Study on Interchannel Coupling and Power Synthesis in Multichannel Serpentine Groove-Guide Slow Wave Structures

In this article, a power synthesis scheme based on multichannel serpentine groove-guide (MC-SGG) structure is proposed to enhance output power and investigate interchannel coupling effects in multichannel traveling-wave tubes (TWTs). Comprehensive error analysis of the multichannel power synthesis process is conducted to evaluate its sensitivity to dimensional tolerances and beam current mismatches. Electromagnetic simulations validate the high-frequency characteristics of the MC-SGG slow wave structure (SWS), while subsequent field analysis reveals coupling effects between adjacent channels. These coupling phenomena are further confirmed through the particle-in-cell (PIC) algorithm. Simulation results indicate that the designed MC-SGG-TWT achieves an output power of 816 W at 94 GHz, with a gain of 26 dB and an efficiency of 7.3%. Under a fixed beam voltage of 18.6 kV and a total current of 0.6 A, the 3-dB bandwidth covers 9296.5 GHz. These results demonstrate the feasibility of the MC-SGG structure for high-power, broadband applications and provide a detailed investigation of multichannel interaction mechanisms in integrated TWT systems.