Effects of superimposed signal on microwave photonic filter performance

The microwave photonic filter combines the advantages of microwave and photonic researches. Yet the application of the microwave photonic filter is restricted by its flaws of nonlinear distortion and dispersion. In this experiment, we superimposed two signals with different phases. And we modulated them with intensity modulator and delay unit to make their peak values evenly distributed, also with their PAPR reduced, in order to suppress the nonlinear distortion of the modulating system; meanwhile, we regulated the intensity of the dispersion for the purpose of locating the correlations between linkage dispersion and nonlinear distortion. The experiment finally achieved good results in limiting nonlinear distortion and dispersion.