FDTD calculations for nonlinear lumped loads

Transient currents for a wire antenna with a nonlinear diode load are calculated directly using finite-difference time-domain (FDTD) methods. In the FDTD cell that contains the load, a nonlinear equation is solved at each time step. As a test case the transient current in a long dipole antenna with a nonlinear load excited by a pulsed plane wave is computed. The results agree well with both calculated and measured results previously published. The approach given allows the time step to be set at the Courant limit and can be applied to scattering from targets with nonlinear loads and materials, to nonlinear harmonic generation, and to propagation through nonlinear materials.<>