Ding Chong

A dielectric-embedded microstrip meander line slow-wave structure for miniaturized traveling wave tube

Abstract A modified microstrip meander line (MML) slow-wave structure (SWS) embedded with dielectric rod for miniaturized traveling wave tubes (TWTs) is presented in this paper. High-frequency characteristics, fabrication processes, and beam-wave interaction of the modified MML SWS are analyzed. Compared with conventional MML SWSs supported by dielectric substrate, the modified MML SWS possesses a wider cold bandwidth (about 53.5% increased) and larger interaction impedances (about 21.4% increased). Moreover, this modified MML has better connection with the dielectric, which may improve the slow-wave structure’s stability and reliability under thermal shock, stress impact, and electron bombardment. The beam-wave interaction simulation results indicate that TWTs using the modified MML SWS is capable of delivering 75.85 W saturated output power, corresponding a gain of 28.8 dB and an electron efficiency of 6.32% at the frequency of 35 GHz, with the sheet electron beam of 6000 V and 200 mA.