Generation Of The High-performance Microwave Frequency Comb Based On DP-QPSK Modulation

Microwave frequency comb(MFC)can provide multi-frequency microwave signals,and has strong penetrating power,precise line spacing and wide frequency band range.Therefore,it is widely used in broadband wireless communication,radar guidance and remote sensing detection.The way to produce high-performance microwave frequency comb with wide bandwidth,good flatness and high power has been a hot topic for scholars all around the world.The microwave frequency comb is mainly produced by electrical and optical methods.The optical frequency comb technology based on optical method can overcome the electronic bottleneck problem,and has the advantage that the microwave method can not be compared by the electrical method,and the high frequency microwave frequency comb can be obtained.The comb line spacing is easy to tune and has attracted the attention of scholars.In this paper,a microwave frequency comb scheme based on dual-polarization quadrature phase shift keying(DP-QPSK)modulation loop is proposed and studied in depth.The specific research contents are as follows:Firstly,the working principle of DP-QPSK modulator is introduced,and its perfect theoretical model is established.The theoretical derivation of the working conditions of laser generating 2,3and 4 lines through DP-QPSK modulator and using optical communication The system design software Optisystem performs simulation,and respectively,the light is output through the DP-QPSK modulator to generate 2,3,and 4 spectral line outputs.Then the theoretical model of microwave frequency combing based on DP-QPSK modulation loop is established,and the scheme is simulated by Optisystem.The linewidth,input power,RF drive signal RF and photodetector response of the laser are studied.The effect of the degree on the microwave frequency comb signal.The research results show that adjusting the frequency of the RF drive signal RF can realize the tunability of the microwave frequency comb and improve the flexibility.Reasonable setting of the line width of the input optical signal and the responsiveness of the photodetector can improve the performance of the microwave frequency comb..Through optimization,the high-performance microwave frequency comb is realized under the working conditions of the DP-QPSK modulator generating 2,3 or 4 lines,the spectrum bandwidth is 300 GHz,the average power is 21.7d Bm,and the flatness is 0.1d B..The DP-QPSK modulation loop based on the proposed microwave frequency comb has the advantages of ultra-flat,wide bandwidth,high power,tunability,etc.,and is expected to be applied in channelized optical transmitters,high-speed wireless communications and satellite transponder systems.