【作者】 袁雪林；

【导师】 袁乃昌；

【作者基本信息】 国防科学技术大学 ， 电子科学与技术， 2008， 博士

【摘要】 超宽带技术以其巨大的发展潜力受到了各国的广泛关注,在通信和雷达领域取得了飞速的发展,引领着一场技术革命。超宽带冲激雷达作为超宽带雷达中的一员,其特点是:发射和接收无载波短脉冲,从回波信号中获取目标距离、速度和精细结构信息。超宽带冲激雷达具有很大的工作带宽,相对于常规的窄带雷达,具有许多的潜在优势和巨大的军事应用价值。虽然近距离的超宽带冲激雷达因为技术难度较小而发展较为迅速,各国都有一些产品面世,但对于中远程超宽带冲激雷达却鲜有报道,其理论和关键技术都有待进一步研究。“十五”期间,实验室研制了较为完备的中远程超宽带冲激雷达实验样机系统,其最大作用距离超过5公里,达到了国际先进水平,并做了大量的理论和实验研究。本文是在此基础上的后续研究和探讨,其重点在于中远程超宽带冲激雷达对动目标检测及跟踪的理论与关键技术的研究,主要内容包括:首先对中远程超宽带冲激雷达脉冲源进行了深入的研究。详细分析了脉冲源稳定度指标的影响因素,设计出基于雪崩三极管的全固态高稳定度脉冲源单元。通过电路合成和空间合成两种方式进行脉冲源单元的功率和重复频率的相干合成,研制出高功率、高重频脉冲源,为实现超宽带冲激雷达的中远程目标探测提供了前提条件。然后对超宽带冲激雷达动目标检测方法进行了研究,目标回波识别检测是超宽带冲激雷达动目标检测的合适方法。分析了超宽带冲激雷达动目标时域多普勒测速原理,实现目标速度测量的关键在于目标回波的有效积累,文中提出了三种动目标回波积累方法:回波达到时间预估法、分段积累法和回波到达时间预估的分段积累法。进行了大量的超宽带冲激雷达动目标时域多普勒测速仿真研究,三种回波积累方法在适用范围内都能有效目标回波,提高信噪比和测速精度。同时,提出了一种新的动目标测速方法—时域波形对消法,将回波到达时差转化为电压幅度值,对其量化测量,从而反推出回波时差和目标速度。对时域天线波束扫描进行了理论分析,实现超宽带时域天线的波束扫描的关键是对各脉冲源触发时间进行精确的时间延时控制。比照相控阵雷达概念,提出了时控阵雷达的概念。根据工程需要研制出8路高精度延时控制器,以大量的实验证明了时域天线波束扫描理论的正确性和工程上的可行性。将经典的窄带雷达Kalman滤波跟踪理论引入到超宽带冲激雷达动目标跟踪理论,并指出冲激雷达由于采用回波识别检测方法,在跟踪关联上更有优势。最后为了超宽带冲激雷达动目标跟踪实验研究需要,研制出性能优越的全数字伺服系统,实验测试表明该伺服系统完全满足雷达跟踪要求。更多还原

【Abstract】 Ultra wideband (UWB) technology is widely attracting scholars and researchers because of it huge potential. In communication and radar fields, UWB technology has rapidly improved in recent years and may be causing a new technical revolution. As a kind of UWB radar, UWB impulse radar transmits and receives short pulse signals, then achieves some useful information of target from echo, such as distance, velocity and construction, etc. Relative to traditional radar, UWB impulse radar has very wide work band, so it has much advantage and huge military application merit. Because of the easier technology, short-range UWB impulse radar has been rapidly developed, and some productions have been manufactured. But there are few reports about middle- and far-range UWB impulse radar, so the theory and pivotal technology are expected to be deeply developed.In the period of "the tenth five-year plan", a UWB impulse radar system is built, its maximum detection range 5 km, and much study on the theory and experiment about middle- and far-range UWB impulse radar has been accomplished in our laboratory. This paper is subsequent study, and emphasizes on the theory and pivotal technology of moving-target detection (MTD) and tracking.Firstly, the pulse source of middle- and far-range is deeply studied. The influential factors on the stability index of a pulse source are minutely analyzed, and full-solid and high-stability pulse source units, based on avalanche dynatron, are designed. Through tow coherent synthesis of units, circuital and special types, high-power and high-repetitive pulse sources are designed, which is necessary for the middle- and far-range detection of UWB impulse radar.Secondly, the methods of UWB impulse radar moving-target detection are the study emphasis of the paper. Time-domain Doppler velocity-measuring is an important kind of the methods, and the principle is deeply analyzed, then it is pointed that the effective integration of echoes is the pivotal problem of velocity-measuring. To accumulate echo signals and improve measurement accuracy, three methods are put forward: arrived time estimating, subsection accumulating and subsection accumulating of arrived time estimating. And, their accumulating effect and applicability is analyzed. it is shown through a lot of simulation that echo signals can be effectively accumulated by forward methods in their applicability range. And, a new method of velocity-measuring, time-domain cancellation of echo waveform, is put up. The method converts time difference of arrival as voltage which is measured to compute the velocity of target.The theory of time-domain antenna array scan is analyzed. To realize time-domain antenna array scan, the pivotal problem is accurate delay-controlling to trigger of pulse sources. Contrasting to phased-array radar, the concept of timed- array radar is pointed out. According to the engineering requirement, eight-way delay-controller is designed, and many experiments are finished to validate the theory.Kalman filtering and tracking is traditional theory. It is introduced in moving-target tracking of UWB impulse radar in this paper.Finally, to realize moving-target tracking of UWB impulse radar, a full-numeric servo system which has excellent performance is designed. The experiment proves that the servo system can satisfy the requirement of tracking.更多还原