Fabrication of high dielectric constant and low loss X band ceramic waveguide window for High power applications

An attempt has been made to fabricate and analyze the transmission of microwave power and bandwidth through an X band waveguide window filled with a material having high dielectric constant and low dielectric loss. In this study, the single phase Ba(Zn1/3Ta2/3)O3 (BZT) BZT material is synthesized through solid-state reaction method. The microwave dielectric properties of BZT samples measured using Vector network analyzer with Hakki-Coleman setup. The obtained dielectric properties used to fabricate the dielectric window in waveguide structure and dielectric window is simulated using a finite difference time domain (FDTD) based software (IMST's Empire). The simulation work is carried out by varying thickness of ceramic window while keeping dielectric constant and loss tangent fixed to study the effect of window thickness on power transmission. The dielectric constant effect on power transmission is also studied by varying dielectric constant while keeping the window thickness constant. The maximum power transmission obtained for a BZT window of thickness 2.85mm at 10 GHz with bandwidth of 2.07 GHz corresponds to a S21 magnitude of 0.019 dB and return loss at the same frequency is −48dB.