Synthesis and characterization of complex pervoskite BMT ceramics and the effect of gamma radiation at microwave frequency

Ba(Mg 1/3 ,Ta 2/3 )O 3 (BMT), a complex perovskite ceramic with extremely high Q u and that has been the only choice as dielectric resonator (DR) for satellite multiplexers extensively used in communication satellites. BMT DRs have been prepared by solid-state route by single-step calcinations followed by firing the green compacts at about 1600–1650 °C for 20 h. Excellent Q u -factor > 20,000 at 10 GHz achieved after annealing near 1000 °C combined with near-zero τ f and dielectric constant ( ε r ) ~ 24. The DRs are subjected to 100 kRad and 1MRad γ irradiation exposure. The resonant frequency and Q u are measured after the irradiation and found to be within the range of measurement error. This paper briefly discusses the BMT processing, characterization, the properties and the effects of γ -radiation. These BMT DRs are useful for Satellite applications. The ten-pole filters have been assembled and its performance tested and verified.