New CAD models for spiral inductors and EM coupling for EM based circuit design

摘要

This thesis contributes several techniques for electromagnetic-based computer-aided modeling, design, optimization and simulation of RF/microwave components and circuits. First, computer-aided design (CAD) of spiral inductors exploiting full-wave electromagnetic (EM) analysis is proposed. Traditional optimization methods for spiral inductors rely on circuit models and they are inaccurate compared to EM simulations. Space-mapping optimization combines the speed of circuit models and the accuracy of EM simulations. A space-mapping optimization algorithm is proposed which yields an EM-validated spiral inductor design/layout with considerable improvement over those obtained by traditional optimization methods. Second, a very compact composite low-pass filter is presented. It offers good matching properties in the pass-band and features an attenuation pole near the cutoff frequency leading to a sharper attenuation response. The filter is implemented using spiral inductors and metal-insulator-metal capacitors. The filter occupies a compact area of 1.4mm{604}0.8mm which is much smaller than other filters operating in the same frequency range. The measured response of the overall circuit might not match or could be entirely different from the expected response, even if the passive components are designed accurately. This is because coupling between components can play an important role in the circuit performance especially in dense circuits. An efficient and recent CAD model for EM coupling, previously applied to passive EM circuit simulation, is considered. This CAD technique is applied to EM coupling modeling of a nonlinear RFIC consisting of both active and passive components. The efficiency of the technique is demonstrated through an amplifier circuit simulation