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毫米波自差频CW系统发射漏波信号对接收灵敏度的影响 被引量:2
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作者 陈墨 徐金平 《东南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2009年第2期206-210,共5页
针对Ka波段自差频式连续波(CW)多普勒雷达系统中发射漏波信号对接收灵敏度的影响问题,通过计算机建模仿真和实验测试,对存在发射功率泄漏干扰情况下一个接收系统前端(包括低噪声放大器和混频器)的工作性能进行了深入研究.结果表明,在收... 针对Ka波段自差频式连续波(CW)多普勒雷达系统中发射漏波信号对接收灵敏度的影响问题,通过计算机建模仿真和实验测试,对存在发射功率泄漏干扰情况下一个接收系统前端(包括低噪声放大器和混频器)的工作性能进行了深入研究.结果表明,在收发隔离度为26dB时,系统所允许的最大发射漏波信号功率电平为-11dBm,接收系统前端增益恶化小于2.5dB.根据这些参数,通过合理设计发射功率电平和收发隔离度,可以保证接收系统的探测灵敏度指标的实现. 展开更多
关键词 CW多普勒雷达 自差频 收发隔离 接收灵敏度
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飞秒激光脉内自差频产生中红外激光研究进展 被引量:3
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作者 王庆 漆磊 +1 位作者 王润雨 李岩 《激光与光电子学进展》 CSCD 北大核心 2021年第17期1-15,共15页
基于飞秒激光脉内自差频技术产生中红外波段激光的技术已取得较大的进步,并被广泛地应用在物理学、化学以及生物医学等重要科学领域。对中红外超短激光脉冲的发展与研究背景进行了介绍;阐述了飞秒激光脉内自差频产生中红外激光的基本原... 基于飞秒激光脉内自差频技术产生中红外波段激光的技术已取得较大的进步,并被广泛地应用在物理学、化学以及生物医学等重要科学领域。对中红外超短激光脉冲的发展与研究背景进行了介绍;阐述了飞秒激光脉内自差频产生中红外激光的基本原理;综述了基于钛宝石激光器、1μm波段飞秒固体激光器、2μm波段飞秒固体激光器及光纤激光器作为驱动源并通过脉内自差频技术产生中红外飞秒激光的研究进展,并对不同波段驱动源进行了对比分析;最后对脉内自差频产生中红外飞秒激光的未来发展方向进行了展望。 展开更多
关键词 激光光学 飞秒激光 脉内自差频 中红外激光 宽光谱
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基于光纤延时声光频移自差拍法快速测量激光线宽 被引量:5
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作者 白建东 王杰英 王军民 《激光与光电子学进展》 CSCD 北大核心 2016年第6期225-230,共6页
基于光纤延时声光调制器(AOM)频移自差拍法实验研究了不同线宽激光的功率谱特性,并作了相关的仿真分析;同时,提出了利用短光纤测量窄线宽激光器线宽的一种简单方法。当光纤延时时间小于激光器的相干时间时,自差拍频谱的3dB带宽不能直接... 基于光纤延时声光调制器(AOM)频移自差拍法实验研究了不同线宽激光的功率谱特性,并作了相关的仿真分析;同时,提出了利用短光纤测量窄线宽激光器线宽的一种简单方法。当光纤延时时间小于激光器的相干时间时,自差拍频谱的3dB带宽不能直接用于标定激光线宽。理论分析和实验均表明,此时激光的线宽信息主要由自差拍频谱中两翼的周期性振荡成分决定,几乎不受中央尖峰的影响。根据最小二乘法理论,对实验所测的自差拍频谱进行理论拟合可获得待测激光的线宽。该方案基本不受延时自差拍系统最小分辨率的限制,可以用于激光线宽的快速测量,特别是窄线宽激光的测量。 展开更多
关键词 激光光学 窄线宽光纤激光器 光纤延时声光自差拍法 线宽测量 短光纤
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Analysis and Optimum Design of Differential Inductors Using Distributed Capacitance Model
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作者 菅洪彦 唐长文 +1 位作者 何捷 闵昊 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2005年第6期1077-1082,共6页
A distributed capacitance model for monolithic inductors is developed to predict the equivalently parasitical capacitances of the inductor.The ratio of the self-resonant frequency (f SR) of the differential-driven sym... A distributed capacitance model for monolithic inductors is developed to predict the equivalently parasitical capacitances of the inductor.The ratio of the self-resonant frequency (f SR) of the differential-driven symmetric inductor to the f SR of the single-ended driven inductor is firstly predicted and explained.Compared with a single-ended configuration,experimental data demonstrate that the differential inductor offers a 127% greater maximum quality factor and a broader range of operating frequencies.Two differential inductors with low parasitical capacitance are developed and validated. 展开更多
关键词 distributed capacitance model self-resonant frequency ratio quality factor differential inductor optimum design
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Regulations, Nations, and Freedom of Speech: A Cultural and Legal Analysis of Video Game Regulation
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作者 Laura Stoltzfus 《Sino-US English Teaching》 2014年第3期206-218,共13页
As the video game industry has firmly established itself as an art form as well as entertainment, certain games and content have led to legal issues in several countries. These court cases usually fall under freedom o... As the video game industry has firmly established itself as an art form as well as entertainment, certain games and content have led to legal issues in several countries. These court cases usually fall under freedom of speech and expression. The author has studied three of the five top video game producing and purchasing markets in the world--the United States, Japan, and the Republic of Korea--to explore how each country regulates this industry These three countries explicitly guarantee their citizens the freedoms of speech and expression, but, due to cultural differences and historical interpretations of those rights, the policies concerned with gaming have been handled differently by each country. The argument of the author is that historic interpretations of freedom of speech in legal cases can inform how video games and content controversy will be decided by the constitutional courts in these three countries. Japan and the Republic of Korea, for example, have historically interpreted freedom of speech rights in a way that benefits the citizenry as a whole, marking them as more collective. The United States has historically interpreted freedom of speech and expression in a way that benefits individual citizens, marking it as individualistic. These cultural aspects of how legal decisions are reached has affected the relatively new technology of video games 展开更多
关键词 freedom of speech video game regulation Japan Republic of Korea individualist/collectivist
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