Electromagnetic Field Coupling Between a Horizontal Loop Antenna and a Transmission Line: An Analytical Time-Domain Model

The time-domain electromagnetic (EM) reciprocity theorem and the Cagniard-DeHoop technique are applied to analyze the pulsed EM coupling between a horizontal small loop antenna and a finite transmission line above the perfect ground. It is demonstrated that this approach yields closed-form analytical formulas describing the impact of transmission, EM propagation, and reception on the exciting pulse signature. Moreover, approximate expressions applying to relatively short transmission lines are given and discussed, thus revealing similarities with the loop-to-loop EM coupling. Numerical results are presented and validated using an alternative analytical solution and an EM computational tool.