Design and analysis of a waveguide window for W-Band TWT

A waveguide window is designed for W-Band folded waveguide TWT. The window performance is initially designed by the transmission line theory and then optimized by 3D EM simulation code CST MWS, HFSS and MTSS. The results of these codes are in agreement and all show us that the waveguide window has excellent transmission performance from 90GHz to 102GHz with VSWR less than 1.1 and S11 less than −30dB.