Abstract:
Time-interleaved architecture is the mainstream architecture of high-speed analog-to-digital converter(ADC). The strays of frequency domain will be introduced due to the inconsistency of amplitude-frequency characteristic and sampling time mismatch between sub-ADCs, which will seriously affect the performance of ADC. To solve this problem, a method of frequency spectrum correction is proposed in this paper. All the signals of the correction frequency sequence in the working band of the high-speed ADC are generated and injected by the standard signal source. The frequency spectra of each sub-ADC of all signals are calculated to obtain the correction coefficients of each spectrum of each sub-ADC corresponding to all signals of the correction frequency sequence. The final correction coefficient is obtained by taking the mean value. The data from each sub-ADC is first subjected to spectrum calculation, then corrected using the correction coefficient during operation. After that, the spectra obtained from all sub-ADC corrections are combined for further processing, which enables the acquisition of the spectrum of the time-interleave architecture ADC. The use of the correction coefficient is integrated into the spectrum analysis calculation, and the corrected sampling data is obtained by Fourier inversion. The simulation results show that the proposed method is effective for single frequency signal, simultaneous multi-signal and wideband signal.