Evaluation of scattering parameters, gain, and feedback‐capacitance‐dependent noise performance of a pseudomorphic high‐electron‐mobility transistor

This paper evaluates microwave performance in terms of scattering parameters and gains and presents the effect of gate‐to‐drain capacitance C gd on the noise behavior of a pseudomorphic high‐electron mobility transistor (PHEMT). An analytical expression for C gd is obtained and the influence of gate length, epilayer thickness, and gate and drain bias upon this PHEMT is studied. Analytically calculated small‐signal parameters are used to evaluate the intrinsic and extrinsic scattering parameters and gains of the PHEMT. Finally, the dependence of bias and frequency on minimum noise figure, scattering parameters, and gains is studied. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 51–57, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21079