Investigation of 0.14THz pill-box window for folded waveguide TWT

Abstract

A broadband pill-box window with sapphire piece for 0.14THz folded waveguide traveling wave tube is manufactured. Cold-test result shows the attenuation of the window is about 0.7dB during 0.13THz-0.15THz. Using the back-to-back method, the RF coupling system including pill-box and taper waveguide is test. The result shows that the VSWR is less than 1.2, which meets the practical requirements in 0.14THz folded waveguide TWT.