FMCW雷达物位计收发前端的设计

发布时间：2018-03-15 06:07

本文选题：调频连续雷达　切入点：ADF4159　出处：《电子科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着科技的发展,无论是工业生产还是军事的应用方面,雷达的距离探测已经成为了必不可少的技术手段。所以雷达性能的好坏直接影响到我们对目标距离的认知程度。通过对雷达相关理论的了解,不同信号类型的雷达与雷达的测距性能有着密不可分的关系。调频连续波雷达因其时宽带宽积大,极高的频率分辨率和理论上不存在距离盲区等优势,因此得到了广泛的应用。本文主要研究了调频连续波(FMCW)雷达的收发前端,主要包括频率源和接收机电路部分。主要的目的是设计出高性能的频率源,使其输出信号高线性度、频率稳定,有良好的相位噪声和杂散抑制,并对接收部分进行详细的理论分析和链路仿真。首先描述了设计调频连续波信号源常用的方法,详细的介绍了直接数字频率合成(DDS)技术与锁相环(PLL)技术的相关理论。简单叙述了三角波电压调制VCO与DDS和PLL相结合方案,分析其优劣。最终选择了利用PLL芯片ADF4159与压控振荡器(VCO)组成的锁相环电路产生线性调频连续波的方案。根据项目设计要求,确定相关的指标,给出设计框图,设计出电路原理图、PCB版图以及最后的实物并进行测试。以此设计出K波段线性调频信号源,中心频率24.5GHz,带宽1GHz。接收电路部分设计采用零中频接收机系统,同样根据项目要求和实际需要,确定相关指标,设计基本框图。其中利用HFSS设计基片集成波导(SIW)带通滤波器,对接收信号进行杂波滤除。本文将频率源的设计作为了重点,对方案进行创新,并非使用了常见的三角波电压信号调制压控振荡器和利用DDS与PLL相结合频率合成两种方法。而是利用新型PLL芯片ADF4159设计了频率合成器,该方法电路更加简单,免去了DDS部分,成本更低,频率可控程度高。本文最后对项目进行总结,并分析测试过程遇到的问题。
[Abstract]:With the development of science and technology, both industrial production and military applications, Radar range detection has become an essential technical means. Therefore, the performance of radar directly affects our understanding of target distance. Radar with different signal types is closely related to radar ranging performance. Because of the advantages of wide band wide product, high frequency resolution and the absence of range blind area in theory, FM CW radar has many advantages, such as large wide band product at that time, high frequency resolution, and no range blind area in theory. Therefore, it has been widely used. In this paper, the front-end of FM CW FMCW radar is studied, including frequency source and receiver circuit. The main purpose is to design high performance frequency source and make its output signal high linearity. Frequency stability, good phase noise and spurious suppression, and detailed theoretical analysis and link simulation of the receiver. Firstly, the common methods of designing FM CW signal source are described. The theory of direct digital frequency synthesizer (DDS) and phase-locked loop (PLL) is introduced in detail, and the scheme of combining triangle-wave voltage modulation (VCO) with DDS and PLL is briefly described. The advantages and disadvantages are analyzed. Finally, a phase locked loop circuit composed of PLL chip ADF4159 and VCO is selected to generate LFM continuous wave. According to the project design requirements, the relevant indexes are determined, and the design block diagram is given. The PCB layout and the final physical object are designed and tested. The K-band LFM signal source with a center frequency of 24.5 GHz and a bandwidth of 1 GHz is designed. The receiving circuit is designed with a zero-intermediate frequency receiver system. At the same time, according to the requirements of the project and the actual needs, the relevant indexes are determined, and the basic block diagram is designed. Among them, HFSS is used to design the substrate integrated waveguide siw) band-pass filter to filter the received signals. The design of the frequency source is taken as the emphasis in this paper. The scheme is innovated not by using the common voltage-controlled oscillator modulated by triangular wave voltage signal or by combining DDS with PLL frequency synthesizer, but by using a new PLL chip ADF4159 to design a frequency synthesizer. The circuit of this method is simpler. The DDS part is eliminated, the cost is lower and the frequency is controlled. Finally, the project is summarized and the problems encountered in the testing process are analyzed.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN957

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