A Novel Wideband 1-π Model with Accurate Substrate Modeling for On-Chip Spiral Inductors

A novel wideband 1-pi equivalent circuit model for on-chip spiral inductors is presented. A substrate network, consisting of R/L/C, is proposed to model the broadband loss mechanisms in the silicon substrate. The skin and distributed effects for windings have been taken into account. A series of inductors with different geometries are fabricated in standard 0.18-mu m 1P6M RF CMOS process to verify the model. Excellent agreements have been obtained between the modeled and measured data up to 40 GHz, which verify that the proposed 1-pi model naturally has better wideband prediction capability than published 1-pi or T-models, and simpler topology than 2-pi models for on-chip spiral inductors.