Research On Phase Stablization Technology Of C-Band Microwave Over Fiber

Phase stabilization technology of microwave transportation is a new technology that uses the fiber to transmit the high phase stable microwave signal.As the microwave signal plays a more and more important role in basic scientific research,nobody deep space network.C-band microwave signal is widely commonly used in satellite frequency signal transmitting communication as it's downlink frequency band in 3.7GHz to 4.2GHz.But in the process of signal transportation,each part of the system components can make the remote receive signal phase jitter which affected by the external environment change.It impact the signal accuracy.Optical fiber with its low transmission loss,wide bandwidth,anti-electromagnetic interference,low cost,etc,are the main medium of microwave stable phase transportation system,at the same time,it become the main cause of signal phase jitter in the long distance signal transportation system,so before the optical fiber transmission,it needs real-time rapid phase compensation to make the signal phase of remote part constant.Phase detection and phase compensation in the center part is the key to the stabilization technology of microwave signal transportation.In this paper,the design scheme of microwave signal fiber-phase transmission system in recent years is analyzed and summarized.The performance and structure of the system are compared and evaluated,which leads to many problems of the existing scheme.Then,the influence of the main components of the optical fiber stable transmission system on the phase change of the signal transmission is discussed,and the description of the signal stability is given.A scheme of signal phase stable transmission system with subcarrier multiplexing and phase conjugate stationary phase is studied.The scheme is proved to be suitable for the stable transmission of signal.The composition of each part is described,the wide range phase compensation and high speed phase compensation is evaluated.The influence of temperature characteristics on the signal phase of the main components of the microwave signal fiber transmission system is analyzed.In the experimental scheme,the influence of the phase noise on the signal phase jitter is small and the optical fiber is still the main reason for the signal phase fluctuation.Then,a kind of microwave signal transmission scheme of loop electric mixing is improved.By detecting the long distance and long distance transmission of the signal,the phase fluctuation of the signal in the optical fiber transmission is obtained in the phase difference detection,and the control of the optical path compensation device is eliminated phase noise,so that the phase after the signal transmission is always stable.Finally,in the simulation to get the signal transmission after the phase has remained stable.