Development and cold testing of vacuum RF window for C band 250 kW CW power klystron

The paper deals with the design fabrication and cold testing of vacuum RF window for C-band 250 kW CW power klystron. The simulation of the window has been carried out using the CST microwave studio software. The proposed window is designed for 5 GHz operating frequency for handling 250 kW of RF power. In the proposed window geometry, metallized alumina disc (99.5 % purity) of diameter 56 mm and thickness 1.5 mm is brazed in a cylindrical waveguide of diameter 56 mm. The cylindrical waveguide is terminated to WR 187 waveguide at its both ends. The return loss and insertion loss of the above mentioned window has been found to be -48 dB and 0.05 dB respectively which are well matched with experimental values. The bandwidth of 170 MHz was achieved. The window performance has been found satisfactory for microwave transmission.