Fuzzy Logic based Method for the Extraction of Extrinsic and Intrinsic Elements of Microwave Transistors

In this paper we propose a new method for the extraction of extrinsic and intrinsic elements for microwave transistors based on a fuzzy logic architecture. The proposed technique uses the experience of the designer in order to extract and optimize in a smart way only the electrical elements required for an accurate multibias scattering parameters prediction. We tested our model with a GaAs MESFET 6 x 120 um and a Al GaAs P-HEMT 6 x 15 um device. It has been demonstrated that the proposed method is more accurate than the conventional one, evaluated with the previous technologies. The global behavior of the transconductance (gm) and gate to source capacitance (Cgs) measured with this technique agrees with the physical properties of the above mentioned technologies. Another advantage of this method is that the conventional “Cold-FET” configurations (Vds=0V) are not required, which warrant the reliability of the microwave transistor. The methodology presented in this work can be used in the RF circuit design industry as a first step for an accurate transistor characterization.