Resonant diffraction from a grating on a paramagnetic layer with frequency dispersion

Theoretical results on the plane electromagnetic wave diffraction from a structure as a strip periodic grating on a paramagnetic layer, the permeability of which possesses negative real part in the microwave band, are obtained using analytical regularization based on the solution to the Riemann-Hilbert problem. The effect of the resonant transmission accompanied by extremely high absorption is thoroughly studied across the frequency band of the surface waves of the paramagnetic layer placed in the biasing magnetic field. This effect is caused by the surface waves of the layer excited resonantly by the plane incident wave with the diffraction grating present. The resonant frequency is electronically tuned by the biasing magnetic field.