Ka安防雷达中调频连续波频率源的设计和研究

发布时间：2018-04-15 12:39

本文选题：安防雷达 + FMCW频率源　；参考：《电子科技大学》2017年硕士论文

【摘要】：调频连续波(FMCW:Frequency Modulation Continuous Wave)雷达具有低发射功率、结构紧凑、高测距测相精度以及高抗有源干扰能力等优点,因此广泛应用于各种民用、军工领域。如何产生分高辨率、高线性度、高变频速度、低功耗的频率源,是当前频率合成技术的发展方向。本文主要工作内容如下:1.总结近年来FMCW雷达系统的国内外研究现状,分析FMCW雷达的硬件组成及测距测速信号处理原理。结合“Ka波段安防雷达系统”原理框图,阐述安防雷达整机的工作方式。根据FMCW雷达整机系统指标,反推出频率源的指标,研发安防雷达系统中的FMCW频率源。根据频率源的指标要求,结合目前最为成熟的两种频率合成技术,直接数字频率合成(DDS:Direct Digital Synthesis)和锁相环(PLL:Phase Lock Loop),本文最终选择使用“DDS与PLL两次混频结构”作为频率源设计的核心方案,研制一款X波段频率源。2.设计和测试频率源中各芯片模块的电路,主要包括了三个方面:(1)研发了一款基于HMC821和一款基于HMC834的锁相环电路,并分别对这两款锁相环电路进行了调试,计算频率控制字,将其编写成程序并写入到相应的寄存器。结合芯片基本工作原理,详细分析调试中所遇到的问题。对锁相环输出信号需要进行滤波处理,使其满足系统指标的要求。(2)研发了一款基于AD9910输出信号为调频连续波的DDS电路,详细计算频率控制字,设计芯片合理的外围供电和控制电路,并对其进行调试。选择合适的放大器芯片,设计合理的放大器外围供电、去耦滤波电路。(3)根据滤波器的指标和参数选择合适的滤波器,并将其应用于频率源电路中进行滤波。根据滤波器的理论和设计方法,设计一款多模阶梯阻抗谐振器(SIR:Step Impedance Resonator)的X波段微带滤波器,并对其进行测试,分析测试结果。3.在安防雷达系统各个功能模块调试完成之后,把频率源模块、射频收发机链路模块、中频自动增益控制模块、基带信号处理模块、电源模块进行整体装配并进行外场测试,分析实验数据。对比室外复杂环境和简单环境的条件下雷达的工作情况。分析各个模块的功耗,以及系统的总功耗。总结本文频率源的设计,提出还可以优化和研究的方向。
[Abstract]:FMCW: frequency Modulation Continuous Waveradar has the advantages of low transmitting power, compact structure, high ranging precision and high anti-active jamming ability, so it is widely used in various civil and military fields.How to produce frequency source with high resolution, high linearity, high frequency conversion speed and low power consumption is the development direction of frequency synthesis technology.The main work of this paper is as follows: 1.This paper summarizes the research status of FMCW radar system at home and abroad in recent years, analyzes the hardware composition of FMCW radar and the principle of signal processing for ranging and velocimetry.Combined with the principle block diagram of Ka band security radar system, the working mode of security radar whole machine is expounded.According to the index of FMCW radar whole machine system and the index of frequency source, the FMCW frequency source in security radar system is developed.According to the requirements of the frequency source, combined with the two most mature frequency synthesis technologies,Direct Digital Frequency synthesizer (DDS: direct Digital Synthesis) and PLL: phase Lock Loopine (PLL: phase). In this paper, we choose "DDS and PLL double mixing structure" as the core scheme of frequency source design, and develop an X-band frequency source. 2.The circuit of each chip module in the frequency source is designed and tested, including three aspects: 1) A phase locked loop circuit based on HMC821 and a phase locked loop circuit based on HMC834 is developed, and the two phase locked loop circuits are debugged to calculate the frequency control word.Write it into a program and write it to the corresponding register.Combined with the basic working principle of the chip, the problems encountered in debugging are analyzed in detail.The output signal of PLL needs to be filtered to meet the requirements of the system. (2) A DDS circuit based on frequency modulation continuous wave (FM) output signal of AD9910 is developed, and the frequency control word is calculated in detail.The reasonable peripheral power supply and control circuit are designed and debugged.Select the appropriate amplifier chip, design the reasonable amplifier peripheral power supply, decoupling filter circuit. Choose the appropriate filter according to the filter index and parameters, and apply it to the frequency source circuit to filter.According to the theory and design method of the filter, an X-band microstrip filter of Sir: step Impedance Resonator is designed and tested, and the test results are analyzed.After debugging each function module of the security radar system, the frequency source module, RF transceiver link module, if automatic gain control module, baseband signal processing module and power supply module are assembled and tested.Analyze the experimental data.The performance of radar in complex outdoor environment is compared with that in simple environment.The power consumption of each module and the total power consumption of the system are analyzed.The design of frequency source in this paper is summarized, and the direction of optimization and research is put forward.
【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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