STUDY OF HIGH EFFICIENCY NOVEL FOLDED WAVEGUIDE TRAVELING-WAVE TUBE WITH SHEET ELECTRON BEAM

A novel double-ridge loaded folded waveguide (FWG) traveling-wave tube (TWT) amplifier for sheet electron beam working at 140 GHz is proposed in this paper. The dispersion relation and interaction impedance characteristics have been analyzed based on the equivalent circuit method. The transmission properties and nonlinear interaction are investigated. The simulation results reveal that the double-ridge loaded FWG-TWT with sheet electron beam can make full use of relatively large electronic fields, and the average output power can be over 110 W at 140 GHz when the electron beam voltage and the current of the sheet beam are set to 12.7 kV and 150 mA, respectively. Meanwhile, the maximum gain and interaction efficiency can reach 34 dB and 12%, respectively. Compared with the traditional FWG-TWT, the novel FWG-TWT has the advantages of much higher efficiency and bigger output power.