A simple four-port parasitic deembedding methodology for high-frequency scattering parameter and noise characterization of SiGe HBTs

A new four-port scattering parameter (S-parameter) and broad-band noise deembedding methodology is presented. This deembedding technique considers distributed on-wafer parasitics in the millimeter-wave band (f>30GHz). The procedure is based on simple analytical calculations and requires no equivalent circuit modeling or electromagnetic simulations. Detailed four-port system analysis and deembedding expressions are derived. Comparisons between this new method and the industry-standard "open-short" method were made using measured and simulated data on state-of-the-art SiGe HBTs with a maximum cutoff frequency of approximately 180 GHz. The comparison demonstrates that better accuracy is achieved using this new four-port method. Based on a combination of measurements and HP-ADS simulations, we also show that this new technique can be used to accurately extract the S-parameters and broad-band noise characteristics to frequencies above 100 GHz.