激光雷达截面测量系统中有源滤波器稳定技术研究

发布时间：2018-05-20 17:16

本文选题：激光雷达截面 + 有源滤波器　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：激光雷达是激光技术和雷达技术相结合的产物,其分辨率高,抗干扰能力强,并且可以三维成像,被广泛用于测距、测角、精确跟踪、引信传感、飞船导航、气象测量等方面,在民用和军事上都具有巨大的应用价值。本文首先分析了激光雷达截面的物理意义,给出了目标激光雷达截面的计算、测量原理与方法,从激光雷达截面的理论定义出发,推导出普遍适用于各类激光测量系统和各种散射特性目标的基本测量方程,该方程利用激光雷达截面表征目标的激光散射特性。为了更精确地获得激光雷达截面的测量数据,系统采用空间滤波方法以提高接收系统的信噪比,排除背景和噪声的干扰。然后本文研究了用于激光雷达截面测量系统的有源滤波器的设计,并论述了双二次滤波电路的相关理论,重点讨论了双二次有源带通滤波电路的设计方法。随后讨论了双二次滤波电路中RC元件和集成运算放大器增益变化的灵敏度,并求解出符合要求的双二次有源带通滤波电路参数。根据求解出的电路参数,对双二次有源带通滤波器进行仿真。最后本文提出了双二次有源带通滤波器中心频率因受温度影响发生漂移的稳定策略及其原理,对比介绍了包括结型场效应管、模拟开关和电阻网络及数字电位器在内的控制方法,着重介绍了基于数字电位器AD8400的程控增益系统,并利用程控增益放大器设计和实现中心频率可实时自动调节的带通滤波器,实验结果表明本文设计的滤波器通带宽度达到22Hz,中心频率可实时自动调节,满足实际需要。
[Abstract]:Lidar is the product of the combination of laser technology and radar technology. It has high resolution, strong anti-jamming ability, and can be used in 3D imaging. It is widely used in ranging, angle measurement, accurate tracking, fuze sensing, spacecraft navigation, meteorological measurement, etc. It has great application value in both civilian and military fields. In this paper, the physical meaning of laser radar cross section (LRCS) is analyzed, and the calculation, measurement principle and method of LRCS are given. The basic measurement equations for various laser measurement systems and targets with various scattering characteristics are derived. The laser scattering characteristics of the target are characterized by the laser radar cross section (LRCS). In order to obtain the measurement data of lidar cross section more accurately, the spatial filtering method is used to improve the signal-to-noise ratio of the receiving system and to eliminate the interference of background and noise. Then, the design of active filter used in lidar cross section measurement system is studied, and the theory of double secondary filter circuit is discussed, and the design method of double secondary active band-pass filter circuit is discussed emphatically. Then the sensitivity of the gain variation of RC components and integrated operational amplifiers in biquadratic filter circuit is discussed and the parameters of dual-quadratic active band-pass filter circuit are obtained. According to the calculated circuit parameters, the double secondary active band-pass filter is simulated. Finally, this paper presents a stability strategy and its principle for the drift of the center frequency of the dual-secondary active band-pass filter due to temperature, and compares and introduces the junction type field effect transistor (FET). The control methods of analog switch, resistance network and digital potentiometer are introduced in this paper. The program control gain system based on digital potentiometer (AD8400) is introduced, and the band pass filter which can adjust the center frequency in real time is designed and realized by using the program control gain amplifier. The experimental results show that the passband width of the filter designed in this paper can reach 22Hz and the center frequency can be automatically adjusted in real time to meet the practical needs.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN958.98

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