發(fā)布時間：2019-03-03 16:43

【摘要】：調(diào)頻連續(xù)波(FMCW)雷達與脈沖雷達相比具備以下優(yōu)點:高距離分辨力、不存在距離盲區(qū)、時寬帶寬積大、結(jié)構(gòu)簡單、體積小、成本低等,所以在汽車防撞雷達、交通監(jiān)測系統(tǒng)、微波探礦等方面具有廣泛應(yīng)用。但是,連續(xù)波體制雷達的收發(fā)信號泄漏問題,導致其作用距離有限,制約了它的進一步發(fā)展。針對FMCW雷達收發(fā)信號泄漏這一突出問題,本文采用數(shù)字式射頻對消的方法,降低FMCW雷達發(fā)射信號對接收通道的影響。本文的主要工作是設(shè)計一部步進頻雷達,包括鎖相源、發(fā)射鏈路、接收鏈路、數(shù)據(jù)采集部分,然后將射頻對消技術(shù)應(yīng)用于該步進頻雷達。本文首先介紹了該課題的研究背景、國內(nèi)外的研究情況以及研究意義,對連續(xù)波雷達存在的問題進行了簡單的分析,總結(jié)了當前用來減小發(fā)射機信號泄漏對接收機的影響的方法,其中著重介紹了本系統(tǒng)中用到的射頻對消技術(shù)的原理和實現(xiàn)方法。在此基礎(chǔ)上,設(shè)計了數(shù)字式射頻對消方案。數(shù)字式射頻對消過程分為采樣、計算和控制三個過程,通過對參考信號和泄漏信號的采樣分析,將其幅值和相位進行比對,進一步計算出控制矢量調(diào)制器所需要的控制電壓值,輸出至數(shù)模轉(zhuǎn)換器完成對矢量調(diào)制器的控制,形成與泄漏信號大小相等、相位相反的對消信號,在接收鏈路實現(xiàn)對消。經(jīng)過對硬件系統(tǒng)的調(diào)試和分析,完成了該對消實驗,實現(xiàn)了對射頻對消模塊的精確控制。實驗的測試結(jié)果為:從1.8GHz到2.2GHz的400MHz帶寬內(nèi),對消比達到30dB以上。最后總結(jié)了論文取得的成果和結(jié)論以及存在的問題。
[Abstract]:Compared with pulse radar, FM CW (FMCW) radar has the following advantages: high range resolution, no range blind area, large time-bandwidth product, simple structure, small volume, low cost, etc. So in automobile collision avoidance radar and traffic monitoring system, it has the advantages of high range resolution, no range blind area, large time-bandwidth product, simple structure, small volume and low cost, etc. Microwave prospecting is widely used. However, the leakage of received and received signals in CW radar restricts its further development due to its limited operating range. In this paper, the digital radio frequency cancellation method is used to reduce the influence of FMCW radar transmitted signal on the receiving channel in order to solve the problem of FMCW radar signal leakage. The main work of this paper is to design a step-frequency radar, including phase-locked source, transmitting link, receiving link, data acquisition part, and then apply radio frequency cancellation technology to this step-frequency radar. Firstly, this paper introduces the research background, the domestic and international research situation and the significance of the research, and simply analyzes the problems existing in CW radar. The current methods to reduce the influence of transmitter signal leakage on the receiver are summarized. The principle and implementation method of RF cancellation technology used in this system are emphatically introduced. On this basis, a digital RF cancellation scheme is designed. The digital RF cancellation process is divided into three processes: sampling, calculation and control. Through the sampling and analysis of the reference signal and the leakage signal, the amplitude and phase of the digital RF cancellation process are compared, and the control voltage value required for the control vector modulator is further calculated. Output to the digital-to-analog converter to complete the control of the vector modulator, the formation of the same size as the leakage signal, phase opposite cancellation signal, on the receiving link to achieve cancellation. After debugging and analyzing the hardware system, the cancellation experiment is completed, and the accurate control of RF cancellation module is realized. The experimental results are as follows: within the 400MHz bandwidth from 1.8GHz to 2.2GHz, the cancellation ratio is higher than 30dB. Finally, the paper summarizes the results and conclusions of the paper, as well as the existing problems.
【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TN958

【引證文獻】

相關(guān)碩士學位論文 前1條

1 朱澤坤;無人機通信干擾系統(tǒng)前端研究[D];電子科技大學;2018年

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本文編號：2433900