冰层厚度探测雷达中频处理电路的设计与实现

发布时间：2018-04-30 23:16

本文选题：冰厚探测 + FMCW雷达　；参考：《电子科技大学》2016年硕士论文

【摘要】：海洋与人类的生活、经济、发展息息相关,但每年冬季海面结冰及海冰漂移又会带来巨大的损失与灾难。我国近海区域蕴藏着丰富的油气资源、渔业资源,海岸港口的贸易加快了沿海经济的发展,因此必须加强对海冰的监测和预报工作,以采取有效的冰情灾害防御措施。目前已有的探冰雷达系统存在探测效率低或薄冰分辨率低等缺点,无法得到海面薄冰的精确信息。本文提出了一种高精度的便捷海冰探测雷达系统,采用调频连续波(FMCW)雷达方案,设计小型化系统模块,可搭载无人机等其他飞行平台,续航能力强,可实现大范围快速精准探测海冰。本文在介绍了雷达系统的基础知识后侧重叙述了中频电路的分析和设计,为提高雷达系统性能,针对雷达距离分辨率和测距精度的指标要求,分析了中频电路设计中需要遵循的原则。中频电路系统主要包括中频信号处理、主控部分、压控振荡器(VCO)调制信号产生三大模块。其中中频信号处理模块包括前置放大器、自动增益(AGC)放大器、滤波器等部分;主控部分采用ALTERA公司的Cyclone III为核心处理雷达中频信号,多模块并行运行加快了系统工作效率,并添加了SD卡存储模块,用于记录大量的雷达探测数据,保证雷达大范围探测能力;调制信号产生模块对VCO的调频线性度具有重要影响,电路设计了特殊的校正方案以满足雷达系统距离分辨率的要求。除此之外,系统设计了高精度电源模块为VCO及其调制信号模块供电,保证FMCW探冰雷达发射信号的高精度要求。硬件系统的设计难点在于数模混合电路的隔离和保证信号的高信噪比。本设计通过优化布局布线,隔离数字芯片和模拟芯片来增加数模信号隔离度,设计高精密的电源,降低电源纹波噪声,并选用低噪声的芯片,从而充分降低系统内部噪声,提高了中频信号的信噪比。本文最终成果实现了高精度探冰雷达的中频电路硬件制作,并配合射频链路系统组成了FMCW探冰雷达系统。
[Abstract]:The ocean is closely related to the life, economy and development of human beings, but the sea ice and sea ice drift will bring huge losses and disasters every winter. There are abundant oil and gas resources, fishery resources and coastal port trade in the offshore area of our country, which accelerates the development of coastal economy. Therefore, it is necessary to strengthen the monitoring and forecasting of sea ice in order to take effective ice disaster prevention measures. The existing ice detection radar system has some shortcomings such as low detection efficiency or low ice resolution, which makes it impossible to obtain accurate information of thin ice on the sea surface. In this paper, a high precision and convenient sea ice detection radar system is proposed, which adopts FMCW radar scheme, designs miniaturized system modules, can carry other flight platforms such as UAVs, and has strong ability to continue. A wide range of rapid and accurate detection of sea ice can be achieved. After introducing the basic knowledge of radar system, this paper focuses on the analysis and design of intermediate frequency circuit. In order to improve the performance of radar system, the requirements of radar range resolution and ranging accuracy are discussed. The principles to be followed in the design of intermediate frequency circuits are analyzed. If circuit system mainly includes three modules: if signal processing, main control part and VCO modulation signal generation module. The frequency signal processing module includes preamplifier, AGC amplifier, filter and so on. The main control part uses Cyclone III of ALTERA Company as the core to process radar if signal. The SD card storage module is added to record a large amount of radar detection data to ensure the radar detection ability in a large range, and the modulation signal generation module has an important impact on the frequency modulation linearity of VCO. A special correction scheme is designed to meet the range resolution requirement of radar system. In addition, the high precision power supply module is designed to supply power to the VCO and its modulation signal module to ensure the high accuracy requirement of the FMCW ice detection radar signal. The design difficulty of hardware system lies in the isolation of digital-analog hybrid circuit and the guarantee of high signal-to-noise ratio (SNR). By optimizing layout and wiring, isolating digital chip and analog chip to increase the isolation degree of digital-analog signal, high precision power supply is designed to reduce the ripple noise of power supply, and the low noise chip is used to fully reduce the internal noise of the system. The signal-to-noise ratio of intermediate frequency signal is improved. In this paper, the hardware of if circuit of high precision ice detection radar is realized, and the FMCW ice detection radar system is made up of radio frequency link system.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN95;TH766

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