Ultra-high Q×f and low εr of microwave dielectric ceramic SrYb2O4 with mitigated rattling effect and design of dielectric resonant antenna for 5 G applications

Abstract

Binary rare-earth oxides exhibit promising potential for applications in high-frequency wireless communication devices due to their low permittivity and adjustable resonant frequency. However, a significant challenge remains in achieving ultra-low dielectric loss. The rattling effect of cations is the primary structural factor that influences losses and has become an important method for modulating dielectric properties. In this work, we propose a strategy to mitigate the rattling effect of cations by regulating the ion radius difference between Sr and Ln (lanthanide), reducing the microwave dielectric loss of SrYb₂O₄ ceramic. The SrYb₂O₄ ceramic was prepared at 1450 °C, exhibiting a low ε_r of 16.1, a negative τ_f of −31.33 ppm/°C, and an ultra-high Q×f of 118,777 GHz. The ε_r and τ_f were affected by the ionic polarizability and the bond valence. The reduction of the cationic rattling effect resulted in a higher Q×f. Furthermore, a dielectric resonator antenna was designed for 5 G communication applications.