基于色散光纤棱镜的光控波束形成及温度特性研究
发布时间：2018-10-10 07:33
【摘要】：随着科学技术的迅猛发展,为了满足人们对于雷达技术要求的不断提升,有关相控阵天线的相关技术应运而生。相控阵天线可以通过对系统中各不同的天线阵元之间微波信号的相位延时的变化情况进行相应的控制,从而实现波束的形成与扫描工作,因而其拥有着无物理运动转向、波束指向范围精准并且灵活度较高的优点。然而目前在宽带相控阵天线中通常会使用电移相器控制微波信号的相移,但是传统的微波移相器会使信号的瞬时带宽受到孔径效应的限制,从而对相控阵天线系统的性能产生影响,因此利用实时延技术实现相控阵天线系统就成为解决这一难题的有效手段之一。利用微波光子实时延技术实现的光控相控阵天线与传统的相控阵天线系统相比其信号损耗较低,工作带宽范围大,生存能力强,保密性能也更优秀,因此基于微波光子技术的可调光延时线已经成为相关问题研究的热点方向。目前已被国外广泛报道的各类光延时线结构主要由有普通光纤延时结构、色散光纤真延时结构、微环滤波器延时结构、空间光栅延时结构以及利用布拉格光栅和啁啾光栅等光纤光栅的延时结构,而国内的相关研究则起步较晚,且尚在发展阶段。因此本文在此基础之上,设计了一种基于色散光纤棱镜的光相控阵天线波束形成系统,并详细介绍了其系统结构及工作原理,同时对基于色散光纤棱镜的光延时线温度特性进行了理论介绍与分析。这一结构的光相控阵天线对于光纤切割精度的要求较低,同时系统中采用的光学元件及各类器件的数目较少,避免了光开关的使用,能够在显著降低成本的同时极大的提升系统工作精度和工作性能。为了对基于色散光纤棱镜的光相控阵天线系统波束成系统的性能与可行性进行具体分析,我们对系统的各项参数进行了计算并使用了Optisystem软件对系统链路进行仿真设计,同时通过使用MATLAB软件对系统的波束指向角度进行计算,验证了根据相应的系统参数设计,Ka频段下的基于色散光纤棱镜的光相控阵天线系统可以±30°的波束指向范围内稳定工作,同时得到了由于1nm的波长抖动所引起的波束指向角度偏移大约为1.92°。最后在实验部分,我们简单介绍了在实验中使用的矢量网络分析仪的工作原理以及系统误差校准的相关知识。并通过使用矢量网络分析仪对不同光纤信道中传输信号的相位-频率曲线进行测试,并进行了相关计算,从而对温度变化对于光相控阵天线系统波束指向合成的影响进行了实验研究,最终可以得到由于1℃的温度变化所引起的不同通道间延时差值最大为0.63ps,并且在Ka频段下可以通过调相设置一个中心温度使基于色散光纤棱镜的光相控阵天线系统可以在波束指向偏移±3.5°的允许范围内,在±7.5℃的温度范围内正常工作。
[Abstract]:With the rapid development of science and technology, in order to meet the requirements of radar technology, the related technology of phased array antenna came into being. The phased array antenna can control the change of phase delay of microwave signal between different antenna elements in the system, thus the beamforming and scanning can be realized, so that the antenna has no physical motion steering. The advantages of accurate beam pointing range and high flexibility. However, in the wideband phased array antenna, the electric phase shifter is usually used to control the phase shift of the microwave signal, but the traditional microwave phase shifter will limit the instantaneous bandwidth of the signal by the aperture effect. As a result, the performance of phased array antenna system is affected, so the realization of phased array antenna system using real-time continuation technology has become one of the effective methods to solve this problem. Compared with the traditional phased array antenna system, the optical phased array antenna realized by microwave photonic real-time continuation technology has lower signal loss, wider working bandwidth, stronger survivability and better security performance. Therefore, the tunable optical delay line based on microwave photon technology has become a hot research topic. At present, all kinds of optical delay line structures that have been widely reported abroad are mainly composed of common fiber delay structure, dispersion fiber true delay structure and microloop filter delay structure. The space grating delay structure and the fiber Bragg grating and chirped grating delay structure are used, but the related research in China is late and still in the stage of development. On the basis of this, a kind of optical phased array antenna beamforming system based on dispersive fiber prism is designed, and its system structure and working principle are introduced in detail. At the same time, the temperature characteristics of optical delay line based on dispersive fiber prism are introduced and analyzed theoretically. The optical phased array antenna with this structure requires less precision of optical fiber cutting, and the number of optical elements and all kinds of devices used in the system is less, thus avoiding the use of optical switches. It can greatly improve the system working precision and performance while significantly reducing the cost. In order to analyze the performance and feasibility of the beamforming system of optical phased array antenna system based on dispersive fiber prism, we calculate the parameters of the system and use Optisystem software to simulate the system link. At the same time, by using MATLAB software to calculate the beam-pointing angle of the system, it is verified that the optical phased array antenna system based on dispersive fiber prism can work stably in 卤30 掳beam-pointing range according to the corresponding system parameters. At the same time, the beam-pointing angle offset caused by the wavelength jitter of 1nm is about 1.92 掳. Finally, in the experimental part, we briefly introduce the working principle of the vector network analyzer used in the experiment and the related knowledge of system error calibration. The phase-frequency curves of the transmitted signals in different fiber channels are tested by using a vector network analyzer, and the correlation calculation is carried out. The effect of temperature change on beam direction synthesis of optical phased array antenna system is studied experimentally. Finally, the maximum delay difference between different channels caused by temperature variation at 1 鈩，
本文编号：2261173
[Abstract]:With the rapid development of science and technology, in order to meet the requirements of radar technology, the related technology of phased array antenna came into being. The phased array antenna can control the change of phase delay of microwave signal between different antenna elements in the system, thus the beamforming and scanning can be realized, so that the antenna has no physical motion steering. The advantages of accurate beam pointing range and high flexibility. However, in the wideband phased array antenna, the electric phase shifter is usually used to control the phase shift of the microwave signal, but the traditional microwave phase shifter will limit the instantaneous bandwidth of the signal by the aperture effect. As a result, the performance of phased array antenna system is affected, so the realization of phased array antenna system using real-time continuation technology has become one of the effective methods to solve this problem. Compared with the traditional phased array antenna system, the optical phased array antenna realized by microwave photonic real-time continuation technology has lower signal loss, wider working bandwidth, stronger survivability and better security performance. Therefore, the tunable optical delay line based on microwave photon technology has become a hot research topic. At present, all kinds of optical delay line structures that have been widely reported abroad are mainly composed of common fiber delay structure, dispersion fiber true delay structure and microloop filter delay structure. The space grating delay structure and the fiber Bragg grating and chirped grating delay structure are used, but the related research in China is late and still in the stage of development. On the basis of this, a kind of optical phased array antenna beamforming system based on dispersive fiber prism is designed, and its system structure and working principle are introduced in detail. At the same time, the temperature characteristics of optical delay line based on dispersive fiber prism are introduced and analyzed theoretically. The optical phased array antenna with this structure requires less precision of optical fiber cutting, and the number of optical elements and all kinds of devices used in the system is less, thus avoiding the use of optical switches. It can greatly improve the system working precision and performance while significantly reducing the cost. In order to analyze the performance and feasibility of the beamforming system of optical phased array antenna system based on dispersive fiber prism, we calculate the parameters of the system and use Optisystem software to simulate the system link. At the same time, by using MATLAB software to calculate the beam-pointing angle of the system, it is verified that the optical phased array antenna system based on dispersive fiber prism can work stably in 卤30 掳beam-pointing range according to the corresponding system parameters. At the same time, the beam-pointing angle offset caused by the wavelength jitter of 1nm is about 1.92 掳. Finally, in the experimental part, we briefly introduce the working principle of the vector network analyzer used in the experiment and the related knowledge of system error calibration. The phase-frequency curves of the transmitted signals in different fiber channels are tested by using a vector network analyzer, and the correlation calculation is carried out. The effect of temperature change on beam direction synthesis of optical phased array antenna system is studied experimentally. Finally, the maximum delay difference between different channels caused by temperature variation at 1 鈩，
本文编号：2261173
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