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基于雷达宽带回波的目标测距和测速方法 总被引:2,自引:0,他引:2
目标特性测量雷达一般采用宽窄带交替的工作方式,宽带用于获得目标高分辨特征信息,窄带用于目标检测和跟踪.如果雷达只采用宽带工作方式就能够既进行目标检测和跟踪,又能获得目标高分辨特征,则可以降低雷达系统的复杂性,并节约雷达的时间能量.文中提出了一种基于雷达宽带回波的目标测昔方法,该方法利用多个宽带回波的幅度和相位信息测苗目标距离和速度,实际数据的实验结果验证了该方法具有较高的测距和测速精度. 相似文献
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宽带雷达系统测试和性能评估中目标信息模拟精度和分辨率要求很高。针对宽带线性调频雷达运动目标的回波脉冲内多普勒频率呈现线性调频(LFM)变化特征、回波脉冲之间具有时移分布和相位相干特性的问题,采用基于数字射频存储(DRFM)系统的回波脉冲内LFM多普勒频率调制、多回波相参脉冲信号之间时移模拟的方法。探讨了基于宽带DRFM系统的高精度和高分辨率的运动目标多普勒频率信息实时模拟方法。采用仿真分析和实验验证方法,证实算法性能,运动目标的多普勒频率模拟精度/分辨率在特定条件下可达到Hz级。 相似文献
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提出了一种改进型的动目标检测(MTD)跟踪目标设计,该方法可根据目标速度实时计算信号周期,保持目标回波始终位于非关断滤波器内,通过参数设计控制目标回波的频谱远离关断滤波器,保证目标回波信号始终被检测到,MTD 处理方法又可实时测量目标的速度,形成闭环的自适应周期MTD 跟踪。该方法在某型雷达上得到应用,性能良好。 相似文献
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Hatakeyama K. Togawa H. Kawamura T. Sato Y. 《Electromagnetic Compatibility, IEEE Transactions on》1992,34(4):397-403
For measurements of reflection coefficients in an anechoic chamber by the free-space voltage standing wave ratio (VSWR) method, the composite antenna technique, using a combination of two antennas, is proposed. Reliable data on reflection coefficients can be obtained by this technique, with respect to reflected waves from arbitrary directions. Using the measurement results, the direction dependency of reflection coefficients is studied in relation to specular reflection and to the directivity of a transmitting antenna 相似文献
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随着5G移动通信频段的公布,传统基站天线已不足以覆盖其工作频段。文章以紧耦合阵列天线理论为基础,提出了一种基于紧耦合结构的交叉偶极子宽带基站天线。该天线由两对正交的领结状偶极子天线构成,通过两对交叉偶极子之间的耦合效应,有效地展宽了天线的阻抗带宽。同时,通过在天线和金属反射板之间加载电阻型频率选择表面,吸收由反射板引入的谐振反射波,改善天线高频端辐射性能。仿真及测试结果表明:该天线在1.7-3.6 GHz 频率范围内,可以满足基站天线的设计指标,两端口驻波比均小于1.5,两端口之间隔离度大于55 dB,半功率波束宽度满足65°±5°范围,且整个频段内增益均大于8.5 dBi。 相似文献
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主要研究射频识别(Radio Frequency Identification,RFID)多频点联合测距系统中如何检测标签反射信号以及如何提高信道估计精度的问题.首先,提出了一种标签反射信号的检测方法,利用标签反射信号的功率谱特性,通过分析接收信号的能量谱,识别标签反射信号得到识别信号,再利用能量检测方法对识别信号进行范围限制得到检测信号;然后,改进RFID的传统信道估计方法,以提高信道估计精度;最后,搭建了多频点联合测距系统以验证系统性能.实验结果表明,该系统具有较高的检测效率;经改进的信道估计方法能有效减小载波相位的方差;系统平均测距误差约为2.5 cm,实现了厘米级测距. 相似文献
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为克服无线通信中系统间的相互干扰,采用频带抑制技术设计了一种具有双阻带特性的超宽带单极子天线。首先采用共面波导进行馈电,辐射贴片和共面波导均为阶梯结构,使其在2.9~12GHz频带内电压驻波比小于2;其次在辐射贴片上分别引入C形和倒U形槽谐振结构,使其在3.3~3.9GHz和5.1~5.9GHz的频带内电压驻波比大于2;最后通过仿真与测量,验证该天线实现了良好的频带抑制功能。 相似文献
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针对现有无线射频信号的手势识别研究中的数据预处理和特征利用问题,该文提出一种用于调频连续波(FMCW)雷达的时空压缩特征表示学习的手势识别算法。首先对手部反射的毫米波雷达回波信号的距离-多普勒(RD)图进行静态干扰去除和动目标点筛选,减少杂波对手势信号的干扰,同时减少计算数据量;然后提出一种压缩手势时空特征的表示方法,利用动目标点的主导速度来表示手势的运动特征,实现多维特征的压缩映射,并保留手势运动的关键特征信息;最后设计了一个单通道的卷积神经网络(CNN)来学习和分类多维手势特征信息并应用于多用户和多位置的手势识别。实验结果表明,与现有其他手势识别算法相比,该文提出的手势识别方法在识别精度、实时性以及泛化能力上都具有明显的优势。 相似文献
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In millimeter wave cellular networks,the spectrum efficiency of multi-operator dual frequency hybrid spectrum access scheme under open access mode was studied.Firstly,Poisson point process was used to model the distribution of base stations of each operator,the base station and carrier frequency were selected by users based on maximum received power criterion and high frequency carrier signal to interference plus noise ratio (SINR) threshold access criterion respectively.Secondly,the rate coverage was used as performance criteria to study the spectrum efficiency,and the theoretical expression of rate coverage was derived based on stochastic geometry theory according to channel model,path loss model and antenna model.Finally,the influence of user density,base station density and antenna gain on rate coverage was analyzed by simulation.The experimental results show that the multi-operator dual frequency hybrid spectrum access scheme has better spectrum utilization efficiency. 相似文献
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《Microwave Theory and Techniques》1971,19(3):337-338
A simple tuning circuit for source or load matching is described that makes possible smooth and sensitive adjustments with no "holes" in frequency coverage over a complete waveguide band. Energy is coupled out of the mainline, the phase and magnitude adjusted with phase shifter and attenuator and fed back into the mainline to cancel the reflected signal. A simple analysis of the circuit is presented, and a graph given for estimating the maximum voltage standing-wave (VSWR) that can be "tuned out." Application to measurement of reflection coefficient or to impedance is proposed. 相似文献
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Yu. B. Bashkuev M. G. Dembelov A. A. Pylaev L. G. Tamkun 《Journal of Communications Technology and Electronics》2012,57(3):271-277
Diurnal and seasonal variations of the signal reflected from the ionosphere are investigated on the basis of regular measurements
of the amplitude and phase of the radio field of a reference radio station operating at a frequency of 50 kHz. The reflected
signal is extracted from the mixture of the ground-wavel and reflected-wave fields using a special procedure. Effective parameters
of an exponential ionospheric model, which characterize the statistical parameters of the signals in the long-wave band at
medium distances, are proposed. 相似文献
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《Microwave Theory and Techniques》1967,15(9):504-507
An analysis is given of the "quarter-wave" impedance measurement technique. This technique, which finds its widest potential application in conjunction with standing wave machines, permits the approximate elimination of the error due to residual reflection or VSWR. If the other sources of error are small, the potential reduction in error is in the ratio |t/sub 11|/2|S/sub 11/|, where S/sub 11/ and t/sub 11/ are the residual reflection coefficients of the standing wave machine and quarter-wavelength section, respectively. 相似文献