Journal of the American Ceramic Society · 2021 · 75 citations · 39 references
EngineeringElectrical EngineeringMaterials ScienceAntennasCeramic MaterialsMicrowave EngineeringDielectric CeramicsDielectric MaterialsDielectricsMicrowave AntennasMicrowave ResonatorsSinteringCeramic DielectricsCold Isostatic PressingDielectric Resonator Antenna DesignDielectric Resonator AntennasDielectric ResonatorsPermittivityResonant FrequencyTransparent Ceramics
Abstract 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 Y 3 Al 5 O 12 (YAG) transparent dielectric ceramics using high‐purity α‐Al 2 O 3 and Y 2 O 3 powders by cold isostatic pressing of the vacuum sintered with tungsten meshes as the heating elements. Optimum relative permittivity ( ) ~10.53, quality factor Q × f (Q = 1/dielectric loss, f = resonant frequency) ~95, 270 GHz (at =7.37 GHz), and temperature coefficient of resonant frequency (TCF) ~ −51.7 ppm °C −1 were obtained at a sintering temperature of 1780°C for 12 h. For the first time, YAG transparent ceramic dielectric resonator antenna (DRA) is designed as a dominant mode and a higher‐order 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.
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