Source excitation methods for the finite-difference time-domain modeling of circuits and devices

Two different types of source excitation for finite-difference time-domain (FDTD) simulations, i.e., electric and magnetic field types, are investigated in this work for configurations that have no ground planes. This paper shows that the electric field excitation introduces errors in the computed admittance of the device due to the frequency dependence of the gap admittance, while the magnetic field excitation does not suffer from this drawback; consequently, the latter is better suited for circuit simulations.