ABSTRACT

This chapter discusses the application of FDTD to problems that involve nonlinear circuit elements or materials. Dealing with nonlinearities is comparatively easy in the time domain as opposed to frequency domain calculations. Frequency domain approaches often involve iteration processes that themselves may involve transformation back and forth between frequency and time domains. Working directly in the time domain is often much simpler, because the parameters of the device or material may be modified as a function of the field strength in the FDTD cell as the computation progresses. In most situations this is not without some added computational effort, as the time step size often must be set much lower than normally required in order to avoid instabilities in the FDTD calculations.