Dielectric Resonator Antenna with Y3Al5O12 Transparent Dielectric Ceramics for 5G Millimeter‐Wave Applications

Microwave dielectric ceramics are considered to be one of the key materials for dielectric resonators (DR) and have very broad application prospects in the fifth generation (5G) mobile communication system. Here we have prepared high-quality factor Y3Al5O12 (YAG) transparent dielectric ceramics using high-purity alpha-Al2O3 and Y2O3 powders by cold isostatic pressing of the vacuum sintered with tungsten meshes as the heating elements. Optimum relative permittivity (epsilon r) similar to 10.53, quality factor Q x f (Q = 1/dielectric loss, f = resonant frequency) similar to 95, 270 GHz (at =7.37 GHz), and temperature coefficient of resonant frequency (TCF) similar to -51.7 ppm degrees C-1 were obtained at a sintering temperature of 1780 degrees C for 12 h. For the first time, YAG transparent ceramic dielectric resonator antenna (DRA) is designed as a dominant TE111y mode and a higher-order TE113y mode using the aperture coupling feeding configuration excitation. The proposed transparent dielectric ceramic DRA can provide a broad impedance bandwidth of 4.193 GHz (ranging from 21.90 to 26.09 GHz) for S-11 < -10 dB, radiation efficiency of 92.1%, and compact DR unit. The proposed DRA can be used potentially as a 5G millimeter (mm)-wave multiple-input-multiple-output (MIMO) antenna unit.