Microwave dielectric properties of temperature‐stable (Na _0.5 Bi _0.5 )MoO ₄ –SrMoO ₄ ceramics sintered at ultra‐low temperature

Abstract Ever‐growing wireless communication industry demands low loss dielectric ceramics with exceptional microwave dielectric properties and ultra‐low sintering temperatures. In this work, a solid solution (1 − x )Na 0.5 Bi 0.5 MoO 4 – x SrMoO 4 referred as (1 − x )NBM– x SM ( x = 0.4–0.9) was prepared through replacing (NaBi) 2+ by Sr 2+ . X‐ray diffraction analysis (XRD) revealed a solid solution ceramics characterized by a tetragonal scheelite structure. Scanning electron microscopy (SEM) and relative density further confirmed the formation of low porosity and high density scheelite solid solution ceramics. Optimum microwave dielectric performance with a relative permittivity of 15.48, value of 18 763 GHz and a near‐zero temperature coefficient of resonant frequency ( = +2.7 ppm/°C) was achieved at x = 0.7 composition with ultra‐low sintering temperature of 660°C. In order to validate its microwave device application, a prototype dielectric resonator antenna (DRA) was fabricated using the 0.3NBM–0.7SM ceramic. DRA showcased excellent radiation performance, with impedance bandwidth of 200 MHz at a working frequency of 6.83 GHz and realized gain of 5.66 dBi. The co‐firing investigations demonstrate Ag powder exhibits excellent chemical compatibility with the (1 − x )NBM– x SM ceramics, confirming a promising potential of the (1 − x )NBM– x SM ( x = 0.4–0.9) solid solution ceramics for ultra‐low temperature co‐fired ceramics‐based microwave application.