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

Abstract

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\u2009W in the frequency range of 93–97\u2009GHz, and the maximum output power could reach 1200\u2009W at 95\u2009GHz. 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\u2009dB and the voltage standing wave ratio (VSWR) is less than 2.0 in the frequency range of 93–100\u2009GHz.