Microfabrication and Micromachining for Millimeter-Wave Traveling Wave Tubes

Millimeter and sub-millimeter wave vacuum electronic devices are of great interest for a wide variety of applications, but fabrication of the sub-wavelength structures has been a persistent challenge. We present several fabrication approaches including CNC micromachining, 3D printing, and UV-photolithography for creating traveling wave tube (TWT) circuits at 35, 95, 140 and 233 GHz, along with test results
^1,2
. To date, CNC micromachining has yielded the best results up to 140 GHz.