This paper proposes an efficient PSP-based model for cross-coupled metal-oxide-semiconductor field-effect transistors (MOSFETs) with optimized layout in the voltage controlled oscillator (VCO). The model employs a PSP charge model to characterize the bias-dependent extrinsic capacitance instead of numerical functions with strong non-linearity. The simulation convergence is greatly improved by this method. An original scheme is developed to extract the parameters of the PSP charge model based on S-parameters measurement. The interconnection parasitics of the cross-coupled MOSFETs are modeled based on vector fitting. The model is verified with an LC VCO design, and exhibits excellent convergence during simulation. The results show improvements as high as 60.5% and 61.8% in simulation efficiency and accuracy, respectively, indicating that the proposed model better characterizes optimized cross-coupled MOSFETs in advanced radio frequency (RF) circuit design.

关键词： Layout optimizing,  Modeling,  PSP,  Charge model,  Cross-coupled,  Metal-oxide-semiconductor (MOS),  Voltage controlled oscillator (VCO)