SAW amplifiers on multilayer GaAs substrates

The SAW amplifier was a topic of considerable interest twenty years ago and in light of numerous material advances in compound semiconductors since that time, perhaps should be revisited. One of the limitations of this device was the excessive power consumption due to the inability to grow very high resistivity semiconductor films with high electron mobility. In addition, the high drift voltages on the order of hundreds of volts made the devices impractical for commercial system applications. In this paper we implement a SAW amplifier on a multilayer GaAs substrate. Fabricating the device on a thin (<1 μm), lightly doped n-type (n₀~10¹⁴) epitaxial layer of GaAs enables a very high sheet resistance to be obtained while maintaining the high electron mobility of GaAs