Identify Resonant Frequencies Early in a Simulation

Common practice among XFdtd users is allowing simulations to reach a -30 dB, or lower, level of convergence. This is highly recommended for the stages in a design where all results must be accurate. However, other stages in a design have less stringent accuracy requirements. When locating resonant frequencies is the primary objective, a higher level of convergence is often sufficient. Although the specific level varies per project, -1 dB to -10 dB should be considered.

XF can generate broadband frequency domain plots, like S-Parameters, in real-time during the simulation. By monitoring these plots, which automatically update, early detection of resonant frequencies can be accomplished. Once a frequency has been locked on, meaning the null in S-Parameters changes depth, but does not shift frequency, the simulation can confidently be terminated and the next iteration begun.