Finite-Difference Time-Domain Simulation of Arbitrary Impedance using One Port S-Parameter

Many modern radio-frequency devices comprise both lumped-element components and complex geometries. Simulation of such a device requires modeling the electromagnetic interactions with both geometric features and lumped components. We present a method for including arbitrary lumped-element components into finite-difference time-domain (FDTD) simulations. The lumped-element components, which are described by their scattering parameters, are modeled in the Yee grid as dependent voltage sources. The mathematical formulation is described, along with its implementation into a FDTD simulator. For verification, simulation results of resistive, capacitive, and inductive loads are presented, and are compared to simulation results from previous lumped-element FDTD methods. This represents a first-step in modeling multiport networks described by their scattering parameters.