Dielectric characterization of BiVO4 -TiO2 composites and applications in microwave range

Abstract

This paper reported the dielectric and structural characterization of composites formed by mixture of BiVO4 and TiO2 and applications in microwave range. The composites were formulated by addition of TiO2 (15, 30, 45 and 60 wt %) in BiVO4. X-Ray Diffraction (XRD) was used in structural characterization. The dielectric properties, temperature coefficient of resonant frequency (τf), dielectric permittivity (ε) and dielectric loss (tan δ), were measured and the results confirm that the TiO2 addition improves the thermo-stability of the composites with values varying from −244.03–246.12 ppm.0C−1. The dielectric properties varied with TiO2 composition (31<εr < 67) with dielectric loss around 10−3 values. These composites were analyzed as Dielectric Resonator Antenna and all samples showed can be applied as antenna (all presented S11 below −10 dB). The numerical studies of these antennas presented good agreement with experimental results in which the bandwidth, return loss and input impedance had small errors.