Comparison and model of on-chip transmission lines with and without metal grounding in CMOS process

This paper investigates the properties of the on-chip transmission lines with and without metal grounding based on measured data. Physical equivalent-circuit models are employed to evaluate the transmission lines with different ground planes, and the model parameters to predict the characteristics in the oxide layer were established and compared refer to the physical mechanism. Two different structures of transmission lines are fabricated in standard 0.18 μm RF CMOS process, and model parameters are extracted from the on-wafer measured S-parameters up to 50 GHz.