A low-frequency coupling model from a small circular loop antenna to a transmission line (TL) composed of a single perfect electrical conductor (PEC) wire above a lossy half-space is presented. Instead of using Sommerfeld integrals, a discrete complex images method (CIM) is utilized to calculate the electromagnetic fields produced by a horizontal magnetic dipole (HMD). The resulting currents induced on the TL are subsequently calculated and are validated with a commercial moment method code which uses numerical solutions to the Sommerfeld integral.