Electromagnetic coupling between wires and loops inside a rectangular cavity using multiple-mode transmission line theory

This paper describes the high frequency coupling between wires and loops inside a large rectangular cavity. A solution is found from the superposition of excited waveguide modes within the cavity. The equivalent transmission line circuit model for each mode is obtained that includes the coupling between each high order mode. Semi-empirical values for the equivalent circuit representing the loop and monopole impedances are also provided. Comparison with experimental results for various locations within the enclosure demonstrate the accuracy of the multi-mode approach. This method is far more computationally efficient than full field solvers and also provides an insight into the coupling mechanisms.