Effect of the stability factor on the accuracy of two-dimensional TD-FD simulation

The effect of the stability factor on the computational accuracy of the time-domain finite-difference method using Maxwell´s two curl equations is systematically tested for an initial boundary value problem in electromagnetics. A rectangular waveguide is chosen as the computational domain with matching and reflecting boundaries in two dimensions. The TE/sub 10/ mode is excited as an initial condition. A standing wave envelope is numerically formulated; s/sub max/ and S/sub min/ are sampled as in slotted-line measurements. Simulation results for different values of the stability factor are compared with the value ´unity´ of the standing wave envelope in the matched condition. Generally, accuracy is not very sensitive to variations in the stability factor. But better accuracy has been observed at around SF=0.7 than at lower values of the stability factor. For both accuracy and economy reasons the authors suggest that a stability factor close to 0.7 should be chosen.<>