Design of a V-band High-power Sheet-beam Coupled-cavity Traveling-wave Tube

The design and analysis of a high-power wideband sheetbeam coupled-cavity traveling-wave tube operating at V-band is presented. The interaction circuit employs three-slot doubly periodic staggered-ladder coupled-cavity slow-wave structure, and a 5 : 1 aspectratio sheet electron beam is used to interact with the circuit. Combined with design of the well-matched input and output couplers, a 3-D particle-in-cell model of the sheet-beam coupled-cavity traveling-wave tube is constructed. The electromagnetic characteristics and the beamwave interaction of the tube are investigated. From our calculations, this tube can produce saturated output power over 630Watts ranging from 58 GHz to 64GHz when the cathode voltage and beam current are set to 13.2 kV and 300mA, respectively. The corresponding saturated gain and electron efficiency can reach over 32.5 dB and 15.9%. Compared with the circular beam devices, the designed sheetbeam TWT has absolute advantage in power capability, and also it is more competitive in bandwidth and electron efficiency.