Compensated DELTA SIGMA controlled phase locked loop modulator

摘要

A DELTA SIGMA controlled phase locked loop modulation is used with limited oversampling factors while fulfilling the spectrum and/or phase noise requirements on the modulation in the phase locked loop. By filtering the quantization noise sufficiently then compensating for the distortion of the modulation at the input of the DELTA SIGMA modulator, the required oversampling factor of the DELTA SIGMA controlled phase locked loop modulators can be reduced without loss of performance. The distortion is mitigated by performing a compensation at the input to the DELTA SIGMA modulator. The noise reduction obtained by lowering the bandwidth of the phase locked loop can then be traded to reduce the oversampling factor.