Electromagnetic scattering by arbitrarily shaped surfaces with impedance boundary conditions

The impedance boundary condition has been implemented in the electric field integral equation triangular patch model for scattering from arbitrarily shaped, imperfectly conducting surfaces. The impedance boundary condition function has been assumed linear within each triangular face, and discontinuous changes in the impedance value are allowed from face to face. The procedure has been validated by comparison of numerical results obtained with the model and exact solutions for scattering by spheres having uniform impedance boundary conditions. Validation for scattering by objects with discontinuous or nonuniform impedance boundary conditions has been obtained by comparison of triangular patch models with body of revolution models.