Model-Based Low-Frequency Noise Power Spectrum Density Fitting in SiGe HBTs

By using a model based predictive control system, we automatically fit the low-frequency noise (LFN) power spectrum density (PSD) of 375 GHZ silicon germanium heterojunction bipolar transistors (SiGe HBTs). The results show that this method not only offers a more efficient solution compared to the traditional fitting, but also locates the noise sources of LFN more accurately. In addition, it indicates the emergence of cutoff frequency within the low frequency range or other measurement problems which the model can not handle