Intermodulation distortion of nonlinear piezoelectric surface waves

Abstract The designers of acoustic wave devices used in modern signal processing are frequently impeded by inadequate predictions of intermodulation distortion. An examination, up to third order, is made here of this effect which occurs as a consequence of the nonlinear interaction of harmonic frequencies of quasiharmonic surface waves propagating co-directionally on an anisotropic piezoelectric substrate. The governing coupled amplitude partial differential equations which follow from a multiple scales analysis are presented, before representative numerical solutions are given for the practically-typical purely-elastic and piezoelectric materials magnesium oxide and lithium niobate, respectively.