Studies On Photonic Rf Phase Shifter Of Microwave Photonic Signal Processing

The microwave photonic phase shifter is a key device in an optically controlled phased array system and is mainly used to form a beam network and perform direction scanning.In recent years,with the rapid development of phased array systems,higher-level performance requirements have been placed on its key device phase shifters,and the device characteristics of the electronic phase shifter have apparently been unable to meet the demand.Therefore,domestic and foreign research institutions and scholars are looking for an effective technical means to break through the bottleneck of electronic phase shifters—optical photology.Therefore,it is of great practical significance to study the microwave photonic phase shifter.The main contents of this article include:(1)Introducing the principles and technical characteristics of phased-array antennas,and then work on three photonic RF phase shifters based on optical true time delay(OTTD),vector sum,and heterodyne mixing.And technical solutions were analyzed and simulated to derive their respective advantages and disadvantages.(2)A phase-adjustable microwave photonic phase shifter based on DPMZM is proposed.The system structure and principle of the scheme are analyzed,and the feasibility of the scheme is verified through the VPI simulation platform.The result shows that the phase shift of the RF signal can be changed linearly by adjusting the bias voltage of the phase modulator(PM);This scheme is compared with the existing phase shifter scheme.The results show that the proposed scheme can still meet the requirements of the phase shifter in all aspects without using the optical filter.(3)A phase shifter scheme based on DPMZM frequency multiplication and phase adjustment is proposed.The system structure and principle of the scheme are analyzed and simulated.The result proves that this scheme have many advantages of convenient adjustment,large phase shift range,small output amplitude fluctuation etc.It also have the functions in frequency multiplication and amplitude control.