共查询到18条相似文献,搜索用时 703 毫秒
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结构参数对小型氢频标磁控管微波腔谐振频率的影响 总被引:2,自引:0,他引:2
本文概述了小型氢频标磁控管微波腔的结构参数及其性能要求,指出在1到10GHz之间,一般随着电极缝隙数和缝隙间距的增加,随着筒直径、壳电极直径和壳电极厚度的减小,微波腔谐振频率随之增加;反之则减小. 相似文献
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设计并实现了一种用于铷原子频标的小型化锁频环路。采用数字锁相倍频技术,实现了10MHz信号的45.5645833次倍频。再经过一级15次倍频后获得频率为6834.6875MHz的铷原子频标微波探寻信号。通过数字电路技术实现了455.645833MHz信号的小调频。测量并分析了455.645833MHz信号的相位噪声,结果表明电路系统对铷频标频率稳定度的贡献为3.2×10-12τ-1/2。测量了利用该电路得到的铷频标的短期频率稳定度,结果为5×10-12τ-1/2(1s≤τ≤100s),明显高于一般商品小型化铷原子频标。 相似文献
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实验以上海天文台SOHM-4型氢原子钟脉泽信号和新研制的模拟-数字混合型锁相环路为基础,主要分析锁相环路参数对氢原子钟输出信号的短期频率稳定度和单边带相位噪声的影响。针对氢脉泽信号高Q值的特殊性,通过理论分析和实验验证寻求与其相匹配的最佳环路参数。实验结果表明,锁相环路的参数设置直接影响到氢原子钟输出信号的性能;在脉泽信号不变的情况下,改进后的锁相环路和主电子学系统可使氢原子钟的频率稳定度提高至1.7×10-13/1s, 3.3×10-14/10s, 9.1×10-15/100s, 2.9×10-15/1 000s, 1.4×10-15/10000s,即较之原有的技术指标,在各取样时间范围内,频率稳定度的测试结果均提高了半个量级。 相似文献
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Prestage J.D. Tjoelker R.L. Wang R.T. Dick G.J. Maleki L. 《IEEE transactions on instrumentation and measurement》1993,42(2):200-205
The frequency stability of an atomic standard based on 199 Hg+ ions confined in a hybrid RF/DC linear trap is described. The 40.5-GHz clock transition has been measured to be 17 mHz wide, representing a quality factor greater than 2×1012. A 160-mHz line is used to steer the output of a 5-MHz crystal oscillator to obtain a stability of 2×10-15 for 24000-s averaging times. In a separate measurement, a 37-mHz line is used to steer the output of the superconducting cavity maser oscillator to reach 1×10-15 stability at 10000 s 相似文献
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原子时标TA(NIM)是一个独立时标,其频率由NIM5铯喷泉基准驾驭。产生时标的主钟是一台主动型氢原子钟,铯喷泉基准定期对其测量和校准。时标算法通过预估氢钟将来的频率,补偿过去预估频率与校准频率之差,并评估无校准数据期间的氢钟频率,最终尽可能实现TA(NIM)的频率与NIM5铯喷泉基准保持一致。2007年8月,TA(NIM)开始试运行,2008年6月正式运行。1年多来的数据分析表明,TA(NIM)运行连续可靠,与TAI间的时间稳定度(5天)达到1.2 ns,相对频差为2.0×10-15。 相似文献
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Jinquan Deng Jinting Liu Shaofeng An Yongfang Tan Xiwen Zhu 《IEEE transactions on instrumentation and measurement》1994,43(4):549-552
Light shifts in a diode-laser-pumped 87Rb maser under the various conditions of laser intensities and frequency detunings were measured, and a linear dependence of the maser frequency on the laser intensities and frequencies was derived. The pulling coefficient of the maser frequency from the laser was found to be about 2.9×10-3 , and the light shift could be minimized when the laser frequency was adjusted to near the center frequency of the resonance cell 相似文献
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介绍了基于光腔衰荡光谱法测定气体中的微量水的方法原理,该方法适用于含量为0.2×10-9~20×10-6 mol/mol的所有气体中水分的测定。建立了光谱分析法的原始数学模型,对测定方法的不确定度进行了评估,结果表明该方法的扩展不确定度为(8~20)×10-9 mol/mol(k=2,p=95%)。 相似文献
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Jinquan D. Xiwen Z. Yuanhai X. 《IEEE transactions on instrumentation and measurement》1993,42(3):755-758
Experiments on the 87Rb maser with both ends pumping showed variations of the maximum output power versus cell temperature. The largest output power was 2.0×10-10 W, and a preliminary measurement gave an improved short-term frequency stability. The results of the numerical calculations based on the density matrix formalism agreed qualitatively with the experiments 相似文献
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A 100000-A, high precision device of the magnetic modulation current comparator type, which can be used in industrial heavy direct current systems for online calibration and measurement, is presented. Testing of the comparator indicates that its current ratio accuracy is 5×10-5, and that measurements of voltage with a standard resistor achieve an accuracy of 5×10-4. These are slightly degraded to 3×10-4 for on-site calibration and 1×10-3 for on-site measurement. The device, which has a toroidal configuration, can be opened for each installation on a busbar, with a variation in accuracy of less than 2×10-5. Its magnetic shielding renders it insensitive to magnetic fields up to 1×10-2 Tea. Its accuracy is better by a factor of two than that of similar industrial measuring devices. The principle of operation and the characteristics of the comparator, the double shielded design, and an analysis of its errors are discussed 相似文献