Abstract: Two different scalable models developed based on enhanced 1-π and 2-π topologies are presented for on-chip spiral inductor modeling. All elements used in the two topologies for accurately predicting the characteristics of spiral inductors at radio frequencies are constructed in geometry-dependent equations for scalable modeling. Then a comparison between the 1-π and 2-π scalable models is made from the following aspects: the complexity of equivalent circuit models and parameter-extraction procedures, scalable rules and the accuracy of scalable models. The two scalable models are further verified by the excellent match between the measured and simulated results on extracted parameters up to self-resonant frequency (SRF) for a set of spiral inductors with different L, R and N, which are fabricated by employing 0.18-μm 1P6M RF CMOS technology.

Key words: RF-CMOS,  on-chip spiral inductor,  scalable model,  1-π,  2-π