时间频率公报Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138950
T. Sun, Li Zhang, K. Receveur, A. Daryoush, A. Poddar, U. Rohde
{"title":"Comparison of self-ILPLL forced oscillators","authors":"T. Sun, Li Zhang, K. Receveur, A. Daryoush, A. Poddar, U. Rohde","doi":"10.1109/FCS.2015.7138950","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138950","url":null,"abstract":"Phase noise performance of oscillators using various forced oscillation using self-injection locked phase locked loop (SILPLL) configurations has been reported. Comparisons are made to identify the key parameters that have the most impact on phase noise.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"75 1","pages":"749-751"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77982623","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}
时间频率公报Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138802
S. Varadan, G. Pan, Zhao Zhao, T. Alford
{"title":"As-doped Si's complex permittivity and its effects on heating curve at 2.45 GHz frequency","authors":"S. Varadan, G. Pan, Zhao Zhao, T. Alford","doi":"10.1109/FCS.2015.7138802","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138802","url":null,"abstract":"An analysis to determine the complex permittivity of arsenic-doped silicon wafer at 2.45 GHz is presented based on closed-form analytical expressions for cylindrical symmetry. Experimental results in support with the numerical analysis and simulation results are also presented. This analysis will further help analyze the capacitive heating of doped and undoped silicon wafer at microwave frequency; hence, this paper is a precursor to elucidation of capacitive heating of silicon substrates placed between susceptors. This study indicates that when the dopant is added to the silicon the loss tangent decreases with increase in concentration but upon annealing the loss tangent becomes constant with respect to concentration of the dopant.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"13 1","pages":"111-116"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77326362","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}
时间频率公报Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138835
K. S. AlDawood
{"title":"SASO time scale and measurement capability","authors":"K. S. AlDawood","doi":"10.1109/FCS.2015.7138835","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138835","url":null,"abstract":"SASO Time and Frequency Laboratory is a responsible for national time scale generation and dissemination on Saudi Arabia. Recently at SASO NMCC the Time and Frequency Laboratory was developed using primary 5 Cs atomic clocks, 2 GNSS receivers and high technology modern equipments, The national time scale was generated with an uncertainty better than 2×10-14 and disseminated through the internet for industrial applications using an NTP time dissemination system with an uncertainty less than 50 ms. The fully automatic time and frequency calibration system that was developed is traceable to the national time scale and has the capability for frequency generation and measurement in the DC - 50 GHz range including signal analysis and phase noise measurements. Currently SASO is a member of BIPM Atomic Time Club in order to contribute to the Universal Coordinated Time (UTC) time scale and the realization of the international traceability of the SASO time scale.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"34 1","pages":"254-256"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73275360","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}
时间频率公报Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138824
M. Nagaraju, S. Sridaran, Andrew Lingley, J. Larson, B. Otis, R. Ruby
{"title":"Comparison of acoustic wave pressure sensors for TPMS applications","authors":"M. Nagaraju, S. Sridaran, Andrew Lingley, J. Larson, B. Otis, R. Ruby","doi":"10.1109/FCS.2015.7138824","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138824","url":null,"abstract":"We study and compare the pressure sensitivities of different area Rayleigh Lamb wave (RL) mode (S1 mode) and FBAR resonators. The studied RL-mode and FBAR resonators operate at 785MHz and 628MHz respectively. The resonators are fabricated on a released membrane with AlN as the piezoelectric layer. The resonators are hermetically sealed and the manufacturing process uses standard micromachining techniques throughout. The devices exhibit a pressure sensitivity over a range of 15 - 80psi, suitable for Tire Pressure Monitoring Systems (TPMS). The sensitivities of different area resonators are compared.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"34 3","pages":"205-208"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/FCS.2015.7138824","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72471078","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}
时间频率公报Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138855
M. Underhill
{"title":"SDR and Self-Focusing radar techniques for milliHerz measurement of multi-component phase noise spectra?","authors":"M. Underhill","doi":"10.1109/FCS.2015.7138855","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138855","url":null,"abstract":"Synthetic Aperture Radar (SAR) Self-Focusing post-processing techniques can be used for faster higher precision Phase Noise and Allan Variance measurement on more than one signal component at a time. Software Radio (SDR) techniques [1, 2] are used to sample, acquire decimate and process the signals, on a continuous basis, for record lengths of up to a few days and with resolution bandwidths down to a few milliHerz.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"50 1","pages":"343-346"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72912485","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}
时间频率公报Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138840
S. Ebenhag, M. Zelan, P. Hedekvist, M. Karlsson, Borje Josefsson
{"title":"Two-way coherent frequency transfer in a commercial DWDM communication network in Sweden","authors":"S. Ebenhag, M. Zelan, P. Hedekvist, M. Karlsson, Borje Josefsson","doi":"10.1109/FCS.2015.7138840","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138840","url":null,"abstract":"An experimental fiber link is being established between SP Technical Research Institute of Sweden in Borås and Chalmers University of Gothenburg in Sweden. The one way fiber length is about 60 km and implemented in SUNET (Swedish University Network). The aim of the project is to evaluate the signal quality when sending a stable optical frequency utilizing a wavelength in a DWDM (Dense Wavelength Division Multiplexing) system fiber pair. The experiment uses a channel in the DWDM with the wavelength of 1542.14 nm. This wavelength is within the C band and is therefore compatible with common Erbium doped amplifiers in this network. Another aim of the system is to be ultra-stable which corresponds to a stability of 1×10-13 for τ = 1 s as well as providing the ability to distribute monitored ultra-stable frequency with a future traceability to UTC (SP) (National realization of Universal Time Coordinated within Sweden) to multiple users within the network. Measurements of an optical frequency transfer using a fiber-link based on unidirectional light signals in parallel fibers have shown promising results in a free-running setup and in a lab environment. The fractional frequency stability, analyzed as the Overlapping Allan deviation, is approximately 3×10-13 at τ = 10 s and almost 1×10-14 at 105 s.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"6 1","pages":"276-279"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77310997","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}
时间频率公报Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138909
A. Novick, M. Lombardi
{"title":"Practical limitations of NTP time transfer","authors":"A. Novick, M. Lombardi","doi":"10.1109/FCS.2015.7138909","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138909","url":null,"abstract":"The Network Time Protocol (NTP) is commonly utilized to synchronize computer clocks in packet-switched, wide area networks (WANs) such as the public Internet. The delay asymmetry in WANs, often due to inconsistent routing and/or bandwidth saturation, is usually the dominant source of error. It typically limits NTP time transfer uncertainty to about one millisecond. This paper discusses the uncertainty of NTP time transfer when network asymmetry is largely eliminated. We performed NTP measurements over a local area network (LAN) when both the server and client are referenced to a common clock. Three variations of a LAN are tested, including a direct connection between the server and client with an Ethernet crossover cable. The elimination of network asymmetry reveals other uncertainty sources that serve as practical limitations for NTP time transfer, including client instability, asymmetry in network interface cards, and server instability.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"23 1","pages":"570-574"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85610561","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}
时间频率公报Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138911
Clivati Cecilia, Calonico Davide, Frittelli Matteo, M. Alberto, Levi Filippo
{"title":"A fiber link for the remote comparison of optical clocks and geodesy experiments","authors":"Clivati Cecilia, Calonico Davide, Frittelli Matteo, M. Alberto, Levi Filippo","doi":"10.1109/FCS.2015.7138911","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138911","url":null,"abstract":"Differential comparisons of distant optical clocks with uncertainties in the 10-18 level linked by phase-stabilized optical fibers can be used to probe the Geoid potential at the centimeter sensitivity. Here, we present the realization and characterization of a coherent optical link that will enable gravitational potential measurements on a baseline of 90km and at 1000m of difference in altitude. This is a proof-of-principle experiment that aims at exploring extensive interconnections between geodesy and frequency metrology.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"273 1","pages":"579-582"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76815001","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}
时间频率公报Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138956
Guiling Wu, Liang Hu, Hao Zhang, Jianping Chen
{"title":"A round-trip fiber-optic time transfer system using bidirectional TDM transmission","authors":"Guiling Wu, Liang Hu, Hao Zhang, Jianping Chen","doi":"10.1109/FCS.2015.7138956","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138956","url":null,"abstract":"We propose a round-trip fiber-optic time transfer scheme over single optical fiber utilizing the same wavelength in both directions. It can suppress the impact of the Rayleigh backscattering and the dispersion-induced symmetric deviation over fiber link by using bidirectional time division multiplexing (TDM) mechanism. A 200 km time transfer over single optical fiber with identical optical wavelength in both directions is demonstrated. The measured stabilities in terms of TDEV are less than 40ps/s and 10ps/d, respectively. The uncertainty induced by uncalibrated fiber links up to 200km is less than 27 ps, which is mainly limited by the performance of used time interval counters.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"64 1","pages":"773-776"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77226385","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}
时间频率公报Pub Date : 2015-04-12DOI: 10.2991/ICECEE-15.2015.155
Tao Liu, Yonghui Hu, Yu Hua, Haifeng Jiang
{"title":"Study on autonomous and distributed time synchronization method for formation UAVs","authors":"Tao Liu, Yonghui Hu, Yu Hua, Haifeng Jiang","doi":"10.2991/ICECEE-15.2015.155","DOIUrl":"https://doi.org/10.2991/ICECEE-15.2015.155","url":null,"abstract":"In order to implement high precision time synchronization autonomously in the absence of any external time source, in this paper, the author introduced the synchronize model of fireflies into UAV formation network, and proposed a kind of distributed time synchronization method base on broadcast, and conducted some computer simulation experiments and built one test platform to prove the feasibility of the method and its performance, the results show that the method can effectively achieve time synchronization autonomously without any external time source, and the synchronization accuracy can be achieved about 50us.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"26 1","pages":"293-296"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90884725","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}