The Design, Modeling And Parameter Extraction Of Silicon-Based Sprial Inductors In RFICS

With the development of silicon fabrication technologies and communication industry, the design and characterization of radio frequency integrated circuit (RFIC) have become very hot area in industry and academia. The spiral inductor, the key element of RFICs, has been widely used in RF circuit models, such as the voltage controlled oscillator (VCO), the low noise amplifier (LNA), and power amplifier (PA), matching network. And the on-chip transformers also have been implemented in the of resistance transformators, coupling circuits, DC current insulators and so on. In the past few decades, many people have done lots of theoretical and experimental research works aiming at improving the performance of on-chip spiral inductors. In order to enhance the Q-factor of spiral inductors, scholars have presented many themes to optimize geometries and employing new fabrication technologies, such as adopting the suspended and vertical structures, differentially driven patterns, high resistive silicon, and patterned shielding grounds (PGS).Furthermore, the chip area occupation is one of the crucial problems in IC design. Planar inductors usually occupy more chip area than that of the other on-chip components. Stacked spiral inductors and transformers are proposed in order to reduce chip area and cost. The advanced IC fabrication processes provide multiple metal layers for interconnection, which allows the three-dimensional structure to be used in RF&MM Ics. However, complex interconnections and passive devices are hard to model by simple equivalent circuits. Therefore, accurate modeling, parameter extraction and optimized design are the key points for RF&MM Ics.In chapter 2, some traditional inductors,inductor models and the parameter extraction methodology are reviewed; In chapter 3, the DC inductance calculation method of planar inductors and multi-layer spiral inductors are introduced. Furthermore, the partial element equivalent circuit method which could capture the frequency-dependent series inductance and resistance of multi-layer inductance are presented; In chapter 4, the parameter extraction method of planar transmission line and spiral inductors are depicted;In chapter 5, the design methodologies and procedure of spiral inductors are detailed introduced. Moreover, a novel group-cross differential inductor, which could effectively increase the self-resonant frequency (SRF) by decreasing the self-capacitance, is depicted. Comparing to traditional differential inductors, it has same on-chip area and same inductance. Furthermore, a novel compact circuits model and scalable distributed circuit model of multi-layer spiral inductors that firstly developed by our group are introduced. The good agreement between the modeled results and measurement validates the correctness of our model.