Noise characteristics of GaAs HBT's

A complete characterization of the bias-, area-, and frequency-dependence of GaAs HBT noise characteristics is presented. It is shown that there is an optimum device area (emitter area) and bias condition for achieving a minimum noise figure, which for the M/A-COM process at 2 GHz occurs at an area of roughly 120 /spl mu/m/sup 2/ and a collector current of 2 mA yielding a minimum noise figure of 1.4 dB and an associated gain of 13 dB. The measured noise characteristics are validated by an extracted equivalent circuit model with associated noise sources.