A Simplified Approach for Automatic Extraction of Model Parameters of Spiral Inductors for Design of MMICs

A simplified parameter-extraction technique is presented for accurately modeling on-chip spiral inductors in microwave monolithic integrated circuits (MMICs) and radio frequency integrated circuits (RFICs). The proposed model is a pi-circuit with RC network connected with both vertical branches to account for substrate coupling. The extraction process starts with series inductance and resistance at low frequencies. Then, the feedback capacitance between two metal layers on which inductor is fabricated is evaluated. Afterward, the substrate resistance and capacitance, is extracted at higher frequencies. All circuit element values of the network are analytically determined from simulated S- parameters obtained from momentum and validated with the measured S- parameters of a 2 turn inductor fabricated on 200 um GaAs (Gallium Arsenide) substrate for frequency up to 26 GHz. The extraction of equivalent network for 1–6 turns of inductor has also been carried out with S-parameter input from momentum simulator.