Adaptive gain and/or phase adjustment control system and method

Abstract

An adaptive gain and/or phase control system adapts the gain and/or phase adjustment resolution to provide improved performance. For example, the adaptive gain and/or phase control system can dynamically adjust the adjustment resolution for gain and/or phase adjustments as a function of the error signal(s). In response to a large error signal(s) (far from the null), the adaptive gain/or phase control system decreases the adjustment resolution, resulting in a faster convergence rate. In a feed forward distortion reduction system, decreasing the adjustment resolution improves the transient response of the amplifier (for example, given any set of operating conditions, how quickly the amplifier responds to a changing input). As phase or gain adjustments are made to approach the null, the error signal reduces, and the adaptive distortion reduction system increases the adjustment resolution. By increasing the adjustment resolution as the error signal approaches the null, finer phase or gain adjustments can be made which further reduce the error signal. For example, in a feed forward distortion reduction system, such a scheme prevents the error signal from repeatedly jumping over the null due to limited resolution without sacrificing the transient response of the amplifier.