Numerical analysis of high frequency GaAs FET transistor using alternating direction implicit (ADI) finite-difference time-domain method; Distributed modeling approach

The unconditionally stable ADI Finite Difference Time Domain (FDTD) method is used to govern the distributed model equations of high frequency GaAs FET transistor. This implicit scheme with no constraint by a stability criterion is exploited to increase the time performance of the CPU time considerably compared with the conditionally stable methods such as explicit Leap-Frog (LF) FDTD scheme. Moreover, the ADI method can effectively decrease the complexity of the sparse matrix structure emerging in Crank–Nicolson (CN) FDTD scheme by splitting it into two time increments. The accuracy of the ADI is appreciated to the LF, CN and measured results.