基于FMCW的探冰雷达数字中频系统的设计与实现

发布时间：2018-03-20 22:54

本文选题：冰厚测量　切入点：FMCW探冰雷达　出处：《电子科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：目前对于海冰的研究主要集中在对南北极冰盖的研究,通过卫星遥感的方法研究冰盖的分布。但是这些方法效率低、分辨率低,无法快速得到薄冰的相关信息。本文研究内容为FMCW冰层厚度探测雷达,设计一套小型化、续航能力突出、可以突破直接测冰的限制的雷达系统,通过无人机探测到人类不能涉足的冰层。雷达系统分为射频部分和中频部分,射频部分主要进行射频收发链路的设计,本文主要是对中频部分进行设计和实现。首先介绍了 FMCW探冰雷达的理论基础,包括调制方式和雷达的系统结构,对影响雷达分辨率和精度的因素进行了分析;确定了 FMCW的扫频带宽,调制方式的选择;VCO非线性度的理论分析,讨其对设计指标的影响,为下一阶段的硬件设计和实现做好准备。然后进行中频部分硬件设计,首先设计VCO的调制信号产生电路并进行非线性度校正,然后对中频信号调理电路和采集存储部分进行了设计和实现。调理电路主要是对中频信号进行低噪声放大、AGC放大、滤除VCO调制信号的调幅影响、滤除高频噪声对中频信号的影响。处理后的中频信号经过采集存储电路,存储于SD卡。软件部分主要是对采集存储部分的STM32进行片上外设和外设的配置,通过对ADC、DMA、FSMC、SDIO等片上外设的配置,结合应用层软件的设计并挂载文件系统,完成软件部分的设计。设计出的采集存储部分进行PCB设计,并测试其电源性能、采集结果测试;测试VCO调谐电压;最后将数字中频系统和射频系统进行联调测试,测得实验用冰块数据并进行FFT分析,供后期进行算法分析。设计的关键在于VCO的非线性校正,VCO的线性度差会导致整个系统不能进行测量。本文最终成果是对FMCW探冰雷达的中频部分进行设计实现,能够将射频部分处理的中频信号进行采集和存储。
[Abstract]:At present, the research on sea ice is mainly focused on the study of the polar ice sheet, and the distribution of the ice sheet is studied by satellite remote sensing. However, these methods are inefficient and have low resolution. The research content of this paper is FMCW ice thickness detection radar, designed a set of radar system with miniaturization, outstanding endurance, and can break through the limit of direct ice detection. The radar system is divided into radio frequency part and intermediate frequency part. The radio frequency part mainly carries on the design of radio frequency transceiver link. In this paper, the if part is designed and implemented. Firstly, the theoretical basis of FMCW ice detection radar is introduced, including modulation mode and radar system structure, and the factors that affect the resolution and precision of radar are analyzed. This paper determines the frequency sweep bandwidth and modulation mode of FMCW, analyzes the nonlinear degree of FMCW, discusses its influence on the design index, and prepares for the next stage of hardware design and implementation. Then, the hardware design of intermediate frequency part is carried out. First, the modulation signal generation circuit of VCO is designed and the nonlinearity is corrected, then the if signal conditioning circuit and the acquisition and storage part are designed and implemented. The amplitude modulation effect of VCO modulation signal and the influence of high frequency noise on if signal are filtered. After processing, the if signal is collected and stored. The software is mainly used to configure the peripheral devices and peripherals of the STM32 of the acquisition and storage parts. Through the configuration of the peripheral devices such as the ADC-DMA-FSMC / SDIO and so on, the paper combines the design of the application layer software and mounts the file system. Complete the software design. The design of the acquisition and storage part of the PCB design, and test its power performance, acquisition test results; test the VCO tuning voltage; finally, the digital if system and radio frequency system are combined to test, The ice cube data were measured and analyzed by FFT. The key point of the design is that the linearity difference of VCO can not be measured. The final result of this paper is to design and implement the if part of FMCW ice detection radar. The if signal processed by RF part can be collected and stored.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN959

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