Transistor noise parameter extraction using a 50 Omega measurement system

A 50- Omega noise-figure measurement system has been integrated into a fully automated S-parameter measurement system, allowing fast determination of transistor noise parameters as well as S-parameters as a function of both frequency and bias. This functionality from such a simple measurement system is achieved using a novel analysis technique, based on the noise temperature model (see M.W. Popieszalski, 1989), that allows, after S-parameter measurements and analysis, the direct extraction of all four transistor noise parameters from a single noise-figure measurement. The value of the unknown temperature T/sub d/ and the physically relevant small-signal model circuit element values determined provide the CAD (computer-aided design) database necessary to model both the scaling behavior of the transistor S-parameters and noise parameters and their extrapolation to millimeter-wave frequencies.<
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