| Photonic phase shift technology which becomes one of the key technologies in microwave photonics can be used in optical beam forming network (OBFN), which is conducive to improve the system parameters such as accuracy, frequency stability and the output stability. Based on photonic phase shift technology, phased array radar (PAR) has the advantages of light weight, small size, high frequency, broadband and anti-interference. Deep space detection,satellite communication and smart antenna with photonic phase shift technology applied are considered of great value, which gradually forms new directions for future research. And photonic phase shift technology also can be used to achieve high frequency, broad bandwidth, large dynamic range, good frequency stability and optical fiber remote transmission in microwave photonic processing system. With the new type semiconductor material and the new photonic devices constantly springing up, photonic phase shift technology becomes the most important research branches for PAR research, which will present its core value in the future.Beam delay accuracy, frequency stability and the output stability in microwave photonic phase shifter (MWPPS) are studied through simulation and experimental analysis. We introduce new methods such as the phase compensation technology,spectral separation processing technology, RF signal long-distance fiber transmission. Experiments demonstrate the high precision beam delay, good frequency stability and the output stability in this method. In our work, the negative feedback based photonic phase shift method is first proposed for phase drift suppression, which implements RF signal long-distance optical fiber stable transmission. The above researches lay the foundation of optical-controlled phase shift technology in future communication. The main innovation points are as follows:1. In order to improve delay accuracy and the output stability, the linear chirp Fiber Bragg grating (LCFBG) is used as delay processing unit, and phase modulator (PM) is used as phase compensation unit. The lights with different wavelengths may be reflected in different points, which produces different optical path lengths and implements different phase shift. PM can compensate the delay jitter effect (GDR) produced by LCFBG, which improves the beam time delay accuracy and the system output stability.2. Considering that the modulation information is not carried by optical carrier, spectrum separation processing scheme with optical carrier delay processing is proposed. The phase shift information of carriers with different wavelengths converts to the output RF signal phase shift information. The experimental results show spectrum separation processing technology is simple and feasible with high beam delay precision and good output stability.3. With the effect of temperature and mechanical stress on long-distance optical fiber, RF signal is easy to get phase drift and output power jitter. The negative feedback photonic phase shift system is proposed to improve the beam accuracy, frequency stability and output stability. The phase drift is suppressed by the negative feedback network in center node, and the optical carrier phase is pre-compensated, which achieves the phase calibration and improves the delay precision, the frequency stability and the output stability.Finally, the experiment achieves RF signal optical fiber distance stability transmission based on negative feedback technology.4. The phase noise accumulation impacts the reliability and effectiveness for the communication system, which directly affects the communication quality and the accurate synchronization. The system frequency stability reflects the phase noise suppression level. Therefore, the frequency stability analysis is one of the key steps for long-distance fiber communication, whose evaluation methods on the frequency stability include phase noise spectrum method and Allan variance analysis method, which can evaluate the real-time operation of the system. |
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