X波段连续波雷达收发前端的设计与实现-电磁场与微波技术专业论文.docxVIP

万方数据 万方数据 摘 要 摘 要 在现代化战争中，雷达已经成为了侦察探测目标不可缺少的技术手段。所以 雷达性能的好坏严重影响着对侦察目标的认识，判断。由雷达信号的相关理论可 知，雷达性能与信号参数之间的选取有着巨大密切的关系。线性调频连续波雷达 发射的线性调频信号可以有效的增加信号带宽，实现极高的频率分辨力，以及不 存在距离盲区等优势，得到了广泛的应用。 首先本文通过 DDS 直接产生线性调频信号，通过十六次倍频和上变频技术成 功产生了 X 波段线性调频雷达发射信号，其带宽 300MHz，跳频时间达到 8ns，频 率分辨力达到 300Hz。阐述了应用 DDS 芯片 AD9858 产生线性调频信号的原理， 过程以及设计方法。再次本文对收发机原理，以及相关结构做了简要的阐述，设 计了零中频接收机系统，并对相关的指标进行核算，给出设计框图，以及 PCB 版 图，腔体设计等。接着在整个系统调试中，设计调试出特性滤波器，调试解决发 射接收信号的平坦度以及出现的杂散等。最后简单介绍了锁相环技术（PLL）的工 作原理，相位噪声以及杂散控制。应用芯片 ADF410X 系列产生了 DDS 所需要的 时钟信号和上变频所需的本振信号，其相位噪声达到技术指标要求。 在文章结尾，对本项目进行了总结，分析解决了调试过程中遇到的问题，使 系统达到技术指标要求，正常工作，最后完成 X 波段侦察雷达收发前端一部现已 交付使用。 关键词：收发前端 连续波雷达 X 波段 线性调频信号 I ABSTRACT ABSTRACT In modern war, the radar has become the indispensable technical to investigate and detection object. So the performance of the ray of good seriously affects the understanding of target detection, judgment. By the theory of radar signal can be known, the radar performance has huge close relationship between the signal parameters. Linear frequency modulated continuous wave radar transmitter linear FM signal which can effectively increase the signal bandwidth, and achieve high frequency resolution, and there is no distance blind spots and other advantages.So the LFM-CW radar has been widely used. First in this paper, linear frequency modulation signal is directly produced by DDS and on this basis, through a multiplier and inverter technology successfully generated X-band chirp signal bandwidth of 300MHz, stepping time of 8ns, frequency resolution achieve 300Hz. This article mainly introduced the application of DDS chip AD9858 produced the principle of linear FM signal, process and methods, Again, the transceiver principle, structure and related briefly in this paper, and designed a zero-IF receiver system accounting related indicators, given the design diagram and PCB layout, cavity design and so on. Then at the commissioning of the entire system ，we design and debugging features filters, solve the flatness of the transmittin