Compact Models Based on Transmission-Line Concept for Integrated Capacitors and Inductors

This paper presents a compact modeling methodology for inductors and capacitors based on transmission-line theory. Using continued fractions approximation, second- and third-order intrinsic inductor and capacitor models are demonstrated. With the second-order model, one can accurately predict inductor and capacitor behavior up to their first resonance frequencies. With the third-order model, one can match the measured inductor or capacitor response beyond the first resonance frequency. Wideband accurate passive models developed here are essential for transient and harmonic-balance analysis where out-of-band frequencies are important. The model parameters are extracted directly from S-parameter measurement without a need for optimization. Furthermore, the frequency-dependent nonlinear effects of spiral inductors and metal-insulator-metal capacitors are expressed based on simple models without resorting to frequency-dependent parameters