RF and microwave noise optimization of UHV/CVD SiGe HBTs

This paper demonstrates a predictive noise estimation methodology for SiGe HBTs which combines AC measurement, calibrated AC simulation and two of the latest Y-parameter-based noise models. The current and frequency dependence of the minimum noise figure, the optimum generator admittance, and the noise resistance are simulated and compared with measurements. The observed agreements and discrepancies are investigated using circuit analysis of the chain noisy two-port representation. The SPICE model description of thermal noise produces a better overall agreement to data for the devices under study.