Abstract:
One of the most significant methods in increasing the sampling rate of an analog-to-digital converter (ADC) system is to time-interleave multiple ADCs for alternate sampling. However, inevitable mismatch errors between different sampling channels could induce spurs in sampling results. In this paper, a correction algorithm for time errors between channels is proposed, which is compatible with ADCs working in the band-pass sampling mode for direct radio frequency sampling. The quantitative relationship between signal components and spur components in the frequency domain, which is determined by the time errors, is resorted in the proposed algorithm to calculate the parameters for error correction. Thus, it is possible to fix the zero-added sampling results from each channel. Simulation results show that the proposed algorithm could achieve favorable compensation for precisely-measured time errors even with large values. In addition, the effectiveness of the proposed algorithm is also verified in different scenarios including time-interleaved ADCs for base-band or band-pass sampling and with even or odd number channel counts.