Wide-band distributed modeling of spiral inductors in RFICs

A new wide-band model for planar spiral inductors on silicon substrate consisting of ideal lumped elements is presented. The equivalent circuit model captures the distributed behavior of the spiral for electrically large devices in particular with low self-resonant frequency. A fast, automated extraction procedure is developed for determining the circuit element values from two-port S-parameter data. The new modeling methodology is applied to extract a distributed model from the measured S-parameters of an electrically large 1.5-nH spiral. The extracted model shows excellent agreement with the measured data over a frequency range of 0.1 to 10 GHz.