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间歇式高速同步相机新型全数字化微机控制系统 总被引:2,自引:2,他引:0
本文提出了一种间歇式高速同步相机的全新设计方法,介绍了系统的工作原理,硬件,软件设计以及核心控制算法,最后给出了实际应用结果。 相似文献
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现代频率合成技术综述 总被引:18,自引:0,他引:18
本文阐述了国内外现代频率合成技术在现代电子系统应用中的重要性,综述了现代频率合成技术朝着系列化、小型化、模块化和工程化方向的发展趋势,着重叙述了应用最为广泛的锁相式(PLL)频率合成器和直接数字式频率合成器(DDS)的国内外最新进展,本文还详细介绍了单片PLL频率合成器、算术锁定环、单片DDS芯片等先进器件,以及锁频环路、上变频、小型化等先进技术。 相似文献
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高速A/D转换器动态参数的计算机辅助测试 总被引:1,自引:0,他引:1
模拟/数字转换器是电子器件中比较特殊和关键的器件。随着器件时钟频率的不断提高,如何高效、准确地测试AID转换器的动态参数是当今高速A/D转换器测试研完的重点。文章以逻辑分析仪和Matlab软件为基础,运用相干采样技术,针对10位40MSPSA/D转换器动态参数的测试和基波图形恢复算法进行了深入研究。给出了研究结果,指出了测试中有待完善的地方。 相似文献
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本文介绍了基带数字相干解调的载波恢复锁相环的结构原理,并对其进行了性能分析。与四倍频方法比较,在相同条件下,前者比后者环路信噪比高5--10dB。实验结果表明,恢复的载波稳定性良好。 相似文献
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In previous article [M. Zhan, Phase-lock equations and its connections to Ginzburg–Landau equations of superconductivity, J. Nonlinear Anal. 42 (2000) 1063–1075], we introduced a system of equations (phase-lock equations) to model the superconductivity phenomena. We investigated its connection to Ginzburg–Landau equations and proved the existence and uniqueness of both weak and strong solutions. In this article, we study the steady-state problem associated with the phase-lock equations. We prove that the steady-state problem has multiple solutions and show that the solution set enjoys some structural properties as proved by Foias and Teman for the Navier–Stokes equations in [C. Foias, R. Teman, Structure of the set of stationary solutions of the Navier–Stokes equations, Commun. Pure Appl. Math. XXX (1977) 149–164]. 相似文献
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在无线电通信中,多用户通信可以采用时分多址(TDMA)、频分多址(FDMA)或者码分多址(CDMA)技术来实现,在水声通信中,信道的多途传播特性带来的空间差异,提供了另外的多用户通信手段。时间反转(或相位共轭)技术,能够实现对空间中指定点的聚焦接收和多途压缩,它为空间位置不同的多个用户提供了相互独立的通信通道,能够很好地克服用户之间的同道干扰(CI)。本文在垂直阵接收的基础上,利用时间反转技术来实现不同用户在同一信道中的同时通信,结合带锁相环的自适应判决反馈均衡技术来消除残余的多途码间干扰,并进行了初步的海上试验,实现了两个不同深度上用户的同时通信。 相似文献
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Miin-Shyue Shiau Heng-Shou Hsu Ching-Hwa Cheng Hsiu-Hua Weng Hong-Chong Wu Don-Gey Liu 《Microelectronics Journal》2013
In this paper, the charge pump (CP) based on a switches-in-source architecture is to be improved by gain-boosting amplifiers for phase-locked loops (PLLs). In our design, two differential amplifiers were employed in this CP to reduce the effect of the channel length modulation in MOS transistors. As a result, the up and down currents will be rather independent of the output voltage transformed by the capacitive low pass filter (LPF). This circuit was implemented using TSMC 0.18-μm CMOS technology and was investigated at a power supply of 1.8 V. The measured mismatch was less than 1% for the output voltage ranging from 0.4 to 1.4 V. This result is lower than that of the dynamic current-matching CP with feedback tuning on the same architecture. A comparison will be presented and discussed. 相似文献
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Mei-Qin Zhan 《Journal of Mathematical Analysis and Applications》2008,340(1):126-134
In this article we shall show that the Ginzburg-Landau equations admit at least three time-periodic solutions. One of the time-periodic solutions describes the non-superconductive (or normal) state and the other one describes the superconductivity state. We will also show that the time-periodic solutions are exponentially stable. Furthermore, the method we use in this article can be used to find numerical approximations to the time-periodic solutions. 相似文献
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