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基于FPGA的瞬时频率指示器保宽脉冲提取方法 被引量:1
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作者 刘俊杰 张志聪 +1 位作者 凌晓华 何仁伦 《遥测遥控》 2019年第2期46-50,共5页
电子战ESM系统中,保宽脉冲的提取具有十分重要的意义。瞬时频率指示器作为重要的电子战设备,其传统的保宽脉冲提取方法存在诸多缺点。提出一种基于FPGA的双门限、交直流耦合的处理方法,具有信号适应性强、保宽脉冲提取准确度高等特点。... 电子战ESM系统中,保宽脉冲的提取具有十分重要的意义。瞬时频率指示器作为重要的电子战设备,其传统的保宽脉冲提取方法存在诸多缺点。提出一种基于FPGA的双门限、交直流耦合的处理方法,具有信号适应性强、保宽脉冲提取准确度高等特点。试验结果表明,设计方案可行,达到预期的各种指标要求。 展开更多
关键词 电子战 保宽脉冲 瞬时频率指示 双门限
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声音共鸣演示实验的改进 被引量:1
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作者 杨向阳 《中小学实验与装备》 1994年第4期12-12,共1页
声音共鸣演示实验的改进恩施一中杨向阳(445000)一、特点取材方便,效果明显,操作简单。二、器材J2462低频信号发生器,乳胶管一米左右,废日光灯管两支,喇叭一个,支架一个。三、制做方法首先用玻璃刀将两支灯管的两头... 声音共鸣演示实验的改进恩施一中杨向阳(445000)一、特点取材方便,效果明显,操作简单。二、器材J2462低频信号发生器,乳胶管一米左右,废日光灯管两支,喇叭一个,支架一个。三、制做方法首先用玻璃刀将两支灯管的两头截去,用水把灯管内壁冲洗干净,然后... 展开更多
关键词 演示实验 低频信号发生器 空气柱 玻璃管 固有频率 上下移动 频率指示 制做方法 乳胶管 调节频率
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一种超宽带电子战测频技术的研究 被引量:4
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作者 文富忠 胥全春 +1 位作者 韩学涛 程号 《遥测遥控》 2021年第1期56-63,共8页
随着雷达技术的发展,宽带瞬时信号截获是信息化装备的必备功能单元。从理论和试验验证的角度详细分析了超宽带电子战接收机的工作原理、测频技术和应用场景,提出了一种简化的MonoDFT算法,实现了2GHz~18GHz频段内雷达信号辐射源的高精度... 随着雷达技术的发展,宽带瞬时信号截获是信息化装备的必备功能单元。从理论和试验验证的角度详细分析了超宽带电子战接收机的工作原理、测频技术和应用场景,提出了一种简化的MonoDFT算法,实现了2GHz~18GHz频段内雷达信号辐射源的高精度频率测量,并设计了两种应用场景和实现方法。理论分析与实验表明,接收机能够实现瞬时带宽16GHz,灵敏度优于-70dBm,测频精度优于0.4MHz,延迟时间小于270ns,可广泛应用于电子战领域,具有很高的工程应用价值。 展开更多
关键词 瞬时测频接收机 瞬时频率指示 单比特数字接收机 电子战 测频
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DOA ESTIMATION FOR WIDEBAND SOURCES BASED ON UCA 被引量:3
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作者 Yang Liming Zhang Hou Yang Xiaorong 《Journal of Electronics(China)》 2006年第1期128-131,共4页
A new Direction Of Arrival (DOA) estimation algorithm for wideband sources based on Uniform Circular Array (UCA) is presented via analyzing widcband performance of the general ESPRIT. The algorithm effectively imp... A new Direction Of Arrival (DOA) estimation algorithm for wideband sources based on Uniform Circular Array (UCA) is presented via analyzing widcband performance of the general ESPRIT. The algorithm effectively improves the wideband performance of ESPRIT based on the interpolation principium and UCA-ESPRIT. The simulated results by computer demonstrate its efficiency. 展开更多
关键词 WIDEBAND Uniform Circular Array (UCA) Direction Of Arrival (DOA)
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MICRO-MOTION TARGET SENSING BY STEPPED-FREQUENCY CONTINUOUS-WAVE RADAR
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作者 Kong Lingjiang Zhou Yongshun Cui Guolong Yang Jianyu 《Journal of Electronics(China)》 2009年第6期782-787,共6页
Mechanical micro-vibration of a target may induce phase modulations on the radar echo,and the vibration can be detected to identify micro-motion target. In this paper,a new method to detect a micro-motion target and o... Mechanical micro-vibration of a target may induce phase modulations on the radar echo,and the vibration can be detected to identify micro-motion target. In this paper,a new method to detect a micro-motion target and obtain its range and micro-motion frequency is proposed in which multiple periods stepped-frequency continuous-wave signal and Moving Target Indication (MTI) filter are adopted. The simulation results illustrate the validity of this method and present the detection of the target range and the vibration frequency. The experiment gives promising results. 展开更多
关键词 MICRO-MOTION MICRO-DOPPLER Stepped-frequency continuous-wave MTI (Moving TargetIndication)
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Hitchhiker's guide to genetic diversity in socially structured populations
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作者 L. S. PREMO 《Current Zoology》 SCIE CAS CSCD 2012年第2期287-297,共11页
When selection increases the frequency of a beneficial gene substitution it can also increase the frequencies of linked neutral alleles through a process called genetic hitchhiking. A model built to investigate reduce... When selection increases the frequency of a beneficial gene substitution it can also increase the frequencies of linked neutral alleles through a process called genetic hitchhiking. A model built to investigate reduced genetic diversity in Pleistocene hominins shows that genetic hitchhiking can have a strong effect on neutral diversity in the presence of culturally mediated mi- gration. Under conditions in which genetic and cultural variants are transmitted symmetrically, neutral genes may also hitchhike to higher frequencies on the coattails of adaptive cultural traits through a process called cultural hitchhiking. Cultural hitchhiking has been proposed to explain why some species of matrilineal whales display relatively low levels of mitochondrial DNA diver- sity, and it may be applicable to humans as well. This paper provides a critical review of recent models of both types of hitch- hiking in socially structured populations. The models' assumptions and predictions are compared and discussed in the hope that studies of reduced genetic diversity in humans might improve our understanding of reduced genetic diversity in other species, and vice versa 展开更多
关键词 Cultural group selection Cultural hitchhiking Culturally mediated migration Diversity Evolution Genetic hitch- hiking
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