Simulation and Cold Test of the <i>G</i> -Band Ultrawideband Double-Mode Staggered Double-Vane Traveling-Wave Tube

Staggered double-vane traveling-wave tube has garnered significant attention due to its advantages of high power, wide band in high frequency, long service life, planar structure, suitable for high-current sheet electron beam and so on. In this paper, a G-band staggered double-vane travelingwave tube has been designed and verified. During the design process, double-mode working operation has been adopted to further improve the working bandwidth. Simulation results indicate that the under the sheet beam excitation, the proposed design scheme can achieve a peak output power of 220 W at 215 GHz, accompanied by a 3-dB bandwidth exceeding 60 GHz, which fully verify the effectiveness of the double-mode operation on realizing the ultra-wideband power output. Meanwhile, in order to further enhance the practical feasibility of the designed scheme, a planar distributed three-layer structure has been designed in detail, followed by fabrication and cold test to verify the structural correctness. Test results show that the bandwidth and the transmission properties are in good agreement with simulation results, fully verifying the feasibility of the designed planar three-layer structure in fabricating implementation, and further validating the correctness of the double-mode working operation. This proposed scheme holds promise for the development of high-power ultra-wideband terahertz radiation sources, further demonstrating application potential in relevant fields.