An Innovative Two-Source Large-Signal Measurement System for the Characterization of Low-Frequency Dispersive Effects in FETs

Large-signal measurement systems based on high-frequency sinusoidal excitations have been widely exploited by the microwave community for the characterization of transistors under nonlinear operation. However, device characterization at high-frequencies necessarily involves the application of rather complex calibration procedures of the measurement setup. In addition, reactive effects associated with the device extrinsic parasitic effects tend to become more important at high-frequencies. Thus, uncertainties in the identification of the parasitic network components may leads in this case to critical errors in the identification of the intrinsic device behavior and in particular, of the drain current source. In order to overcome these problems, an alternative nonlinear measurement setup based on large-signal sinusoidal excitation at low-frequency (e.g., 2 MHz) is here proposed. The description of its hardware and software implementation is dealt with in this paper and different experimental examples are provided in order to highlight the capabilities of the proposed characterization approach.