Due to the unprecedented growth in wireless applications over the past decade, development of low-cost solutions for RF and microwave communication systems has become of great importance. This practical new book is the first comprehensive treatment of lumped elements, which are playing a critical role in the development of the circuits that make these cost-effective systems possible. The books offers you an in-depth understanding of the different types of RF and microwave circuit elements, including inductors, capacitors, resistors, transformers, via holes, airbridges, and crossovers. Supported with over 220 equations and more than 200 illustrations, it covers the practical aspects of each element in exceptional detail. No other single volume treats this subject matter in such depth. From materials, fabrication, and analyses - to design, modeling, and physical, electrical, and thermal applications, this unique resource offers you complete coverage of the critical topics you need understand for your work in the field. Offering the most comprehensive, up-to-date body of knowledge on lumped elements, the book is an indispensable professional reference and serves as an excellent text for senior undergraduate and graduate-level courses in RF and microwave circuit design.

Lumped Elements for RF and Microwave Circuits

This review of design principles for implementation of a spiral inductor in a silicon integrated circuit fabrication process summarizes prior art in this field. In addition, a fast and physics-based inductor model is exploited to put the results contributed by many different groups in various technologies and achieved over the past eight years into perspective. Inductors are compared not only by their maximum quality factors (Q/sub max/), but also by taking the frequency at Q/sub max/, the inductance value (L), the self-resonance frequency (f/sub SR/), and the coil area into account. It is further explained that the spiral coil structure on a lossy silicon substrate can operate in three different modes, depending at first order on the silicon doping concentration. Ranging from high to low substrate resistivity, inductor-mode, resonator-mode, and eddy-current regimes are defined by characteristic changes of Q/sub max/, L, and f/sub SR/. The advantages and disadvantages of patterned or blanket resistive ground shields between the inductor coil and substrate and the effect of a substrate contact on the inductor are also addressed in this paper. Exploring optimum inductor designs under various constraints leverages the speed of the model. Finally, in view of the continuously increasing operating frequencies in advancing to new generations of RF systems, the range of feasible inductance values for given quality factors are predicted on the basis of optimum technological features.

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On the design of RF spiral inductors on silicon

Microelectromechanical Systems. Fundamental MEMS Device Physics. Fundamental MEMS Devices: The MEMS Switch. Fundamental MEMS Devices: The MEM Resonator. Microwave MEMS Applications. MEMS-Based Microwave Circuits and Systems.

Introduction to Microelectromechanical(MEM)Microwave Systems

Fully CMOS-compatible, highly suspended spiral inductors have been designed and fabricated on standard silicon substrates (1/spl sim/30 /spl Omega//spl middot/cm in resistivity) by surface micromachining technology (no substrate etch involved). The RF characteristics of the fabricated inductors have been measured and their equivalent circuit parameters have been extracted using a conventional lumped-element model. We have achieved a high peak Q-factor of 70 at 6 GHz with inductance of 1.38 nH (at 1 GHz) and a self-resonant frequency of over 20 GHz. To the best of our knowledge, this is the highest Q-factor ever reported on standard silicon substrates. This work has demonstrated that the proposed microelectromechanical systems (MEMS) inductors can be a viable technology option to meet the today's strong demands on high-Q on-chip inductors for multi-GHz silicon RF ICs.

/pdf/cmos-compatible-surface-micromachined-suspended-spiral-xukqqynxr4.pdf

CMOS-compatible surface-micromachined suspended-spiral inductors for multi-GHz silicon RF ICs

In this paper, a robust micromachined spiral inductor with a cross-shaped sandwich membrane support is proposed and fabricated with fully CMOS compatible post-processes for radio frequency integrated circuit (RFIC) applications. Using the incorporation of a sandwich dielectric membrane (0.7 /spl mu/m SiO/sub 2//0.7 /spl mu/m Si/sub 3/N/sub 4//0.7 /spl mu/m TEOS) to enhance the structure rigidity, the inductor can have better signal stability. In comparison, the new design of a /spl sim/5-nH micromachined inductor can have 45% less inductance variation than the one without the dielectric support while both devices are operated with 10 m/s/sup 2/ acceleration. Meanwhile, using a cross shape instead of blanket membrane can also effectively eliminate the inductance variation induced by the working temperature change (20/spl deg/C to 75/spl deg/C). The measurement results show the robust inductor can have similar electrical performance to the as-fabricated freely suspended inductor, which has five times Q (quality factor) improvement than the inductor without the substrate removal. It is our belief that the new micromachined inductors can have not only high-Q performance but also better signal stability suitable for wide-range RFIC applications.

https://ir.nctu.edu.tw:443/bitstream/11536/13514/1/000230123100028.pdf

A robust high-Q micromachined RF inductor for RFIC applications

A silicon micromachining method has been developed to fabricate on-chip high-performance suspended spiral inductors. The spiral structure of an inductor was formed with polysilicon and was suspended over a 30-/spl mu/m-deep cavity in the silicon substrate beneath. Copper (Cu) was electrolessly plated onto the polysilicon spiral to achieve low resistance. The Cu plating process also metallized the inner surfaces of the cavity, forming both a good radio-frequency (RF) ground and an electromagnetic shield. High quality factors (Qs) over 30 and self-resonant frequencies higher than 10 GHz have been achieved. A study of the mechanical properties of the suspended inductors indicates that they can withstand large shock and vibration. Simulation predicts a reduction of an order of magnitude in the mutual inductance of two adjacent inductors with the 30-/spl mu/m-deep Cu-lined cavity from that with silicon as the substrate. This indicates very small crosstalk between the inductors due to the shielding effect of the cavities.

/pdf/on-chip-spiral-inductors-suspended-over-deep-copper-lined-1lwmktj0o7.pdf

N.C. Tien

Papers

On-chip spiral inductors suspended over deep copper-lined cavities