A new calculation approach of transistor noise parameters as a function of gatewidth and bias current

In this paper a new method to calculate the noise parameters of transistors T; (MESFET or HEMT) as a function of gatewidth and drain-bias current is presented. This method needs the knowledge of the R, P, and C coefficients. It is based on the measurement of the noise parameters of a reference transistor Tr at two bias points (/dsi and 7ds2), and the equivalent circuit elements' values of all transistors T;. Using this method, the noise parameters (F_min, r_opt, R_n) for two MESFET's T; biased at another current i_ds3 are obtained. Good agreement between the predicted and measured noise parameters' values is obtained for a broad frequency range (4-20 GHz).