A study on the noise parameters of active devices based on a circuit model approach

Noise parameters of high electron mobility transistors (HEMT) at microwaves are a subject of active research since the knowledge of their performance is of key importance to the use of these devices in low-noise applications. In this work, a simple noise model associated to the basic equivalent circuit of an HEMT has been employed to derive the analytical expressions for the device noise parameters Fo, Γo and N. Such expressions have then been analyzed for establishing some fundamental relationships, as well as the expected noise performance of the device when the parasitic elements representing package effects are added.