光纤延迟线与多波束应用研究

发布时间：2018-02-27 17:10

本文关键词： 光控相控阵光实时延迟多波束噪声系数幅相误差　出处：《电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：传统相控阵天线技术已经很成熟,但是它受到渡越时间和孔径效应的影响,不能实现宽带、大角度扫描。光控相控阵天线利用实时延迟可以抵消孔径渡越时间,解决宽带和波束偏斜的问题。光控相控阵天线相还具有体积小、质量轻、损耗低、抗干扰等优点。多波束光控相控阵天线是通过光延迟来实现多波束的,它可以减小搜索间隔时间,利用光的分光和合光,将很容易实现波多束的形成。本文首先建立了光控相控阵天线的数学模型,并对其各个性能参数的理论公式进行了推导。理论上分析了在子阵上采用光实时延迟的结构中影响带宽和波束偏移的因素,并使用Matlab进行了仿真。其次建立了光电探测部分的模型并进行了噪声系数理论公式的推导。忽略频响,建立强度调制直接探测光链路的小信号模型,对其链路的增益以及噪声系数的公式进行了推导。然后对波束形成阵列建立了模型,利用光纤链路中所推导出的增益和噪声系数的公式推导了阵列的噪声系数公式。分析并仿真了光纤链路的衰减、阵元数以及前置放大器的增益对噪声系数的影响,8阵元存在探测饱和时噪声系数可以做到3.83dB。对存在链路噪声信号的16、32阵元的线阵进行仿真,链路的噪声主要影响副瓣电平的升高,当信噪比小于15dB时副瓣电平将上升很多。然后介绍了温度引起的延迟误差、阵元失效误差以及随机误差的来源及对波束的影响。其次对副瓣电平和波束偏斜的统计理论公式进行了推导,对随机幅相误差对波束的影响进行仿真分析,延迟误差主要影响波束的指向角,推导出了延迟误差均方值和指向角偏移的关系式。在0~3ps范围内,取100次指向角偏移仿真值的均方值画出的图和理论公式画出的曲线图一致。副瓣电平主要受幅度误差的影响,误差越大副瓣电平上升的越多。最后,介绍多波束形成的基本原理,设计了一种光控多波束形成的结构,每个波束都可以独立扫描。信号频率为10GHz,对于4波束16阵元的结构,幅相误差服从正态分布时,进行波束仿真。结果表明均方差为-5dB、-3dB时,指向角偏移为0.3°、0.6°;延迟误差均方差为2ps、3ps时,副瓣电平上升了1.97dB、2.64dB。
[Abstract]:The traditional phased array antenna technology has been very mature, but it is influenced by the transition time and aperture effect, cannot achieve broadband, large angle scanning. Real time delay can offset the aperture transit time using optically controlled phased array antenna, broadband and beam deflection. Optically phased array antenna which has the advantages of small volume, light weight loss. Low anti-jamming. The multi beam optical controlled phased array antenna is realized by multi beam optical delay, it can reduce the search time interval, and the use of photosynthetic light, will be easy to achieve the formation of wave beam. This paper established a mathematical model of optically controlled phased array antenna, and the theoretical formula all the performance parameters are deduced. The theoretical analysis of the influence factors of the bandwidth and beam deflection of structure light in real time delay in the sub array, and a simulation using Matlab. Its establishment The photoelectric detection part of the model is derived and the noise coefficient of theoretical formula. Ignoring the response, to establish the small signal model of intensity modulation direct detection optical link, the link gain and noise coefficient formulas were deduced. Then the beamforming array model, based on derived gain and noise coefficient in the optical fiber link is deduced noise coefficient formula of array. The analysis and Simulation of the attenuation of optical fiber links, effects of array element number and preamplifier gain for the noise coefficient of the 8 element of detecting the existence of saturation noise coefficient can reach 3.83dB. to 16,32 array line link noise signal array simulation. The main effect of noise link increased sidelobe level, when the signal-to-noise ratio is less than 15dB when the sidelobe level will rise a lot. And then introduces the delay error caused by temperature, element failure in error The source and the random error and the influence on the beam. Secondly the sidelobe level and beam deflection statistical equations are deduced, the random effect of amplitude phase errors on the beam simulation analysis, delay errors mainly influence the beam pointing angle, deduces the delay error mean square value and the relationship between the pointing angle offset type in the range of 0~3ps, 100 times to offset simulation values of the mean square value of the pictures and draw the graph theoretical formula. The sidelobe level is mainly affected by the influence of amplitude error, error is rising more chief lobe level. Finally, this paper introduces the basic principle of multi beam forming, design a a light beam forming structure, each beam can be independent of scanning. Signal frequency is 10GHz, the structure of the 4 beam 16 element array, the amplitude and phase error obeys normal distribution, beam simulation. The results show that the variance of -5dB, -3dB, The angle deviation is 0.3, 0.6, and the mean square of the delay error is 2PS. When 3ps, the sidelobe level rises 1.97dB, 2.64dB.

【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN821.8

【相似文献】