Design, Simulation and Applica

The modern wireless communication industry has put great demands on circuit designers for smaller, cheaper transceivers in the gigahertz frequency range. One tool which has assisted designers in satisfying these requirements is the use of on-chip inductive elements (inductors and transformers) in silicon (Si) radio-frequency (RF) integrated circuits (ICs). These elements allow greatly improved levels of performance in Si monolithic low-noise amplifiers, power

amplifiers, up-conversion and down-conversion mixers and local oscillators.

Inductors can be used to improve the intermodulation distortion performance and noise figure of small-signal amplifiers and mixers. In addition, the gain of amplifier stages can be enhanced and the realization of low-cost on-chip local oscillators with good phase noise characteristics is made feasible.

In order to reap these benefits, it is essential that the IC designer be able to predict and optimize the characteristics of on-chip inductive elements. Accurate knowledge of inductance values, quality factor (Q) and the influence of adjacent elements (on-chip proximity effects) and substrate losses is essential. In this book the analysis, modeling and application of on-chip inductive elements is considered. Using analyses based on Maxwells equations, an accurate and efficient technique is developed to model these elements over a wide frequency

range. Energy loss to the conductive substrate is modeled through several mechanisms, including electrically induced displacement and conductive currents and by magnetically induced eddy currents. These techniques have been compiled in a user-friendly software tool ASITIC (Analysis and Simulation of Inductors and Transformers for Integrated Circuits). This tool allows circuit and process engineers to design and optimize the geometry of on-chip inductive devices and the IC process parameters affecting their electrical characteristics.

The wireless communication revolution has spawned a revival of interest in the design and optimization of radio transceivers. Passive elements such as inductors,capacitors, and transformers play a critical part in today’s transceivers.In this book we will focus on the analysis and applications of such devices. In particular, we will demonstrate techniques for calculating the loss when such devices are fabricated in the vicinity of conductive substrates such as Silicon.