Automatic Gain Control: Techniques and Architectures for RF Receivers

This book analyzes automatic gain control (AGC) loop circuits. The main objective of this book is to demonstrate AGC solutions in the environment of wireless receivers, mainly in wireless receivers with stringent constraints in settling-time and wide dynamic range, such as WLAN and Bluetooth receivers. Since feedforward AGCs present great advantages in this context, as an alternative to conventional feedback AGCs, this book includes a detailed study of feedforward AGCs design –at the level of basic AGC cells, as well as the system level, including their main characteristics and performance.

• Provides a complete review of automatic gain control loops, covering both feedback and feedforward approaches;
• Describes the complete design flow of the main blocks used in AGC circuits (PGAs/VGAs, peak detectors and control voltage generation circuits), considering low-voltage low-power restrictions;
• Includes real AGC architectures implemented as a general purpose digital feedforward CMOS AGC, a fully analogue feedforward AGC and a combined feedforward/feedback CMOS AGC