本文選題：線性調(diào)頻連續(xù)波雷達(dá) + 泄漏��； 參考：《電子科技大學(xué)》2014年碩士論文

【摘要】：調(diào)頻連續(xù)波(FMCW)雷達(dá)具有低成本和低功耗等特點(diǎn),在海軍戰(zhàn)術(shù)導(dǎo)航、雷達(dá)智能彈藥傳感器和汽車(chē)?yán)走_(dá)等不同領(lǐng)域獲得廣泛應(yīng)用。而且,具有單基結(jié)構(gòu)的雷達(dá),其發(fā)射機(jī)和接收機(jī)同時(shí)使用一個(gè)天線,這將使系統(tǒng)更緊湊。在設(shè)計(jì)單天線FMCW雷達(dá)的最大挑戰(zhàn)之一是在發(fā)射機(jī)和接收機(jī)之間有足夠的隔離度。在脈沖雷達(dá),這很容易通過(guò)時(shí)間選通來(lái)實(shí)現(xiàn)。在連續(xù)波雷達(dá),發(fā)射和接收是同時(shí)進(jìn)行的,而且要從環(huán)行器的泄漏信號(hào)和天線失配的反射信號(hào)中檢測(cè)皮瓦量級(jí)、甚至更低的目標(biāo)回波。這會(huì)導(dǎo)致兩個(gè)嚴(yán)重的問(wèn)題,其中一個(gè)問(wèn)題是發(fā)射機(jī)噪聲邊帶會(huì)淹沒(méi)有用的目標(biāo)。另外一個(gè)問(wèn)題是發(fā)射機(jī)功率泄漏到接收機(jī),降低了接收機(jī)的靈敏度。泄漏到接收機(jī)的發(fā)射功率的相位噪聲會(huì)落入同一頻帶的雷達(dá)視頻信號(hào),而且不能濾波出來(lái)。因而,常規(guī)的FMCW雷達(dá)的動(dòng)態(tài)范圍是有限的。本文圍繞發(fā)射泄漏進(jìn)行了分析和研究,包括泄漏原理和反射功率對(duì)消技術(shù)。在此基礎(chǔ)上,提出了一種改進(jìn)的方案,即自適應(yīng)對(duì)消系統(tǒng)。完成的具體工作如下:本文首先介紹了FMCW相關(guān)知識(shí),包括FMCW雷達(dá)的優(yōu)缺點(diǎn),FMCW雷達(dá)的一些應(yīng)用以及FMCW雷達(dá)的工作原理。在此基礎(chǔ)上,做了MATLAB仿真,包括連續(xù)信號(hào)和四個(gè)目標(biāo)回波。針對(duì)發(fā)射泄漏問(wèn)題,進(jìn)行了深入的分析,包括信號(hào)泄漏的途徑,天線反射原理和天線反射回波功率,并分析了泄漏噪聲對(duì)接收機(jī)性能的影響。其次分析了反射功率對(duì)消器(RPC)技術(shù)方案,包括模擬對(duì)消方案和數(shù)字對(duì)消方案。在此基礎(chǔ)上,分析了這兩種方案的優(yōu)缺點(diǎn)。同時(shí),對(duì)反射功率器的對(duì)消性能進(jìn)行了分析和研究,包括對(duì)消深度,對(duì)消寬帶和對(duì)消性能的評(píng)價(jià)。最后提出了改進(jìn)方案,采用自適應(yīng)對(duì)消結(jié)構(gòu)和LMS算法。在此基礎(chǔ)上,先介紹了LMS算法,從理論上研究了自適應(yīng)對(duì)消系統(tǒng)結(jié)構(gòu),并進(jìn)一步分析了系統(tǒng)的加權(quán)系數(shù)、輸出信干比(系統(tǒng)輸出的泄漏信號(hào)和噪聲的比值)以及信噪比。同時(shí),在MATLAB上對(duì)系統(tǒng)進(jìn)行仿真,包括只有泄漏信號(hào)的系統(tǒng)仿真,含有噪聲的系統(tǒng)仿真,含有目標(biāo)的系統(tǒng)仿真,含有兩個(gè)泄漏信號(hào)的系統(tǒng)仿真,本振信號(hào)含有噪聲的系統(tǒng)仿真和含有三個(gè)目標(biāo)信號(hào)的系統(tǒng)仿真。另外,研究了步長(zhǎng)對(duì)系統(tǒng)的影響,并做了仿真。
[Abstract]:FMCW (Frequency modulated continuous Wave) radar has been widely used in various fields such as naval tactical navigation radar intelligent ammunition sensor and automobile radar because of its low cost and low power consumption. Moreover, a radar with a single-base structure with a transmitter and receiver using an antenna will make the system more compact. One of the biggest challenges in designing a single antenna FMCW radar is enough isolation between the transmitter and the receiver. In pulsed radar, this is easily achieved by time switching. In continuous-wave radar, the transmitter and receiver are simultaneously transmitted and received, and the Piwa order of magnitude or even lower target echo is detected from the leaky signal of the circulator and the mismatched reflection signal of the antenna. This can lead to two serious problems, one of which is that the transmitter noise sideband submerges useful targets. Another problem is the transmitter power leakage to the receiver, reducing the sensitivity of the receiver. The phase noise leakage to the receiver will fall into the same frequency band radar video signal and can not be filtered out. Therefore, the dynamic range of conventional FMCW radar is limited. This paper focuses on the analysis and research of emission leakage, including leakage principle and reflection power cancellation technology. On this basis, an improved scheme, adaptive cancellation system, is proposed. The main contents of this paper are as follows: firstly, this paper introduces the related knowledge of FMCW, including the advantages and disadvantages of FMCW radar and some applications of FMCW radar, as well as the working principle of FMCW radar. On this basis, MATLAB simulation is done, including continuous signal and four target echo. Aiming at the problem of emission leakage, this paper makes a deep analysis, including the channel of signal leakage, the principle of antenna reflection and the reflection power of antenna, and analyzes the influence of leakage noise on the performance of receiver. Secondly, the technical scheme of reflective power canceller (RPC), including analog cancellation scheme and digital cancellation scheme, is analyzed. On this basis, the advantages and disadvantages of the two schemes are analyzed. At the same time, the cancellation performance of the reflector is analyzed and studied, including the cancellation depth, wideband cancellation and cancellation performance evaluation. Finally, an improved scheme is proposed, which adopts adaptive cancellation structure and LMS algorithm. On this basis, the LMS algorithm is introduced, and the structure of the adaptive cancellation system is studied theoretically. The weighting coefficient, the output signal-to-interference ratio (the ratio of leakage signal to noise) and the signal-to-noise ratio (SNR) of the system are further analyzed. At the same time, the simulation of the system is carried out on MATLAB, including the system simulation of only leakage signal, the system simulation with noise, the system simulation with target, the system simulation with two leakage signals. System simulation of local oscillator signal with noise and system simulation with three target signals. In addition, the effect of step size on the system is studied and simulated.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：TN957.51

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

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本文編號(hào)：1945826