Supplements to “A Time-Domain Macromodel Based on the Frequency-Domain Moment Method for the Field-to-Wire Coupling”

A macromodel method based on the method of moments was proposed in a previous paper to efficiently and statistically analyze the field coupling to thin-wire structures of arbitrary shape in free space or above the perfectly conducting ground. Through numerical tests and physical insights, it was shown that the extracted macromodel is irrelevant to the port impedances. In this correspondence, a rigorous mathematical derivation is given to prove the irrelevance. The work completes the macromodel method and constitutes its theoretical foundation.