A compact G-band MPM power amplifier for high-resolution airborne radar

A compact, upper-mm-wave, microwave power module (MPM) power amplifier operating in G-band from 231.5 GHz to 235 GHz has been developed at L3 Electron Devices. Two MPM configurations have been tested: The first, intended for laboratory use, consists of a single-housing containing a PPM-focused serpentine waveguide traveling wave tube and a compact 20 kV high voltage power supply. This MPM provides a peak output power of 41 dBm at 234 GHz when driven with 7 dBm input. The second MPM is configured for use in a modified tactical airborne gimbal. It employs a custom split-package architecture consisting of separate power supply and RF modules, along with interconnecting cabling. This unit has been qualified for airborne operation up to 20 kft (6 km) and provides greater than 44 dBm at 234 GHz when driven with 11 dBm input drive. Both MPMs operate from 270 VDC prime power and at duty factors up to 50%. Radar waveforms have been processed through both amplifiers. We believe this development represents the first realization of an integrated G-band MPM.