SCHEME TO ALLEVIATE SIGNAL DEGRADATION CAUSED BY DIGITAL GAIN CONTROL LOOPS

摘要

An amplifier (10) comprises a digitally clocked automatic gain control loop (11, 12, 13, 14). A Pseudo random clock generator (14) generates the clock signals for the loop. The application introduces a scheme which reduces sidebands caused by digital gain control loops. The effect of gain control on a system can be seen as amplitude modulation on the signal whose amplitude is controlled. This amplitude modulation causes the same sidebands that are commonly seen with AM modulation. This invention introduces a novel method that alleviates AM sidebands for a digitally controlled gain control loop.