An improved millimeter-wave small-signal modeling approach for HEMTs

An improved method to determine the small-signal equivalent circuit model for HEMTs is presented in this study, which is combination of the analytical approach and empirical optimization procedure. The parasitic inductances and resistances are extracted under pinch-off condition. The initial intrinsic elements are determined by conventional analytical method. Advanced design system (agilent commercial circuit simulator) is used to optimize the whole model parameters with small deviation of initial values. An excellent agreement between measured and simulated S-parameters is obtained for 2 × 20 μm² gate width HEMT up to 40 GHz.