Reflection of transverse waves in a structure “dielectric-piezoelectric semiconductor with current”

Reflection of a plane monochromatic transverse wave by the boundary of the acoustic contact of a dielectric with a hexagonal piezoelectric semiconductor in the presence of a longitudinal charge drift is treated in the small-signal approximation within the framework of the hydrodynamic description of a charge carrier plasma. A procedure of selecting the branches with allowance for the conversion of the quasi-acoustic mode (a refracted transverse wave) into plasma-acoustic disturbances, both in-leaking at the boundary or out-leaking from it, is proposed for the determination of the solution under the conditions of a supersonic drift and “overcritical” angles of incidence. Beyond the restrictions of White’s theory of ultrasonic wave propagation in piezoelectric semiconductors, it is demonstrated that this technique removes the defects of the solutions obtained earlier in the form of discontinuities in angular dependences of the modulus of the reflection coefficient of a transverse wave in the vicinity of the “critical” angle of incidence and leads to a solution that does not contain a resonance singularity of a polar type.