Development and application of a 1/f transistor noise measurement technique

This paper introduces and addresses several subtle aspects to the performance of 1/f or flicker noise measurements on microwave transistors. A straightforward measurement system can be assembled using a dynamic signal analyzer, vector signal analyzer, or spectrum analyzer, however, there are a number of potential pitfalls that will prevent accurate measurements. These include bias supply noise, extemal electromagnetic interference (including that from your own bench!), device instability, as well as the dependence of the results on the resistive elements comprising the bias supply filtering or voltage divider networks. This work shows that good results can be achieved with a relatively simple setup after systematically eliminating the influence of these extemal factors on the 1/f noise measurements of interest. A Labview program was written to facilitate the data acquisition and data manipulation for the simple lowcost setup utilized in this work. Example measurements are shown for microwave MESFET. BJT, and a SiGe HBT to illustrate the techniques.