A Hybrid Excitation Method of Finite-gap Port Model and Plane Wave in SIE for Electromagnetic Problems

By combining finite-gap port model with the plane wave source, a hybrid excitation method in surface integral equation (SIE) is presented to solve the electromagnetic problems, e.g., scattering, radiation, and electromagnetic interference. Such as, this method can be applied in the radiation situation that a microstrip antenna is excited by a delt-gap voltage source, and is also illuminated external electromagnetic waves. In actual, this hybrid excitation model includes the radiation excitation model and scattering excitation model. Namely, for radiation excitation model, adopting the finite-gap port model, which includes current and voltage sources. Noted that a small gap region is identified as a two-terminal port and the fields in the gap are linked to the voltage or current definition. Two conditions are required to be enforced. One is the line integral of the electric field along straight paths in the gap being equal to the port voltage. The other is the current conducted into/out of the gap region being identical and equal to the port current. This port model is implemented by modifying the traditional method of moments (MoM) solution to use a novel divergence-conforming testing function at the gap as well as half-RWG basis functions connected across the gap. And the half-RWG basis functions are defined on the opposite edge triangles at the two-terminal. For the scattering excitation model, the plane wave model is adopted. Several numerical results are also provided to demonstrate that in comparison with the traditional SIE, the hybrid excitation method combined in SIE shows more flexible in complex electromagnetic problems, e.g., simulating interconnection and packaging circuit, nuclear radiation, and multiple antenna interference, etc.