A broadband digitizer is proposed and experimentally demonstrated based on photonic time stretch (PTS). In this scheme, a complementary single-sideband modulation architecture in combination with successive digital difference operation and phase compensation are employed to simultaneously eliminate dispersion-induced power fading problem, remove dynamic pulse envelope, suppress modulation nonlinearity impairment and maintain broadband waveform fidelity. In the proof-of-concept experiment, a PTS preprocessor with a stretch factor of 8.77 and a time window of 1.8 ns is realized, where the maximum power degradation in the frequency range up to 25 GHz is 5 dB. By using this preprocessor, single-tone microwave signals in the frequency range of 2 to 25 GHz are digitized with effective number of bits larger than 3.4 bits. For single-tone input microwave signals at 12 and 15 GHz, the 2 ^nd -order harmonic suppression ratios are enhanced by 11.51 and 16.86 dB, respectively. For a two-tone microwave signal at 8 and 10 GHz, the synthetic waveform fidelity after time stretch is maintained by carrying out phase compensation.

中文翻译：

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基于光子时间展宽的宽带瞬态波形数字化仪

提出了一种宽带数字转换器，并基于光子时间拉伸（PTS）进行了实验演示。在该方案中，采用了互补的单边带调制架构，并结合了连续的数字差分操作和相位补偿，以同时消除色散引起的功率衰减问题，消除动态脉冲包络，抑制调制非线性损伤并保持宽带波形保真度。在概念验证实验中，实现了具有8.77的拉伸因子和1.8 ns的时间窗的PTS预处理器，其中，在高达25 GHz的频率范围内，最大功率降级为5 dB。通过使用该预处理器，可以以有效位数大于3.4位的方式数字化2至25 GHz频率范围内的单音微波信号。 ^第二 阶谐波抑制比通过11.51和16.86分贝分别增强。对于8和10 GHz的双音微波信号，通过执行相位补偿可以保持时间拉伸后的合成波形保真度。