Design and fabrication of a millimeter-wave dielectric resonator antenna based on room-temperature densified NaCl ceramics

Low-temperature fabrication of dielectric ceramics with excellent millimeter-wave performance has attracted increasing interest for fifth-generation (5G) wireless communication systems. In this work, room-temperature densified NaCl ceramics were fabricated via a pressure-assisted process, and their potential as dielectric resonators for millimeter-wave antenna devices was explored. The influences of isostatic pressure on the microstructure and dielectric performance of the samples were systematically characterized. The optimized sample prepared under an isostatic pressure of 270(Formula presented)MPa exhibited the quality factor ((Formula presented) of approximately 16640(Formula presented)GHz at 9.9(Formula presented)GHz and a relative permittivity of about 5.6. In the millimeter-wave frequency range of 25–50(Formula presented)GHz, the dielectric constant varied between 5.1 and 5.9, while the millimeter-wave dielectric loss tangent remained around (Formula presented). Based on the measured dielectric properties, a compact cylindrical dielectric resonator antenna (CDRA) was designed and optimized for the target 5G millimeter-wave band. The fabricated antenna achieved a measured −10(Formula presented)dB impedance bandwidth from 25.0(Formula presented)GHz to 28.5(Formula presented)GHz and a peak gain of 7.5(Formula presented)dBi, together with stable broadside radiation characteristics. Good agreement between simulated and measured results was obtained. These results demonstrate the feasibility of employing room-temperature densified NaCl ceramics as dielectric resonator materials for millimeter-wave antenna systems and provide a promising route toward low-cost dielectric ceramic devices with simplified fabrication processes.