Study on W-band sheet-beam traveling-wave tube based on flat-roofed sine waveguide

Abstract

Design and cold test of period-tapered double-ridge-loaded folded waveguide slow wave structure for Ka band TWTs AIP Advances 8, 055105 (2018) A W-band sheet electron beam (SEB) traveling-wave tube (TWT) based on flat-roofed sine waveguide slow-wave structure (FRSWG-SWS) is proposed. The sine wave of the metal grating is replaced by a flat-roofed sine wave around the electron beam tunnel. The slow-wave characteristics including the dispersion properties and interaction impedance have been investigated by using the eigenmode solver in the 3-D electromagnetic simulation software Ansoft HFSS. Through calculations, the FRSWG SWS possesses the larger average interaction impedance than the conventional sine waveguide (SWG) SWS in the frequency range of 86-110 GHz. The beam-wave interaction was studied and particle-in-cell simulation results show that the SEB TWT can produce output power over 120 W within the bandwidth ranging from 90 to 100 GHz, and the maximum output power is 226 W at typical frequency 94 GHz, corresponding electron efficiency of 5.89%. © 2018 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license

Millimeter wave traveling wave tubes for the 21st Century

“…To further simplify the fabrication of the FWG SWSs, and mitigate the ohmic losses, the Sine waveguide has been proposed for wideband, high-power terahertz TWTs (Figure 19(b)). It supports a sheet beam [109][110][111][112][113]. The interaction impedance of the sine waveguide SWS is low compared to a conventional FWG leading to a longer beam-wave interaction circuit, which will bring a challenge to the electron optical system.…”