An improved model for noise characterization of microwave GaAs FETs

A broadband noise model for microwave FETs has been described. The model consists of small-signal lumped elements together with two noise sources. A measurement of broadband S parameters plus a single-frequency measurement of optimum source susceptance can yield enough information to determine the model, although greater accuracy is obtained using additional noise data to determine the precise value of the gate resistance. The model's predictions match well with measured noise parameter data for a high-performance GaAs FET over a wide frequency range