a rectangular dielectric body is excited by a wire probe. The results are compared with the measured data. They are also compared with those obtained by Ansoft's HFSS, in which the finite element method is used for analysis by an approximation using a dielectric waveguide model. The three methods of analysis provide sufficient results for the resonant frequencies and the unloaded Qs. In addition, the M-PCMM and HFSS provide results close to the measured values of the gain and the radiation efficiency. It is confirmed that a slight change of the spacing between the dielectric body and the external probe can affect the DRA characteristics significantly.