Photonic analog-to-digital conversion with equivalent analog prefiltering by shaping sampling pulses.
We propose a photonic scheme to digitize RF signals with a programmable equivalent analog prefilter, where the filter impulse response is directly proportional to the time-reversed temporal shape of the sampling pulse and hence can be adjusted by shaping sampling pulses. The model of the proposed scheme is presented to prove its principle and derive its operation conditions. A four-channel scheme with program-controlled pre-filters is demonstrated experimentally, where bandpass filters with the phase shifts of 0°, 90°, 180°, and 270° are synthesized, respectively, by changing temporal shape of the sampling pulses. The experimental results agree well with the theoretical analysis, indicating the validity of the proposed scheme.
Feiran
F
Su
Guiling
G
Wu
Jianping
J
Chen