GaAsING UP FOR QUICKER ASW SIGNAL PROCESSING SPEEDS.

With Soviet submarines getting quieter every year there is a need for more efficient Antisubmarine Warfare Systems. One emerging technology showing great promise in addressing this need involves a semiconductor compound called gallium arsenide, but the technology to use the compound is still comparatively primitive - when matched with current advances with sister silicon semiconductor compounds. Scientists at Varian's Research Center in Palo Alto developed a GaAs ultrabroadband distributed amplifier that delivers significantly more gain at a lower noise figure than previously achieved. The new amplifiers are based on HEMT (High Electron Mobility Transistor) technology that yield more than 10 dB single stage gain over the 2-20 gigahertz frequency band. Stage gain by the HEMT amplifiers is as high as four times that of the more conventional metal semiconductor field effect transistor (MESFET) devices, and the noise figure represents improvement by a factor of two over currently available amplifiers.