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毫米波连续波雷达载波泄漏对消——理论分析与系统仿真 总被引:6,自引:1,他引:5
对限制连续波体制雷达系统作用距离的载波泄漏问题仔细地作了探讨,对各种连续波体制载波泄漏有源对消方法进行了理论分析,并针对毫米波宽带调频雷达实际泄漏信号的特点进行了对消环路的系统仿真。结果表明设计良好的对消系统能有效地抵消载波泄漏功率达30 ̄60dB,对进一步作实验研究提供了理论基础。 相似文献
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调频连续波雷达泄漏信号抑制技术综述 总被引:1,自引:0,他引:1
泄漏信号的抑制技术是提高调频连续波(Frequency Modulated Continuous Wave,FMCW)雷达系统整体性能的关键点,一直受到业界以及学术界的广泛关注。综述了FMCW雷达泄漏信号抑制技术在国内外的发展历程及现状;分析了解决FMCW雷达中信号泄漏问题的关键技术,可归纳为基于收发天线控制的隔离技术、基于收发通道的对消技术以及基于现代信号处理的泄漏抑制技术,并详细讨论了各技术的原理、实际应用、优缺点;最后给出了FMCW雷达泄漏信号抑制技术研究的建议。 相似文献
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伪码调相连续波雷达泄漏对消方法研究 总被引:1,自引:0,他引:1
本文介绍了泄漏信号中频对消的一般方法,并针对连续波伪码调相信号提出了一种易于实现的中频对消方法,进行了理论分析和实验验证。实验证明本方法是可行的。 相似文献
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噪声准连续波雷达虽能有效解决发射泄漏问题,但其经调幅断续后的发射波形不再具有时域连续性的特点,不能充分发挥噪声连续波雷达的优势。为此提出在噪声连续波雷达中采用双频发射方式来对消泄漏信号。该雷达的发射信号采用双频发射方式,利用两个载频所调制的泄漏信号的脉压-快速傅里叶变换(FFT)频谱输出数据取模相等这一特点,将两个载频分离通道中取模后的脉压-FFT频谱数据相减,可有效消除泄漏信号及其产生的"噪声基底"。仿真结果表明:双频发射噪声连续波雷达在保留原有连续波雷达信号特点的基础上,其泄漏抑制能力要优于噪声准连续波雷达。 相似文献
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毫米波连续波雷达载波泄漏对消 总被引:1,自引:0,他引:1
简述了连续波雷达载波泄漏的成因,我们把调频连续波雷达载波泄漏的矢量对消方案同传统的载波泄漏矢量对消方案相比后提出了利用数字信号处理方法实现毫米波调频连续波雷达载波泄漏的宽带多点对消方案及其实现框图,引入了获得载波泄漏信号参数的模板匹配方法,并且通过实际数据的仿真计算,获得了良好的对消效果. 相似文献
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伪码连续波雷达抑制发射功率泄漏的新技术 总被引:1,自引:0,他引:1
伪码连续波雷达是一种新体制雷达,它采用PN码(m序列)连续波信号形式和脉冲压缩(PC)、脉冲多卜勒(PD)的信号处理技术,大大提高了在现代电子环境中的自卫能力、探测能力.文章研讨了一种抑制发射功率泄漏的新技术,理论分析和计算仿真证明,这种处理方法有极好的抑制发射机泄漏和杂波干扰的能力,并有效地解决了在大多卜勒频移条件下PN码脉压的方法.对量化精度的影响也进行仿真分析. 相似文献
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Experimental studies are presented of the random fluctuations of the laser light and of the diode current of continuous-wave multifilament GaAs laser diodes. Using the single-detector method, the intensity noise of the laser light of single, optically isolated filaments is measured in the central measuring frequency range 40 kHz-6 MHz. In the same frequency range, the intensity noise of the total laser light from one emitting face is also measured. The intensity noise of the laser light is found to depend strongly on the generation of lasing filaments in the p-n junction. The noise of the electrical excitation current depends also on the filamentary action. The laser-light noise and the current noise are correlated. The cross-correlation coefficient is measured between 40 kHz and 6 MHz as a function of the excitation current. The discovered correlation allows the application of a noise-modulation method to the laser light, which leads to a reduction of the laser-light noise-to-signal ratio. 相似文献
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《Electron Devices, IEEE Transactions on》1954,1(4):91-98
For some time the subject of noise generation in magnetrons has been under study in our laboratory. The unmodulated CW magnetron was chosen as the first subject for investigation, because some of the complications of pulsed or modulated tubes are thus avoided. Since any heterodyning method introduces the noise of another microwave oscillator, a method of direct detection has been employed. This method involves the use of a crystal-video receiver for both AM and FM detection. 相似文献
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Jeong-Geun Kim Sangsoo Ko Sanghoon Jeon Jae-Woo Park Songcheol Hong 《Microwave and Wireless Components Letters, IEEE》2004,14(9):443-445
Balanced topology in radar front-end is presented, which can reduce Tx leakage to receiver drastically. The balanced radar front-end which is composed of a differential cross-coupled oscillator, two Lange couplers, and a Wilkinson combiner is implemented using commercially available InGaP/GaAs heterojunction bipolar transistor technology. The tuning range of voltage control oscillator is 320 MHz from 25.307 to 25.627 GHz. The peak output power is 0.8 dBm. Average Tx-to-Rx isolation is about 40.5 dB. Since the isolation of the Lange coupler is 19 dB, the additional cancellation due to balanced topology is expected to be 21.5 dB. The chip size is 1.05 /spl times/ 1.70 mm/sup 2/. 相似文献
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Microwave solid-state devices such as impatts can provide moderately high levels of noise power. A simple noise radar has been demonstrated using a cable delay line and correlator. Further experiments for greater range using variable s.a.w. delay lines and downconversion of the microwave signal are outlined. 相似文献
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连续波(CW)雷达没有近距离盲区,但存在近距离信号泄漏和目标强回波干扰问题,严重影响雷达的探测性能。针对该问题,提出了一种基于单频调频信号的贝塞尔函数曲线特性进行近距离信号抑制的方法。首先建立了调频发射信号回波及I、Q解调数学模型,推导了调频信号的贝塞尔函数曲线特性;其次阐述了如何选择合适的调频频率和调频指数,能够更好的解决近距离干扰问题;最后,针对设置的参数进行仿真,结果表明该方法有效。 相似文献
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本文从理论上研究了附加相位调制抑制相位干涉噪声的方法 ,研究表明 :在光纤AM CATV外调制传输系统中 ,对传输光载波信号引入附加相位调制 ,当相位调制信号的频率为CATV频带的两倍以上时 ,可以有效地抑制相位干涉噪声的发生 ,抑制程度与相位调制度有关。 相似文献