The microwave dielectric characteristics and mixture behavior of (1 − x)CaWO 4 -xTiO 2 ceramics prepared with conventional solid-state route were studied using a network analyzer and X-ray power diffraction, respectively. The CaWO 4 compound had good properties (low permittivity and high quality factor) for microwave applications, but it had a high negative temperature coefficient of resonant frequency (τ f = −53). Hence, in order to tune the dielectric properties, (1 − x)CaWO 4 -xTiO 2 were prepared for different values of x. X-ray powder diffraction and SEM analysis revealed that CaWO 4 and TiO 2 coexisted as a mixture. The mixture formation and dielectric properties could be explained by mixture rule. In particular, at x = 2.6, good microwave dielectric properties were obtained: Qf = 27,000, ε r = 17.48, and τ f = ∼0 ppm/ • C.

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