Design and Characterization of Integrated Varactors for RF Applications

I Gutierrez, J. Melendez and E. Hernandez
John Wiley & Sons Ltd. • 179 pages; $110
ISBN: 978-0-470-02587-1

This book introduces the reader to varactor design for RF applications in low cost technologies (CMOS, BiCMOS and SiGe) at different levels. It focuses on the design and characterization of integrated varactors. Chapter 1 looks at the general concepts of an integrated varactor, which is characterized by its C-V curve and its figures of merit are the quality factor and the tuning range. Chapter 2 analyses the operating principle of integrated P-N junction varactors and the tools used in their design.

Chapter 3 continues along the same lines and looks at MOS varactors. Design rules for the P-N- and MOS-type varactors are extensively described and compared. The experience of different RFIC designers has been summarized to provide the reader with practical knowledge to employ when dealing with challenging VCO designs and others. Some wide band electrical models (up to 5 GHz) are derived, which enable the prediction of their performance in an accurate way.

These models are based on physical dimensions and on the properties of the fabrication processes, which provide additional information that is valuable at the design stage. Chapter 4 focuses on the characterization methodology. One specific methodology for integrated varactors is proposed for accurate measurements.

It covers the design of on-wafer measurement structures, the calibration process and the detailed description of the equipment required. Chapter 5 looks at the models of varactors and Chapter 6 gives details of the design rules resulting from the work of the previous chapters. Finally, Chapter 7 presents the design of different circuits that use varactors for correct operation, including the design of a voltage-controlled oscillator with a varactor in its LC tank.

To order this book, contact:
John Wiley & Sons Ltd.
The Atrium
Southern Gate, Chichester West Sussex, PO19 8SQ, England
+44 1243 779777

Adaptive Cooling of Integrated Circuits Using Digital Microfluidics

Y. Paik, K. Chakrabarty and V.K. Pamula
Artech House • 203 pages; $89, €41 ISBN: 978-1-59693-138-1

Thermal management is a critical issue in integrated circuit design. In this book, alternative cooling architectures, based on a recently invented “digital microfluidic” platform, are introduced. In Chapter 1, the detrimental effects in digital ICs caused by overheating are explained. While many of the same problems are found in analog integrated circuits, they are typically not as extreme. This chapter continues with the study of the sources of power dissipation, followed by descriptions of practical solutions at the microarchitectural level. Chapter 2 provides a number of examples of methods used for cooling integrated circuits, ranging from simple heatsink-fan implementations to complex MEMS structures, used to enhance air flow and heat dissipation. Several microfluidic devices are also discussed. The fundamental principles of how a droplet moves by electro-wetting are described in Chapter 3. Chapter 4 focuses on the development of the basic digital microfluidic platform toward a cooling platform and deals with two main themes: how to measure the temperature across the surface of the chip and identify hot spots, and how to integrate a digital microfluidic chip with an existing device. The temperature effects on moving droplets in a digital microfluidic platform are studied in Chapter 5. Chapters 6 and 7 investigate two methods of chip cooling using digital microfluidic devices. In a flow through approach, cooling droplets are actuated independently via electro-wetting through user-defined reprogrammable flow paths and speeds. The book ends with some concluding remarks summarizing the crucial components that have made the cooling device possible and proposes potential improvements that should be explored in future studies.

To order this book, contact:
Artech House
685 Canton St.
Norwood, MA 02062
(781) 769-9750 Ext. 4030; or 46 Gillingham St.
London SW1V 1HH, UK
+44 (0) 207-8750