Phenomena of coupling of wave beams and surface wave at impedance plane with spatially oscillating parameters are theoretically considered. Used method is asymptotic with respect to smoothness parameter and is numerical with respect to perturbation amplitudes. It combinesadvantages of the asymptotic and numeric methods in cases of quasiperiodic structures with large number of "periods". Coupling coefficients are obtained for complex amplitude of resonance harmonic. Nonreciprocal Bragg phenomena are analyzed.
展开▼