Design of a low-gain high-power W-band sheet-beam traveling wave tube using a double-staggered grating slow wave structure.

In order to further improve the output power of W-band traveling wave tube (TWT), a low gain TWT was proposed as a secondary amplifier. It uses a double staggered grating slow wave structure (DSG-SWS) and a sheet beam. Firstly, the design of DSG-TWT was given. Through simulation, the DSG-TWT could provide a saturation output power of more than 1000 W in the frequency range of 93–97 GHz, and the maximum output power could reach 1200 W at 95 GHz. No oscillation and current interception were found. Then DSG-SWS was fabricated by E-plane partition method using high-precision CNC milling. The SWS was fed with a high-power input-output coupler which consists of a mode converter and an impedance transformer. Simulation and cold-test results were presented, showing that the S11 is less than −10 dB and the voltage standing wave ratio (VSWR) is less than 2.0 in the frequency range of 93–100 GHz. [ABSTRACT FROM AUTHOR]