Correction of timing mismatches between two channels for photonic analog-to-digital converters

This paper presents a scheme to identify and compensate the timing mismatches between two channels for tipme interleaved photonic analog-to-digital converters(TIPADCs). The impact of electro-optic sampling is removed by preprocessing firstly. Then a calibration method combining chopping processing and a Hilbert transform is proposed to identify the timing mismatches, which can be further compensated by using various mature compensation algorithms. The principle of the proposed method is derived theoretically. The performance of the scheme is analyzed by simulation. The results show that the harmonic induced by timing mismatches can be suppressed by more than 30 dB using the proposed correction scheme.