FDTD Analysis of Small Signal Model for GaAs MESFETs Based on Three Line Structure

We have studied the effect of wave propagation along the electrodes of a GaAs MESFET using fully distributed model. A three coupled lines theory, including active and passive electromagnetic coupling between semiconductor electrodes is used to analysis. Each distributed device element is considered as a combination of three coupled lines and a conventional equivalent circuit of a GaAs MESFET. The equations derived from the fully distributed equivalent circuit are solved using Finite-Difference Time Domain (FDTD) technique. The procedure is applied to a pi GaAs MESFET and the scattering parameters are computed from time domain results over a frequency range of 1-40 GHz.