Characterization and model of 4-terminal RF CMOS with bulk effect

Special test structures using separated source and bulk contacts with the 3/sup rd/ GSG probe for the substrate bias are described. These test structures allow characterizing 4-terminal MOSFETs with a standard two-port Network Analyzer. The high-frequency behavior of bulk effect in MOSFETs is studied at different bias conditions for a 0.18 /spl mu/m RF CMOS technology. Measurement result of RF NMOSFET shows that a good accuracy of the 4-terminal RF MOSFET modeling is achieved. The validity and accuracy of our approach is verified and analyzed from two-port Y-parameter results.