We present an analytical approach to extract model parameters for silicon on-chip spiral inductors taking into account various high-order parasitic effects such as skin effect and substrate coupling. The parameters for the series branch were extracted using iterative analytical calculations, and parameters for the substrate branch were extracted using a modified linear characteristic-function approach via the introduction of a partition rule. As demonstrated by a series of inductors fabricated using 0.18 mu m CMOS process, simulations can provide a high-precision fit with experimental data over a broad frequency range between 0. 1 and 10 GHz. (c) 2006 Elsevier Ltd. All rights reserved.