Efficient modeling of the coupling from a small circular loop to a multi-conductor transmission line above a lossy ground

A low-frequency coupling model consisting of a multi-conductor transmission line (TL) system and a small circular loop antenna is presented. The TL system is composed of N perfect electrical conductor (PEC) wires above a lossy ground. An approximate and computationally efficient analytical method is proposed to predict the current distribution on each wire. The total electromagnetic (EM) fields produced by the small circular loop antenna above the lossy half-space are calculated by employing a discrete complex image method (DCIM). The resulting induced current distributions are subsequently calculated and validated with a commercially available moment method code.