Wide Temperature Behavior Analyses of SiGe HBTs Based on Small-Signal Parameter Extraction Method

This work analyzes the temperature characteristics of RF small-signal parameters for SiGe HBTs over a range of 80 K to 400 K. By extracting small-signal model parameters, we investigate how temperature variations affect device performance. The findings reveal significant enhancements in cut-off frequency from 189 GHz at 400 K to 406 GHz at 80 K, highlighting the suitability of SiGe HBTs for cryogenic applications and advanced RF circuit designs.