为了降低电光相位编码器功率消耗和解决内部M-Z调制器一致性要求高的问题, 利用2个偏置M-Z调制器构成了用于电光模数转换的2-bits电光相位编码器。理论分析了偏置M-Z调制器实现2-bits电光相位编码的方法、特点和性能。仿真结果验证了采用偏置M-Z调制器构成的2-bits相位编码方法可行性, 并实现了对1 GHz模拟电信号的采样速率12 GSa/s模数转换。分析和仿真结果表明, 采用该方法对调制器一致性要求低, 对输入信号功率要求低于0.32 W。分析结果表明, 调制器直流漂移不影响最低位量化结果, 引起最高位量化结果的判决模糊低于3.8%。

In order to decrease the power consumption of the electro-optical and resolve the high consistency with half-wave voltage of the inner Mach-Zehnder (M-Z) modulators in the phase encoder, using two biased M-Z modulators, a 2-bits electro-optical phase encoder for electro-optical analog-to-digital conversion (E-O ADC) was set up. The construction methods, features and performances of the 2-bits electro-optical phase encoder were analyzed theoretically. The simulation results verified the feasibility of the 2-bits electro-optical phase encoding method. The simulation experiments also fulfilled analog-to-digital conversion for signals at 1 GHz with sampling rate of 12 GS/s. The analysis and simulation results show that the proposed method has low requirement for the consistency of the modulators and the input signal power is lower than 0.32 W. The analysis results also show that the quantization of the least significant bit is immune from the modulators direct-current(DC) drift, while the decision uncertainty of the most significant bit influenced by the DC drift is lower than 3.8 %.