Numerical Modeling of Active Devices Characterized by Measured S-Parameters in FDTD

A new FDTD modeling approach for active devices characterized by measured S-parameters is presented. This approach applies vector fitting technique and piecewise linear recursive convolution (PLRC) technique to complete modeling process, and does not need to know the equivalent circuits of active devices. It preserves the explicit nature of the traditional FDTD method, and a general updated formula is derived. Furthermore, the main data-processing procedure is directly handled over the frequency band of interest, which avoids the time-domain non-causal error in traditional techniques.