An independently matched parameter SPICE model for GaAs MESFET´s

A GaAs MESFET model is presented that addresses the modeling problem arising from the discrepancy between the derivatives of the dc current and the measured small signal parameters of a GaAs MESFET. This discrepancy traditionally required the user of a non-linear circuit analysis program such as SPICE to trade off the accuracy between the dc analysis and ac analysis. This paper addresses this problem and leads to a solution that completely eliminates the need for such a trade off. Two additional nodes are incorporated into the SPICE MESFET model by providing two extra conducting paths necessary to reconcile the aforementioned discrepancies and to keep the equations self-consistent. In addition, the model allows the user to select different sets of model parameters to independently match I_ds, g_m, and g _ds, An integration scheme to transform the new model back to a 3×3 Y-matrix is employed to accelerate the simulation speed