Sigma delta based receiver

A receiver based on embedding mixers inside a sigma delta modulator loop has been developed. In this way frequency conversion is obtained as part of the noise shaped analog-to-digital conversion. It is shown that the performance of the bandpass sigma delta loop can be predicted using a much simpler low-pass equivalent model. Using this result simple linear theory can be applied reducing the complexity of the analysis. Simulation of a discrete equivalent model shows agreement with predicted performance.