SURFACE ACOUSTIC WAVE FUNCTIONAL DEVICE

摘要

A surface acoustic wave functional element is provided with a semiconductor layer on a piezoelectric substrate or piezoelectric thin film substrate and utilizes the interaction between surface acoustic waves propagated on the surface of the substrate and electrons in the semiconductor layer. The semiconductor layer is formed outside the propagating path of the surface acoustic waves and provided with a plurality of grating electrodes perpendicularly to the propagating path, an active layer, and a buffer layer lattice-matched with the active layer. Using this surface acoustic wave functional device, a surface acoustic wave amplifier with a high amplification degree at a practical low voltage is provided, and a surface acoustic wave convolver having such a high efficiency that has not been achieved so far, is provided.