A novel wide-band high-transmission window for high-frequency microwave tubes

In this work, we present a new window design for high-frequency microwave tubes, which eliminates most of the disadvantages and also permits broadband operation and high power output. The window is thick enough to be easily brazed and it exhibits a wide bandwidth and high transmission. The design is carried out for a 35 GHz Ka-band traveling wave tube. The numerical simulation is performed via the finite-element code, high frequency structure simulator (HFSS). The results show that the bandwidth for the transmission of 99, i.e., S₁₁ below -20 dB, can be optimized to be about 8.75 GHz or 25. This design is novel and has general significance. A wide-bandwidth window for a W-band tube can be easily designed and fabricated, or even higher frequency.