基于并联MZM的无滤波16倍频毫米波信号产生

Filterless Frequency 16-tupling Millimetre-wave Signal Generation Based on Parallel Mach-Zehnder Modulators

提出了一种基于并联马赫-曾德尔调制器的无滤波16倍频毫米波信号生成方案。该方案利用并联的马赫-曾德尔调制器和光移相器产生8阶光边带,通过光电探测器拍频得到16倍频毫米波信号。针对调制器消光比理想和不理想两种情况,理论推导了消光比分别为35 dB和100 dB下的抑制光载波及4阶光边带,产生8阶光边带信号,并通过仿真验证理论推导的正确性。根据仿真结果分析了调制指数偏移,电、光移相器相位偏移,光衰减器衰减值偏移等各种非理想参数对系统的影响,以及激光器线宽与接收功率的关系。结果表明:在方案产生的16倍频毫米波信号上调制2.5 Gbit/s的基带信号,系统传输距离5 km、10 km、15 km时损耗功率分别为0.35 dBm、0.55 dBm和2 dBm,传输损耗较小;线宽为10 MHz时接收功率为−22.6 dBm,线宽为20 MHz、30 MHz和40 MHz时功率损耗分别为0.1 dBm、0.25 dBm和0.6 dBm。

A scheme for generating 16-tupling millimeter wave signals is proposed,which uses parallel Mach-Zehnder modulators and optical attenuator without filters.In this scheme,the Mach-Zehnder modulator and optical phase shifter in parallel are used to generate the 8th-order optical sideband,and the 16-tupling millimeter wave signal is obtained through the beat frequency of photodetector.In view of ideal and non-ideal extinction ratio of modulator,when the extinction ratio is 35 dB and 100 dB respectively,the optical carrier and the fourth-order optical sideband are theoretically suppressed,and the eighth-order optical sideband signal is derived.The correctness of this deduction is verified by simulation.Furthermore,according to the simulation results,the influence of non-ideal conditions of various parameters,such as the shift of modulation index and optical attenuator attenuation value,the angle shift of electric phase shifter and optical phase shifter,on the system is analyzed.The 2.5 Gbit/s baseband signal is modulated on the 16-frequency millimeter wave signal generated by the scheme.When the transmission distance of the system is 5 km,10 km and 15 km,the loss power is 0.35 dBm,0.55 dBm and 2 dBm respectively,and the transmission loss is small.In addition,the relationship between laser linewidth and received power is analyzed.The received power is−22.6 dBm when the linewidth is 10 MHz,and the power losses are 0.1 dBm,0.25 dBm and 0.6 dBm when the linewidth is 20 MHz,30 MHz and 40 MHz,respectively.