Direct amplification of high-frequency electric waves in semiconductors

A theoretical analysis is given of the possibility of using coupled acoustoplasma waves in the amplification of electric signals. It is shown that in such waves the electric energy is comparable with the elastic energy. Equations fox slowly varying amplitudes are derived and analyzed. The Weinreich relationship is generalized to the average force exerted on carriers by a growing wave. The steady-state operation of an acoustoplasma amplifier is discussed in detail.