Study on a Microfabricated Slow-Wave Structure for the Millimeter-Band Backward-Wave Oscillator Based on the Pseudospark-Source Electron Gun

The truncated sine-waveguide slow-wave interaction structure for the high-power millimeter-band backward-wave oscillator with a pseudospark-sourced sheet electron beam was fabricated using CNC micromilling. The results of morphology studies by scanning electron microscopy (SEM), optical microscopy, and stylus profilometry demonstrate good dimension tolerance and surface quality suitable for operation in the millimeter band. Electromagnetic parameters of the fabricated slow-wave interaction structure were measured in Q-, V-, and W-bands using a vector network analyzer with frequency converters. The results of experimental studies show good transmission and reflection characteristics. Dispersion characteristic was also experimentally measured and compared with numerical simulations.