| The transmission and processing bandwidth of radio frequency signals in modern civil and military communications is getting higher and higher,which places higher requirements on the dynamic range,receiving sensitivity,and instantaneous bandwidth of radio frequency signal receivers.The application of microwave photonics to the transmission and processing of broadband radio frequency signals has become one of the important means.Microwave photonics-assisted channelization receiving technology has attracted wide attention due to its advantages of low loss,anti-electromagnetic interference and parallel processing.Existing microwave photon-assisted radio frequency signal channelization reception schemes have problems such as limited reception frequency bands and insufficient channelization efficiency.This paper will focus on the following research work: 1)photon-assisted multi-band microwave channelization technology;2)high-efficiency microwave photonic channelized receiving technology based on coherent detection.The main research work and contributions of this paper are as follows:1.In view of the limited reception frequency band of existing channelization schemes,a photon-assisted multi-band microwave signal channelization reception scheme is provided,in which the spectrum information is obtained by instantaneous spectrum analysis.Compared with the existing methods,the research and improvement scheme can realize the channelized reception of multi-band microwave signals when the spectrum information of the broadband signal is unknown.The research results show that the spectrum information is obtained through instantaneous spectrum analysis,and the coherent channelization process is further controlled to complete the reception of4 GHz linear chirp signals in different bands at 2-6GHz and 26-30 GHz,realize a 4-channel equivalent 28-channel receiver,reducing the number of optoelectronic devices.2.Aiming at the insufficient efficiency of coherent channelization,two high-efficiency microwave photonic coherent channelization schemes based on filter bank and polarization multiplexing are studied.A coherent channelized reception scheme with improved filter bank design is proposed.Through careful design of the relative frequency between the optical carrier and local oscillation required for coherent channelization,and the corresponding design of the final filter bank,broadband is achieved.The channelized reception of the signal,the simulation results proved the high channelization efficiency of channelizing the broadband signal into eight sub-channels under the premise of using only one optical carrier.A coherent channelized reception scheme using polarization multiplexing to improve the design of optical carrier and local oscillator is proposed,and the spectrum overlap caused by polarization multiplexing is used.Simulation results show that a pair of orthogonally polarized optical carriers and a pair of linearly polarized local oscillators can channel wideband signals into eight sub-channels,and at the same time reduce the number of local oscillators required for channelization,and After channelization,the signal-to-noise ratio only dropped by 3.33%. |
