An area source for exciting a microstrip line in an FDTD simulation is proposed and studied in this paper. More accurate S-parameters are obtained by using the area source rather than the discrete source for exciting microstrip lines. This study also shows that both voltage area source and current area source work equally well. The reason for the improvement of S-parameters calculation due to the use of the area source is explained. The simulation results obtained by using the area source are also compared with those obtained by using the waveguide port.
