Synthesis Techniques and Optimizations for Reconfigurable Systems
Ryan Kastner, Majid Sarrafzadeh · 2003
book starts with an introduction to the many circuit applications of inductance and the integrated circuit (IC) fabrication process. Inductor performance is described in terms of the IC technology such as CMOS, SiGe, BiCMOS, and GaAs. Some discussion is given on the various loss mechanisms and the challenge of integrating high-quality inductors on chip. The circuit applications start with a brief description of an LC tank network and extend into the world of LNAs, VCOs, and RF filters. The physics of the inductors are covered in some detail with a discussion of the difficulty of integrating an inductor on chip, followed by a graphical description of the magnetic and electric field generated by the timevarying signal applied to the two ends of the inductor. The authors describe both the self- and mutual inductance and provide a physical basis for both. Much of the discussion is very general and cursory; however, ample references are provided. Resistance effects due to the finite resistance of the inductor metal, as well as skin effect due to high-frequency operation, are also described. Other parasitic effects that contribute to inductor loss are mentioned, including proximity effects and substrate lose mechanisms such as electrically and magnetically induced loses. Inductor models are briefly mentioned, including the standard model and variations of the model. Some discussion is also provided on the various electromagnetic field solvers that can be used to simulate inductors. Quality factor (Q) is defined in the standard way as the ratio of the maximum energy stored in the inductor to its average power dissipation of a duty cycle. Design techniques for improving inductor Q are reviewed, including broken guard rings, biased N-well beneath the inductor, and substrate shielding with broken polysilicon patterned ground shields that are tied to ground. References are provided for each improvement technique. A chapter is included on test and characterization techniques, describing the test equipment necessary to make accurate inductor measurements. It also illustrates the design of the highfrequency ground-signal-ground probes and the various probing techniques that are required to provide good planarization and pad contact. The authors provide a discussion of the various error terms that arise when measuring inductors and spend some time discussing the merits and types of calibration. The book concludes with an in-depth discussion of the geometrical influence on inductor performance. This book serves as an excellent