Microwave/THz Vacuum Electronics

Terahertz (THz) waves (~0.1 to 10 THz) have tremendous potential for applications including ultra-fast (femto-second) phenomena studies, high-data-rate communication networks, tumor/cancer scans, living cell imaging (4D-tomography), nondestructive device inspection, hydro dynamics analysis, nano-compound spectroscopy, and sub-wavelength microscopy/lithography. However, the most critical problem is the absence of an appropriate watt-level radiation source, which can provide several orders of magnitude signal-to-noise ratio with broad spectral coverage. Recently, micro vacuum electron devices (µVEDs) have received considerable attention as a possible breakthrough for high power THz source development owing to their high energy conversion efficiency and large thermal power capacity. This approach requires linear scale-down of bulky VED elements, which is made possible by advances in microfabrication technology which have opened the way to miniaturize bulky vacuum electronic circuits down to the sub-millimeter scale, which enables the development of portable THz radiation source. In the DRC, we have developed UV lithographic microelectroforming techniques for the fabrication of the required ultra-thick metallic microstructures (≥ 400 µm) with sidewall surface roughness of ~ 50 - 100 nm. The vacuum electronics research areas at the DMRC include:

  • Ultra-wideband sheet beam TWT amplifiers for THz communication, sensing, and imaging applications
  • High power THz sheet beam klystrons
  • Broadband THz backward wave oscillators (BWOs)
  • Plasmonic devices
  • Gyro-TWTs

Recent Projects

  • 220 GHz, 30% bandwidth, 150 W packaged amplifier [PDF]