Scattering by Multiple Arbitrary Circular Cavities Loaded in a PEC Plane

In this letter, an efficient solution based on the modal expansion method for the analysis of wave scattering from multiple arbitrary circular cavities placed in a perfect electric conductor is presented. Unlike most of the existing methods that employ the Graf's addition theorem, which brings serious problems, we employ the complex function method cooperating with multipolar coordinate transformation to match tangential fields in analyzed regions. Finally, unknown expansion coefficients are computed by solving the system of linear equations and the Fourier series. Some typical examples are given to verify the solution by the method of moments.