Frequency matched sub-sample feedforward modulation in amplitute level control loop

Abstract

An automatic level control (ALC) circuit includes an input configured to receive a radio frequency (RF) input signal, a level control circuit coupled to the input and configured to control a level of the RF input signal in response to a feedback signal, and an output coupled to the level control circuit and configured to output a level-controlled RF output signal. The ALC circuit further includes a feedback path coupled to the output and configured to sample the level-controlled RF output signal to determine an error detected in the level-controlled RF output signal, and to generate the feedback signal in accordance with the error. The ALC circuit still further includes a feedforward path coupled to the input and configured to emulate a frequency response in the feedback path and to adjust the error determined in the feedback path according to the emulated frequency response.