Estimation and compensation methods of time delay and phase offset in hybrid filter bank DACs

Abstract

This Letter studies the non-ideal analogue filters performance, time delay and phase offset in hybrid filter bank (HFB) DACs. After compensating the non-ideal filters performance using a digital signal, a linear phase function containing time delay and phase was deduced based on the auto-power spectrum of the HFB DAC output in the overlapped frequency band. ‘Three-point’ method was used to simultaneously estimate these two errors by unwrapping the phase affected the principal value interval of the inverse trigonometric function. These two errors were compensated by the digital pre-distortion technique. Finally, simulation results were provided to verify the effectiveness of this proposed method.