Microwave dielectric properties of (Zn 1− xMg x)TiO 3 (ZMT) ceramics for dielectric resonator antenna application

Abstract

Present investigation provides experimental studies on cylindrical dielectric resonator antennas (CDRAs) fabricated from (Zn 1− x Mg x )TiO 3 (ZMT) ceramic material with different substitution of Mg in place of Zn ( x = 0.1, 0.2, 0.3, 0.4 and 0.5) along with measurement of material permittivity in C-band of microwave frequencies. The dielectric properties of the ZMT ceramic materials with different x values ( x = 0.1–0.5) have been measured at microwave frequencies using Hakki–Coleman method modified by Courtney. The value of dielectric constant and loss tangent decreases with the increase in Mg content. The dielectric constant is minimum for x = 0.3 and loss tangent is minimum for x = 0.5. The variations of return loss and input impedance versus frequency and radiation patterns of CDRAs at their respective resonant frequencies are studied experimentally. The measured results for resonant frequency and return loss bandwidth of the CDRAs are also compared with theoretical ones. The measured resonant frequencies of all the four CDRAs are nearly in agreement with respective theoretical values and the values of input resistance at respective resonant frequencies of the CDRAs match well with the coaxial feed impedance of 50 Ω. The designed CDRAs have broad beam, low side lobe and cross-polarized lobe levels.