共查询到19条相似文献,搜索用时 140 毫秒
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频率综合器是被动式小型铷原子频标的关键部件之一,本文介绍了一个新型频率综合器的组成与工作原理,测试表明,该频率综合器具有信号频谱纯度高,体积小及功耗低的特点。 相似文献
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频率合成与频标技术的应用日益广泛。频率综合器是组成铷频标的关键仪器之一,作者研制成一种用于小型铷频标的新型频率综合器,体积小,功耗低,输出信号频谱纯度较高,主,旁频比可达35db以上,文章描述了其总体设计方案和运行机理。 相似文献
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频率综合器是被动式小型铷原子频标的关键部件之一。本文介绍了一个析型频率综合器的组成与工作原理。测试表明,该频率综合器具有输出信号频谱纯度高,体积小及功耗的的特点。 相似文献
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本文概述了原子频标技术的发展。给出了各种实用原子频率标准的目前现状以及它们性能指标的最新结果。对有前景的新型原子频标的研究进展也进行了介绍与评述。 相似文献
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Research on the magnetron cavity used in the rubidium atomic frequency standards is developed, through which the main characteristic parameters of the magnetron cavity are studied,mainly including the resonant frequency,quality factor and oscillation mode.The resonant frequency and quality factor of the magnetron cavity were calculated,and the test results of the resonant frequency agreed well with the calculation theory.The test results also show that the resonant frequency of the magnetron cavity can be attenuated to 6.835 GHz,which is the resonant frequency of the rubidium atoms,and the Q-factor can be attenuated to 500-1000.The oscillation mode is a typical TE011 mode and is the correct mode needed for the rubidium atomic frequency standard.Therefore these derivative magnetron cavities meet the requirements of the rubidium atomic frequency standards well. 相似文献
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M. V. Kartikeyan E. Borie B. Piosczyk O. S. Lamba V. V. P. Singh A. Mobius 《International Journal of Electronics》2013,100(6):709-723
This paper deals with the conceptual design of a 42 GHz, 200 kW continuous wave gyrotron operating in the TE 5,2 mode with radial output coupling. The basic motivation and selection criteria are discussed and the design of the resonant cavity, magnetron injection gun, radio frequency (RF) guiding system, quasioptical output coupler and RF window is presented. 相似文献
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为了提高磁控管稳定性,需要研究各耦合因素对磁控管谐振频率及模式分隔度的影响。该文采用等效电路的方法,给出了无隔模带磁控管在电容、电感耦合下的谐振频率及模式分隔度的表达式,并分析谐振频率随模数的变化趋势及电感、电容耦合强弱对模式分隔度的影响。采用CST-MWS软件对不同阴极半径及顶盖高度的谐振系统的谐振频率进行仿真,并将仿真结果与理论结果进行对比。理论分析与计算机仿真表明,对于无隔模带磁控管谐振系统,电容耦合使谐振频率随模数的增大而增大,电感耦合使谐振频率随模数的增大而减小;两者分别通过增大和降低模频率从而增大模式分隔度,两者共同作用时模谱图取决于占主导地位的耦合因素。 相似文献
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采用有限元方法计算了二维方形介质腔和二维微盘的谐振频率和品质因子,并给出了两种腔中磁场、电场振幅分布图,介质腔中的谐振问题对应亥姆霍兹波动方程的本征值问题,本征值的实部和虚部与谐振腔Q值关联;比较了近似解析解、FDTD解、FEM解的结果,对于谐振频率比较,FEM和解析解更接近,对于品质因子比较,低Q值结果FDTD和FEM结果相近,高Q值结果两者相差较大。通过比较知道,FEM方法比时域有限差分方法计算更准确,求解速度更快。 相似文献
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The instability of passive atomic frequency standards caused by shot noise introduced by the atomic reference is calculated. This instability can be characterized by a figure of merit for the atomic reference, and the asymptotic functions for the rms frequency fluctuation for long and short averaging times expressed in terms of this quantity. Measurements of the rms frequency fluctuation of cesium atomic beam and rubidium vapor frequency standards are compared with theory, and the predicted performances of various existing and proposed atomic standards are tabulated. It is feasible to build atomic beam frequency standards whose stability for averaging times less than one second is limited by noise in the crystal oscillator rather than by shot noise, a criterion generally met by rubidium vapor frequency standards. For long averaging times, shot noise will always be the fundamental limiting factor in atomic frequency standard stability. 相似文献
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A new type of complex cavity structure is used to improve the selectivity of modes in gyrotron resonant cavity with a rational position of inter-cavity wall and the shape of coupling holes between inter- and outer-cavities. The resonant characteristics of the complex cavity operating in TE021/TE031 mode at Ka frequency band are simulated and analyzed with Ansoft HFSS code, which shows that mode competition can effectively be alleviated with the cavity structure and it may be useful to the formation of clustered-cavity for extending interaction frequency bandwidth. 相似文献
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研究了LD抽运的、频差可调的双频Nd:YVO4微片激光器的光谱特性。对于荧光谱宽固定的激光增益介质,输出激光的光谱特性主要与抽运功率、抽运位置和谐振腔长等参数相关;通过控制相关参数,可以调整输出激光不同波长频谱峰之间的相对频差。实验结果表明,当LD抽运电流为14.5A时,抽运光与谐振腔模达到良好的匹配,输出稳定的双纵模双频激光,相应的频差可超过90GHz;改变抽运参数相应频差在92.22~94.24GHz之间变化;增加谐振腔的腔长时,输出的激光纵模间隔减少并可输出三纵模,其中两频峰之间的最小频差可达到26.50GHz。 相似文献