Design of Dielectric Resonator Antenna by (1–x) MZTO–(x) CSTO Microwave Dielectric Ceramic

Abstract

In this paper we present the studies on microwave dielectric composites, (1-x)(Mg_0.95 Zn_0.05 )TiO_3-x(Ca_0.8 Sr_0.2 )TiO_3.
The materials have been prepared by solid state method and the co– existence of both the phases with no traceable interdiffusion has been confirmed by the studies done using X–ray Diffractometer and Scanning Electron Microscope. The microwave dielectric properties of these composite materials have also been investigated. We have observed a dielectric constant (ϵ_r) of 21.9, a dielectric loss〖(tan〗〖δ)〗of 0.0002, and temperature coefficient of resonant frequency (τ_f) of –0.15 ppm/ºC for 0.92(Mg_0.95 Zn_0.05 )TiO_3-0.08(Ca_0.8 Sr_0.2 )TiO_3 ceramic, sintered at 1300 ºC for 4 h which is found suitable for antenna application. We have designed the cylindrical dielectric resonator antenna  (DRA) using this material; the DRA has been excited by coaxial probe feeding mechanism. The variations of return loss versus frequency and far field radiation patterns of the DRA at the respective resonant frequency have been simulated by finite element method (Ansoft High Frequency Structure Simulator). The simulated results have been compared with the
measured results and a good agreement is achieved between these results.