NASA Marshall Space Flight Center (MSFC) has developed a High-Power Solid-State Power Amplifier System that combines 1-KW modules (16 amps total) to generate up to 16KW of radio frequency (RF) power from 230 MHz. The NASA device is a first step toward increasing the power of solid-state power amp devices so that they might replace the more cumbersome vacuum tube amps for some applications. Also, when vacuum tube amps fail, a total power failure occurs. Since the NASA device is a system of amplifiers, it enables graceful failure, meaning one or more stages can fail and the system will continue to operate, although at reduced power.
Existing state-of-the-art power amplification at high powers has been almost exclusively provided by vacuum tube amplifiers. The power levels of current solid-state power amplifiers are quite low (15KW) compared to the power levels of current vacuum tube amplifiers (10s MW); however, the enormous size and weight of the vacuum tube amplifiers can be problematic.
The system includes a receiver, splitters, a set of solid-state amplifier units, multiport combiners, and a level control protection circuit. It enables scalability to allow variable power — 1-, 2-, 3-, 4-, 6-, 8-, 9-, 12-, and 16-KW units are possible. Cost averages $1/Watt ($16,000 for a 16-KW unit). The system provides 1 Watt of output power for every 0.1 to 1.0 pound of weight, compared to vacuum tube amps that generate 1 W for every 1 to 5 pounds of weight.