Structure property correlation of (1-x)MgTiO3 - xSrTiO3 microwave dielectric ceramics for dielectric resonator antenna applications

Abstract

The current paper reports on the crystal structure, microwave dielectric properties as well as the antenna parameters of (1-x)MgTiO3 - xSrTiO3 (abbreviated as (1-x)MT-xST) for x = 0.025, 0.05, 0.075, 0.1 ceramic based dielectric resonator antennas (DRAs). The (1-x) MT - xST samples have been prepared with the help of a solid-state reaction route. The SrTiO3 was introduced to MgTiO3 as a τf compensator for developing a tunable τf material. Rietveld refinement results of X-ray diffraction data suggest that all the samples exhibit a combination of two crystallographic phases i.e., rhombohedral (R-3) + cubic (Pm-3m). The SEM micrographs show clear and well-defined grains for (1-x)MT - xST (for x = 0.025–0.1) ceramics. The modes of vibration of the crystal structures of the materials have been identified by the Raman spectroscopy method. The bond strength, bond valency, bond energy, and tolerance factor have been determined for (1-x)MT - xST (for x = 0.025–0.1) materials. The microwave dielectric performances of ceramics have been analyzed over a frequency band of 1–10 GHz. It has been found that the dielectric constant is almost constant along the microwave frequency range. The behavioral change of tuned temperature coefficient of resonant frequency (τf) along with quality factor have been reported. Besides, DRAs have been formed using all ceramic compositions, and simulations were performed to determine the various antenna properties, such as efficiency, input impedance, radiation properties, gain, and reflection coefficient. This study supports the use of microwave dielectric ceramics in antenna fields and highlights the enormous potential of (1-x)MT - xST for (x = 0.05) materials in communication systems.