Diffraction radiation of a slot into a space over an impedance screen

A numerical analytic problem solution of a diffraction radiation of a narrow rectilinear slot into space over an infinite impedance screen is presented. An asymptotic solution for the magnetic current in the slot was obtained by a generalized method of induced magnetomotive forces (MMF) applying the Green's functions for the space above the impedance plane. Influence of the screen impedance coating on a slot is taken into account as an additive to an external conductivity of the slot element. Expressions for slot conductivities were obtained in an analytical form. This approach is common for diffraction problems for which excitation by magnetic currents are solved for various configuration of external regions.