Computation of scattering field for impedance coated bodies

In order to obtain the solutions of the scattering field for large and complex bodies, a formula is derived from the Stratton-Chu integral equation under conditions of high-frequency, far-field, and the physical optics approximation. When calculating the surface integral, the impedance surfaces are divided into a large number of surface elements. These small grids are approximated by planar elements. the scattering field of the planar elements is expressed as an algebraic sum, so that the time-consuming integral operation can be avoided. The advantages of this method are simplicity and high speed. Numerical results on a coated plate and sphere show the validity of the method.<>