Measurement and modeling of noise parameters for desensitized low noise amplifiers

It can be shown that devices with low noise resistance (R_n) values can significantly relax the noise-input match trade-off in LNA design, resulting in desensitized wideband LNAs. In this paper, we show that the measurements of such devices are error-prone and can cause modeling and simulation inaccuracies. Using a CAD-oriented approach, an error-propagation analysis from measurements to a device-model is performed. We find that the errors in measurements affect the simulated values of R_n, NF_min and B_opt the least and these parameters need to be calibrated well in any good device model. Values of G_opt are shown to propagate from measurements and errors are bigger for devices with a large transadmittance (_y21). We suggest the use of scaled MOS models extracted from devices with high R_n to predict the values of G_opt for devices with low R_n, using the other noise parameters as calibration points.