Modeling and analysis of a nonlinear fully distributed FET using FDTD technique

In this paper, a new method for the time-domain analysis of a PHEMT transistor operating in the nonlinear region based on the fully distributed model is presented. Considering a nonlinear lumped equivalent circuit as an active part and applying the finite-difference time-domain (FDTD) technique to solve the equations extracted from this model, the voltages at each point of the electrodes are calculated.The procedure has been applied to a 0.2×1600μm PHEMT with 16 gate fingers operating at 28GHz and the results achieved from MATLAB are compared with semi-distributed model which is simulated by ADS simulator. By using this new method, more accurate results are obtained. This approach can be applied to the transistors used in nonlinear regions at microwave and millimeter-wave frequencies.