时间频率公报 Pub Date : 2015-04-12 DOI: 10.1109/FCS.2015.7138939

G. Hummel, M. Rinaldi

引用次数: 4

Verification of time telegrams in Long Wave Radio systems 长波无线电系统时间电报的验证

时间频率公报 Pub Date : 2015-04-12 DOI: 10.1109/FCS.2015.7138839

Schneider Matthias, Ruland Christoph

{"title":"Verification of time telegrams in Long Wave Radio systems","authors":"Schneider Matthias, Ruland Christoph","doi":"10.1109/FCS.2015.7138839","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138839","url":null,"abstract":"This paper describes a method to verify received time telegrams distributed by Long Wave Radio systems for the example of the radio ripple control technology .In the given approach, the time between two time telegrams is continuously measured and compared with the time difference calculated from the time information contained in the telegrams. In other words, physical and logical information is compared. The physical time difference is directly calculated using the carrier frequency of the transmission system (for example: DCF49 transmission system uses a carrier frequency of 129.1 kHz with FSK modulation). A counter is clocked using the received carrier frequency of the system. The physical time difference between the transmissions of two time telegrams can be derived from the number of carrier cycles. The logical time difference is given by the content of the time telegrams. The comparison of physical and logical time differences is continuously verified to detect time jumps, which may appear during the transmission of time telegrams. Therefore, manipulated or delayed time telegrams can be accurately identified. This method can be applied without changing the time distribution protocol and it can be adapted to other time distribution services.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"105 1","pages":"270-275"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84439153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Link calibration or receiver calibration for accurate time transfer? 链路校准或接收机校准准确的时间传递?

时间频率公报 Pub Date : 2015-04-12 DOI: 10.1109/FCS.2015.7138830

Z. Jiang

引用次数: 5

A cavityless laser using cesium cell with 459 nm laser pumping 采用459nm激光泵浦的铯电池无腔激光器

时间频率公报 Pub Date : 2015-04-12 DOI: 10.1109/FCS.2015.7138920

Xiaobo Xue, D. Pan, Jingbiao Chen

引用次数: 4

Generating entanglement between atomic spins with low-noise probing of an optical cavity 利用光学腔的低噪声探测产生原子自旋之间的纠缠

时间频率公报 Pub Date : 2015-04-12 DOI: 10.1109/FCS.2015.7138857

K. Cox, J. Weiner, G. P. Greve, J. K. Thompson

{"title":"Generating entanglement between atomic spins with low-noise probing of an optical cavity","authors":"K. Cox, J. Weiner, G. P. Greve, J. K. Thompson","doi":"10.1109/FCS.2015.7138857","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138857","url":null,"abstract":"Atomic projection noise limits the ultimate precision of all atomic sensors, including clocks, inertial sensors, magnetometers, etc. The independent quantum collapse of N atoms into a definite state (for example spin up or down) leads to an uncertainty ΔθSQL = 1/√N in the estimate of the quantum phase accumulated during a Ramsey sequence or its many generalizations. This phase uncertainty is referred to as the standard quantum limit. Creating quantum entanglement between the N atoms can allow the atoms to partially cancel each other's quantum noise, leading to reduced noise in the phase estimate below the standard quantum limit. Recent experiments have demonstrated up to 10 dB of phase noise reduction relative to the SQL by making collective spin measurements. This is achieved by trapping laser-cooled Rb atoms in an optical cavity and precisely measuring the shift of the cavity resonance frequency by an amount that depends on the number of atoms in spin up. Detecting the probe light with high total efficiency reduces excess classical and quantum back-action of the probe. Here we discuss recent progress and a technique for reducing the relative frequency noise between the probe light and the optical cavity, a key requirement for further advances.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"37 1","pages":"351-356"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90954643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Manufacturability of highly doped aluminum nitride films 高掺杂氮化铝薄膜的可制造性

时间频率公报 Pub Date : 2015-04-12 DOI: 10.1109/FCS.2015.7138957

S. Mishin, Y. Oshmyansky

{"title":"Manufacturability of highly doped aluminum nitride films","authors":"S. Mishin, Y. Oshmyansky","doi":"10.1109/FCS.2015.7138957","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138957","url":null,"abstract":"There have been several investigations [1], [2], [3], that demonstrated benefits of adding dopants such as (Sc) or combination of other materials, like Zr/Mg for example, to the aluminum nitride (AlN) films in order to increase coupling coefficient (kt^2) of the Bulk Acoustic Wave (BAW) devices. For concentrations below 10% atomic Sc, it is possible to use a single composite target with a standard magnetron design [4]. Most R&D systems that performed initial investigations on AlScN films with high concentration of Sc dopant, used two separate targets with two separate magnetrons: one with pure Al and one with pure Sc with different applying power to compensate for the large difference in sputtering rates of the two materials and get stoichiometric composition. Unfortunately, depositing from two different targets is only viable for low volume R&D experiments. The system described in this article uses standard dual conical magnetron with AC deposition source. Targets are cut into multiple segments as shown in Figure 1 [5]. Based on simple geometry of target's surface, deposited film composition is proportional to the surface of specific pieces of target material. Unfortunately, Al is eroded at much higher rate than Sc at the same potential and same magnetic field. Over the target life, concentration of Sc increases in the deposited films. In order to maintain same Sc composition over the entire target life, it is necessary to vary magnetic field locally over the surface of the Al and Sc pieces to provide same erosion rate of Al vs. Sc at the same target potential. Adjusting magnetic field for each segment of both Al and Sc allows for constant deposited film composition over the entire target life solves this problem.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"76 4 1","pages":"777-782"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89224342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Feasibility study of proximity sensing by using a conventional airborne transducer 传统机载传感器近距离传感的可行性研究

时间频率公报 Pub Date : 2015-04-12 DOI: 10.1109/FCS.2015.7138899

Ken Yamada, Shu Agatsuma

引用次数: 0

Discovery of persistent ionospheric frequency shifts of a few Herz and impact on time and frequency transfer 电离层持续几赫兹频移的发现及其对时间和频率转移的影响

时间频率公报 Pub Date : 2015-04-12 DOI: 10.1109/FCS.2015.7138904

M. Underhill

引用次数: 6

1/f noise of quartz resonators: Measurements, modelization and comparison studies 石英谐振器的1/f噪声:测量、建模和比较研究

时间频率公报 Pub Date : 2015-04-12 DOI: 10.1109/FCS.2015.7138813

S. Fabrice, Devel Michel, Imbaud Joel, Bourquin Roger, Bakir Ahmed, Vuillemin Cedric, Ghosh Santunu, Abbe Philippe, V. David, Cibiel Gilles