Accurate Calculation of Mutual Coupling Between Apertures on a Large Coated Cylinder Using Mixed Potential Green's Functions

A rigorous approach based on the closed-form mixed potential Green's function (MPGF) is developed to evaluate mutual coupling between apertures on an electrically large cylinder with dielectric covers. An improved procedure is outlined to provide accurate values of the MPGF both in the near and far field, including the axial line region. The cylindrical functions are represented in the form of ratios to avoid the numerical instabilities, making the MPGF able to handle electrically large problems. As a result, a high degree of accuracy is ensured in the calculation of the mutual admittance between two apertures with large separation on an electrically large cylinder. This approach is validated by comparison with published data, and its ability in dealing with complex and electrically large problems is also verified.