The applicability of three methods, including iterative and asymptotic approaches based on generalized transmission line (TL) theory and modified classical TL method based on second radiation, for high frequency field coupling to TL is investigated. The induced current along transmission lines with different structure exposed to high frequency plane wave is calculated using these methods and classical TL theory respectively, and results are compared to full wave analysis commercial software NEC solutions. All the results show that the methods based on generalized TL theory are applicable for both low and high frequency plane wave coupling to TL, while classical TL theory only is suitable for the circumstances where TL approximations hold. However, modified classical TL theory may provide better results than classical TL theory when used at high frequency. Experimental results demonstrate the effectiveness of approach based on generalized TL theory. Finally, the advantages and inapplicability of those methods are summarized.
