Two signal extraction techniques, including one in the frequency domain and one in the time domain, are developed for the time-domain analysis of microwave devices fed by a transmission line, for which only one FDTD calculation is needed, and an incident wave and a reflected wave in both the time domain and frequency domain can be acquired from time-domain total waves. The former is applicable to dispersive and lossy transmission lines, and the latter is applicable to only nondispersive and lossless ones, bat the latter has higher accuracy than the former. By comparison with two FDTD calculations, time-domain analysis in combination with two signal extraction techniques can reduce the computer expense. (C) 1999 John Wiley & Sons, Inc.