HEMT models for S-parameter and noise parameter extrapolation

Abstract

Four models have been developed and assessed for fitting the measured noise parameters up to 26GHz and Sparameters up to 4OGHz, for a commercial HEMT chip.The first treats the intrinsic noise sources as uncorrelated, thermal sources. The second is an extension of this, allowing a better fit to be achieved by including the distributed nature of the gate and drain electrodes using a semidistributed, sliced model. The third model neglects the distributed effect but takes into account the partial correlation of the gate and drain noise sources. This causes a larger improvement in the quality of fit, allowing the model t o fit the measured data within reasonable measurement limits. Fourthly, the addition of the distributed effect to the correlated model allows a further marginal improvement, but the conditioning of the problem and the accuracy of the data appear to be insufficient to allow accurate extraction of the additional parameters needed.

CAD‐oriented signal and noise modeling of mm‐wave FETs: a wave approach

“…Recent developments in the area of mm‐wave applications of field‐effect transistors (FETs) demand more attention on modeling problems (Hussein et al 2003; Farina et al , 2004) and investigating optimal solutions for future applications of these devices such as phased array radar, remote sensing, mobile and satellite communication. However, if the gate width is comparable to operating wavelength, the wave propagation effect must be taken into account (Golio, 1991; Dambrine, 1998; Hickson, 1992; Bosy, 1995; Schroeder et al , 1997; Farina et al , 1995; Holden, 1985; Alsunaidi et al , 1996).…”