Three-Port Pattern- and Polarization-Diversity Rectangular Dielectric Resonator Antenna

In this communication, a compact three-port pattern- and polarization-diversity rectangular dielectric resonator antenna (DRA) is investigated. The antenna is designed based on three TE modes,TEˣδ 11mode, asymmetricTEʸ1δ 1mode, and the presented quasi-omnidirectional mode, symmetricalTEʸ1δ 1mode. The radiation mechanism of the presented symmetricalTEʸ1δ 1mode is revealed by the theory of array and the geometric theory of diffraction. The asymmetric and symmetricalTEʸ1δ 1modes are supported by different boundary conditions. Based on the field-distribution difference between the two modes, an artificial boundary made of metal strips is electroplated on a portion of the side of the DRA to excite the symmetric and asymmetricTEʸ1δ 1modes simultaneously. For verification, a three-mode diversity DRA^^^is designed at 5.8 GHz. TheTEˣδ 11, asymmetric, and symmetricTEʸ1δ 1modes are excited by differential probes, slot in the center, and slots at the periphery, respectively. The overlapping 10-dB bandwidth of the three ports covers from 5.7 to 5.9 GHz. The envelope correlation coefficients and mean effective gain ratios are lower than 0.13 and 1.5 dB, respectively.