Frequency-Independent T Equivalent Circuit for On-Chip Spiral Inductors

A new T-model has been proposed for on-chip spiral inductors in this letter. In this model, we use less number of elements (only ten elements) than the conventional single-π model (11 elements), but it overcomes the main drawback of the latter. A simple parameter extraction method is proposed to get the elements´ values without any optimization, and a good match with the measured data proves the model´s accuracy up to the resonant frequency. Two partition factors are introduced to demonstrate the asymmetrical characteristics of the spiral layout, and their approximate invariability proves the model´s validity. The factors are directly determined by the extracted model parameters instead of estimation.