Notes on EFIE-PMCHWT Formulation for Feeding Gaps on Printed Conductors

The combination of the electric-field integral equation (EFIE) and the Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) integral equation is a reasonable approach for analyzing objects composed of conducting and dielectric/magnetic materials. In the EFIE-PMCHWT method of moments for printed conductors, the equivalent magnetic currents on the conducting sheets may be discarded to avoid additional unknowns and singularity in the integral operator. However, the formulation for feeding gaps on the conducting sheets in this approach has not been clarified. In this letter, the necessity of considering the fields yielded by the magnetic currents in the feeding gaps is theoretically explained and numerically demonstrated.