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-pi 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.