This paper presents a time domain analysis of electromagnetic coupling in microwave circuits, focusing on a multiconductor transmission line (MTL) subjected to various nonlinear terminations. The authors utilize the Finite Difference Time Domain (FDTD) technique to compute voltage and current expressions effectively, demonstrating good agreement with measurements from a transverse electromagnetic (GTEM) cell. The work highlights the importance of understanding external electromagnetic fields' influence on electronic systems to ensure their proper functioning and EMC compliance.