Description:
Spatial power combining provides a viable  solution to the realization of solid-state power sources and amplifiers at microwave and millimeter-wave frequencies, with power levels that can not be achieved by a single solid-state device.   A patented waveguide-based spatially-combined solid-state power amplifier concept has been developed at UCSB  to aimed at realizing wide band, efficient microwave power amplifier using commercial MMIC technology. 

The X-band wave-guide-based combiner systems use stacked trays of broadband tapered-slot antennas integrated with commercial MMIC amplifiers, housed in a wave-guide environment that is operated in the dominant TE10 mode. Each antenna is then essentially a waveguide-to-transmission line transformer that couples energy from the wave-guide mode to a set of power amplifiers.  The hybrid circuit configuration is independent of the device technologies and allows for excellent thermal management. In addition, the modular architecture allows easy maintenance, variable power output and potential medium-scale fabrication.

Our first demonstration used 8 commercial GaAs MMICs in a 4-tray design, producing 40Watts from 8-11GHz with  excellent gain flatness.  This was attributed to optimized antenna designs (design of the finline arrays is described on a separate project page).  This prototype was then scaled, with careful attention to thermal management,  to a 24 MMIC design using 6 copper -trays with 4 MMICs per tray.  This system generated 120Watts in X-band, with graceful degradation characteristics.  Ultimately a 32 MMIC version was demonstrated using 32 MMIC in a slightly oversized waveguide. 

MAFET Final Review, March 1999