This expanded and thoroughly revised edition of Thomas H. Lee's acclaimed guide to the design of gigahertz RF integrated circuits features a completely new chapter on the principles of wireless systems. The chapters on low-noise amplifiers, oscillators and phase noise have been significantly expanded as well. The chapter on architectures now contains several examples of complete chip designs that bring together all the various theoretical and practical elements involved in producing a prototype chip. First Edition Hb (1998): 0-521-63061-4 First Edition Pb (1998); 0-521-63922-0

The Design of CMOS Radio-Frequency Integrated Circuits: RF CIRCUITS THROUGH THE AGES

The results of a comprehensive investigation into the characteristics and optimization of Inductors fabricated with the top-level metal of a submicron silicon VLSI process are presented. A computer program which extncts a physics-based model of microstrip components that is suitable for circuit (SPICE) simulation has been used to evaluate the effect of variations in melallization, layout geometry, and substrate parameters upon monolithic inductor performance. Three-dimensional (3-D) numerical simulations and experimental measurements of inductors were also used to benchmark the model aecuncy. It is shown in this work that low inductor Q is primarily due to the restrictions imposed by the thin interconnect metallization available in most very large scale integration (VLSI) technolocies, and that computer optimization of the inductor layout can be used to achieve a 50% improvement in component Q-factor over unoptimized designs.

The Modeling, Characterization, and Design of Monolithic Inductors for Silicon RF IC's

Delivering milliwatts of wireless power at centimeter distances is advantageous to many existing and emerging biomedical applications It is highly desirable to fully integrate the receiver on a single chip in standard CMOS with no additional post-processing steps or external components This paper presents a 2 $\,\times \,$ 218 ${\rm mm}^{2}$ on-chip wireless power transfer (WPT) receiver (Rx) coil fabricated in 013 $\mu {\rm m}$ CMOS The WPT system utilizes a 145 $\, \times \,$ 145 ${\rm mm}^{2}$ transmitter (Tx) coil that is fabricated on a standard FR4 substrate The on-chip power harvester demonstrates a peak WPT efficiency of $-1847~{\rm dB}$ , ${-2096}~{\rm dB}$ and $-2015~{\rm dB}$ at 10 mm of separation through air, bovine muscle and 02 molar NaCl, respectively The achieved efficiency enables the delivery of milliwatts of power to application circuits while staying below safe power density and electromagnetic (EM) exposure limits

Fully Integrated On-Chip Coil in 0.13 $\mu {\rm m}$ CMOS for Wireless Power Transfer Through Biological Media

This paper presents a CMOS-compatible process for fabrication of 3D structures embedded in the volume of a silicon wafer, and capable of interconnection to circuitry on the wafer surface. The key challenge of embedding structures in the silicon substrate is processing inside deep silicon trenches. This difficulty is overcome by means of several key techniques: multilevel wafer etching; cavity shaping; fine proximity lithography at the bottom of trenches; and laminated dry-film lithography on complex 3D structures. As a technology demonstration, a topologically complex 3D toroidal inductor is fabricated in a deep silicon trench, and is coupled to the wafer surface with high-power, electroplated through-wafer interconnect. Inductors fabricated in these trenches achieved an overall inductance of 60 nH, dc resistance of 399 MΩ, and quality factor of 17.5 at 70 MHz.

Silicon-embedded 3D toroidal air-core inductor with through-wafer interconnect for on-chip integration

Inductors are primary elements in many radio frequency circuitries and devices. This review gives a comprehensive survey on the developments and performances of fixed and variable RF MEMS inductors. MEMS inductors are the core of this review due to their high-yield performances and the wide choices of possible tuning techniques. First, the factors that constrain high-performance micro coils and the conventional solutions to overcome them are highlighted. Next, this paper systematically reviews varieties of MEMS inductors starting with the fixed inductors and according to inductors' topologies and performance enhancement techniques. In addition, the variable types of inductors are subsequently discussed, mainly from the point of view of their tuning techniques. Many quantitative comparisons are given in terms of the values of quality factor, inductance, self-resonance frequency, and tuning range. This will provide readers with an overall evaluation of different studies and assist them in choosing the inductors' topologies and layouts that best suit their applications. This review also sheds light on different and most common RF MEMS inductors applications, including RF communication devices and wireless sensors and actuators applications. Finally, this paper summarizes the best fabrication and tuning approaches inferred from the reviewed works and discusses some design guidelines to achieve better inductor performance.

RF MEMS Inductors and Their Applications--A Review

This paper presents micromachined solenoid inductors that are fabricated in a standard CMOS silicon substrate (with a resistivity of 1-8 Omega  cm) The solenoid is concavely embedded in a silicon cavity with the silicon wafer surface remaining a plane, and mechanically suspended to form an air gap from the bottom of the silicon cavity In addition to facilitating flip-chip packaging, this so-called "concave-suspending" technique effectively depresses the substrate effects including eddy current and capacitive coupling between the coil and the substrate, therefore contributing to both high Q -factor and high resonant frequency of the inductors for high-performance radio-frequency (RF)/microwave integrated circuit applications Various inductors with different solenoid layouts, eg, several shapes of curved solenoids, have been successfully fabricated by using a post-CMOS microelectromechanical systems process that employs copper electroplating, tetra-methyl-ammonium hydroxide (TMAH) + iso- propanol etching and compensation control for convex-corner undercutting, photoresist spray coating, XeF2 gaseous etching, and other steps A lumped circuit model that accounts for inter- turn fringing capacitance, capacitance between the coil and the substrate, substrate ohmic loss and substrate capacitance, etc, is derived for the solenoid inductors The accuracy of the model is confirmed by the testing results and can be used for optimal design of the inductors By S-parameter testing, various types of inductors with different solenoid layouts have been evaluated The solenoid inductors generally exhibit improved RF performance in Q-factor and self-resonance frequency compared to their conventional counterparts

Lei Gu

Papers

High- $Q$ Solenoid Inductors With a CMOS-Compatible Concave-Suspending MEMS Process