0.850 THz vacuum electronic power amplifier

Northrop Grumman Electronic Systems has developed the first, compact, microfabricated vacuum electronic amplifier operating at 0.835–0.875 THz. The amplifier produced >50 mW of output power at the window at frequencies between 0.835–0.842 THz and 39.4 mW of output power at 0.850 THz. The amplifier exhibited 26 dB of small signal gain and 11 GHz of instantaneous bandwidth. The compact power amplifier is based on a DRIE-fabricated folded waveguide slow-wave circuit, together with a high current density thermionic cathode, a high field permanent magnet solenoid, and a single-stage depressed collector for overall device efficiency.