Basic EMC Technology Advancement for C(3) Systems. Volume IV A. Coupling of Electromagnetic Fields onto Transmission Lines: A Comparison of the Transmission Line Model and the Method of Moments.

摘要

The coupling of electromagnetic fields onto transmission lines is investigated. The transmission line model which with distributed sources is employed as a computationally efficient method of predicting currents induced on transmission wires by an incident field. Results obtained from the transmission line model solution are compared with predictions made by the more rigorous, but much less efficient, method of moments technique. Two user-oriented computer codes, using different expansion and testing functions, have been selected to provide the method of moments solution. Both the prediction accuracy and limitations of the transmission line model are explored in depth using a carefully selected transmission line structure. The structure is modified slightly to illustrate several important characteristics of the transmission line model solution. Low frequency limitations of the method of moments solution are investigated. In addition, the differences between the two method of moments formulations are found to have a significant effect on the integrity of their individual solutions. These differences are illustrated. Finally, the practical use of the transmission line model as an effective method for predicting the coupling of an electromagentic field into terminal devices is discussed.