Finite‐Difference Time‐Domain Method

This chapter focuses on the most widely used numerical model: the finite-difference time-domain (FDTD) method. It investigates electromagnetic (EM) plane wave behaviors both in time and frequency domains. A TL made from two conductors (a pair of parallel wires) is accepted as the fundamental structure and the theory is established according to this assumption. The theory, basic concepts, and characteristic equations explained in the chapter may be obtained either from EM wave theory or independently from the circuit theory. The chapter discusses the time-domain reflectometer concept, which has been widely used in fault location and identification in TLs. It then discusses one-dimensional (1D) FDTD with second order differential equations, and moves onto review the plane wave and the transmission line (TL) problems. Finally, the chapter focuses on two-dimensional (2D) FDTD models. Most of EM problems including radiation and beam forming/beam steering, scattering, and propagation modeling are handled in 2D.