Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243591
B. Wang, C. Gao, W. L. Chen, J. Miao, Y. Bai, T. Li, L. J. Wang
We build up a time and frequency dissemination system via the 80 km urban telecommunication fiber network between Tsinghua university (THU) and the National Institute of Metrology (NIM). A 9.1 GHz microwave frequency is disseminated on this link. Using the proposed phase noise compensation method, the frequency dissemination stability on the order of 7 × 10-15/s and 4.5 × 10-19/105 s has been demonstrated. In addition, we also disseminate the timing signal between THU and NIM. Using the delay time compensation method, transfer delay stability within 50 ps at measurement periods from 1s to 1000s has been demonstrated.
{"title":"Fiber-based time and frequency dissemination between THU and NIM","authors":"B. Wang, C. Gao, W. L. Chen, J. Miao, Y. Bai, T. Li, L. J. Wang","doi":"10.1109/FCS.2012.6243591","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243591","url":null,"abstract":"We build up a time and frequency dissemination system via the 80 km urban telecommunication fiber network between Tsinghua university (THU) and the National Institute of Metrology (NIM). A 9.1 GHz microwave frequency is disseminated on this link. Using the proposed phase noise compensation method, the frequency dissemination stability on the order of 7 × 10-15/s and 4.5 × 10-19/105 s has been demonstrated. In addition, we also disseminate the timing signal between THU and NIM. Using the delay time compensation method, transfer delay stability within 50 ps at measurement periods from 1s to 1000s has been demonstrated.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128495580","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}
Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243713
T. Pensala, M. Prunnila, A. Jaakkola
The effect of degenerate level n-type doping on the bulk acoustic wave propagation properties in single crystal silicon is studied. Keyes' theory [1] is used to calculate the electronic effect of free electrons on the elastic constants cij as function of temperature. Slowness curves are calculated for the bulk acoustic wave modes via solution of the Christoffel equation at several doping levels. Variation with respect to temperature is performed in order to extract the linear temperature coefficient of slowness as function of propagation direction. It is found that n-type doping has the largest effect on the slow shear mode and that temperature stable wave propagation directions exist with doping levels above 1019 cm-3. Comparison to experiment is made via measured temperature coefficients of frequency of square plate resonators vibrating in the Lamé mode which is a pure superposition of shear bulk acoustic waves. Good agreement is found.
{"title":"Bulk acoustic wave propagation characteristics in degenerately n-doped Si","authors":"T. Pensala, M. Prunnila, A. Jaakkola","doi":"10.1109/FCS.2012.6243713","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243713","url":null,"abstract":"The effect of degenerate level n-type doping on the bulk acoustic wave propagation properties in single crystal silicon is studied. Keyes' theory [1] is used to calculate the electronic effect of free electrons on the elastic constants cij as function of temperature. Slowness curves are calculated for the bulk acoustic wave modes via solution of the Christoffel equation at several doping levels. Variation with respect to temperature is performed in order to extract the linear temperature coefficient of slowness as function of propagation direction. It is found that n-type doping has the largest effect on the slow shear mode and that temperature stable wave propagation directions exist with doping levels above 1019 cm-3. Comparison to experiment is made via measured temperature coefficients of frequency of square plate resonators vibrating in the Lamé mode which is a pure superposition of shear bulk acoustic waves. Good agreement is found.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129624711","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}
Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243633
S. Kazmi, T. Aarnink, C. Salm, J. Schmitz
This paper reports on the fabrication, simulation and characterization of post processing compatible poly GeSi MEM resonators. The resonators are fabricated, following a two masks process flow, using 1.5 μm thick low stress, highly conductive in-situ boron doped LPCVD poly Ge0.7Si0.3 structural layers. All the process steps are kept below 450°C to potentially avoid CMOS degradation, a prime concern for post processing compatible MEMS. A narrow gap of ~40 nm is achieved using a sacrificial gap oxide layer between the vibrating structure and the electrodes. The GeSi resonators, square plate and circular disk, are excited in their respective Lamé and Wine glass modes exhibiting the resonance peaks at 47.9 MHz and 72.77 MHz, respectively, with the quality factor around 200,000 in air, the highest reported till date for post processing compatible capacitively transduced resonators.
{"title":"CMOS-MEMS post processing compatible capacitively transduced GeSi resonators","authors":"S. Kazmi, T. Aarnink, C. Salm, J. Schmitz","doi":"10.1109/FCS.2012.6243633","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243633","url":null,"abstract":"This paper reports on the fabrication, simulation and characterization of post processing compatible poly GeSi MEM resonators. The resonators are fabricated, following a two masks process flow, using 1.5 μm thick low stress, highly conductive in-situ boron doped LPCVD poly Ge0.7Si0.3 structural layers. All the process steps are kept below 450°C to potentially avoid CMOS degradation, a prime concern for post processing compatible MEMS. A narrow gap of ~40 nm is achieved using a sacrificial gap oxide layer between the vibrating structure and the electrodes. The GeSi resonators, square plate and circular disk, are excited in their respective Lamé and Wine glass modes exhibiting the resonance peaks at 47.9 MHz and 72.77 MHz, respectively, with the quality factor around 200,000 in air, the highest reported till date for post processing compatible capacitively transduced resonators.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127072380","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}
Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243688
H. Katori, M. Takamoto, T. Takano, I. Ushijima, Takuya Ohkubo, K. Yamanaka, N. Ohmae, Y. Aso, A. Shoda, T. Ushiba, P. Thoumany, Manoj Das, B. R. Christensen, T. Akatsuka
We are developing optical lattice clocks with a scope of attaining 10-18 fractional uncertainty. Cryogenic silicon cavity targeting 2×10-17 stability at 1s, will allow full utilization of the potential stability of optical lattice clocks. In order to reduce the blackbody radiation shift, which is the most serious source of uncertainties, Sr clocks in cryogenic environment and Hg clocks are underdevelopment. We discuss prospects for clock comparison, no dead time operation of the clocks and fiber link of the clocks between Riken and the University of Tokyo.
{"title":"Prospects for frequency comparison of Sr and Hg optical lattice clocks toward 10−18 uncertainties","authors":"H. Katori, M. Takamoto, T. Takano, I. Ushijima, Takuya Ohkubo, K. Yamanaka, N. Ohmae, Y. Aso, A. Shoda, T. Ushiba, P. Thoumany, Manoj Das, B. R. Christensen, T. Akatsuka","doi":"10.1109/FCS.2012.6243688","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243688","url":null,"abstract":"We are developing optical lattice clocks with a scope of attaining 10-18 fractional uncertainty. Cryogenic silicon cavity targeting 2×10-17 stability at 1s, will allow full utilization of the potential stability of optical lattice clocks. In order to reduce the blackbody radiation shift, which is the most serious source of uncertainties, Sr clocks in cryogenic environment and Hg clocks are underdevelopment. We discuss prospects for clock comparison, no dead time operation of the clocks and fiber link of the clocks between Riken and the University of Tokyo.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129091202","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}
Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243666
R. Smíd, M. Čížek, Z. Buchta, J. Lazar, O. Cíp
The ultra low expansion cavities play a crucial role in laser stabilization, and they are essential in ion clocks. We present a method to measure changes in the distance between mirrors of a Fabry-Perot cavity (FPC) with a spacer from an ultra low expansion material caused by temperature variation with femtometer resolution. The FPC was placed into a temperature-stabilized vacuum stainless steel chamber.
{"title":"Long-term measurement of ultra-low expansion Fabry-Perot cavity in stabilized temperature","authors":"R. Smíd, M. Čížek, Z. Buchta, J. Lazar, O. Cíp","doi":"10.1109/FCS.2012.6243666","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243666","url":null,"abstract":"The ultra low expansion cavities play a crucial role in laser stabilization, and they are essential in ion clocks. We present a method to measure changes in the distance between mirrors of a Fabry-Perot cavity (FPC) with a spacer from an ultra low expansion material caused by temperature variation with femtometer resolution. The FPC was placed into a temperature-stabilized vacuum stainless steel chamber.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126440007","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}
Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243681
J. Everard
This paper reviews simplified models and theories which use simple transfer function techniques (at the operating frequency) to accurately predict the phase noise in both feedback and negative resistance oscillators. These theories are then used to produce some key topologies, design rules and circuits for oscillators. A discussion of a regenerative divider which produces ¾ and 2/3 of the imput frequency is then described. The paper finishes with a description of a one day short course on Low Phase Noise Oscillators, which includes a laboratory class with 5 experiments. This has been presented at the IEEE International Microwave Symposium in 2009, 2010 and 2011.
{"title":"Low phase noise signal generation; Models and theory; Oscillators and their key elements; Fractional regenerative frequency division; Teaching","authors":"J. Everard","doi":"10.1109/FCS.2012.6243681","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243681","url":null,"abstract":"This paper reviews simplified models and theories which use simple transfer function techniques (at the operating frequency) to accurately predict the phase noise in both feedback and negative resistance oscillators. These theories are then used to produce some key topologies, design rules and circuits for oscillators. A discussion of a regenerative divider which produces ¾ and 2/3 of the imput frequency is then described. The paper finishes with a description of a one day short course on Low Phase Noise Oscillators, which includes a laboratory class with 5 experiments. This has been presented at the IEEE International Microwave Symposium in 2009, 2010 and 2011.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121296111","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}
Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243600
Y. Ishii, K. Kobayashi, T. Kobata, M. Ito, S. Watanabe, S. Sato, K. Akaike
This paper reports on a development and tests of the DSP-OCXO (Digital Signal Processing-Oven Controlled Crystal Oscillator) using AT cut crystal high accuracy temperature sensor which consisting of two thermal equivalent crystals. For the applications of the small size base stations, the DSP-OCXO which has following features: 14 × 9 mm small size, 0.6 W maximum at +25°C low power consumption and +/-20 ppb maximum /-40 to +85°C high frequency stability vs. temperature has been developed.
{"title":"A new generation DSP-OCXO using crystal temperature sensor","authors":"Y. Ishii, K. Kobayashi, T. Kobata, M. Ito, S. Watanabe, S. Sato, K. Akaike","doi":"10.1109/FCS.2012.6243600","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243600","url":null,"abstract":"This paper reports on a development and tests of the DSP-OCXO (Digital Signal Processing-Oven Controlled Crystal Oscillator) using AT cut crystal high accuracy temperature sensor which consisting of two thermal equivalent crystals. For the applications of the small size base stations, the DSP-OCXO which has following features: 14 × 9 mm small size, 0.6 W maximum at +25°C low power consumption and +/-20 ppb maximum /-40 to +85°C high frequency stability vs. temperature has been developed.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115287487","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}
Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243645
Li Wei, Yongliang Xu, Y. Haibo
In general, GEO satellite is used retransmit the signal in two-way time synchronous system. Keeping synchronous motion with earth, the satellite swing slightly, which have effect on the performance of two-way time synchronization. We can analyze the error caused by satellite movement from two aspects, including time synchronization error between stations, and distance difference from stations to satellite. This document analyzes and calculates the errors of two-way time synchronization cause by the two aspects. In addition, the same work is done when the IGSO satellite is used as retransmission satellite. The effect of satellite movement on two-way time synchronization performance has close relationship with the performance and motion mode of satellite.
{"title":"The effect of satellite movement on two-way time synchronization performance","authors":"Li Wei, Yongliang Xu, Y. Haibo","doi":"10.1109/FCS.2012.6243645","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243645","url":null,"abstract":"In general, GEO satellite is used retransmit the signal in two-way time synchronous system. Keeping synchronous motion with earth, the satellite swing slightly, which have effect on the performance of two-way time synchronization. We can analyze the error caused by satellite movement from two aspects, including time synchronization error between stations, and distance difference from stations to satellite. This document analyzes and calculates the errors of two-way time synchronization cause by the two aspects. In addition, the same work is done when the IGSO satellite is used as retransmission satellite. The effect of satellite movement on two-way time synchronization performance has close relationship with the performance and motion mode of satellite.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121820098","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}
Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243631
Sawsen Azaizia, Khaldoun Saleh, Olivier Llopis, A. Rissons
Various fiber optics links are evaluated for the transmission of OCXO signals on relatively short distances (1 m to 1 km). The case of VCSEL lasers is compared to the case of the more classical DFB laser. The DFB is still the best device, particularly in terms of signal to noise ratio, but single-mode VCSELs are becoming interesting as a low cost alternative to this device.
{"title":"Evaluation of low cost solutions for the transmission through optical fiber of low phase noise OCXO signals","authors":"Sawsen Azaizia, Khaldoun Saleh, Olivier Llopis, A. Rissons","doi":"10.1109/FCS.2012.6243631","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243631","url":null,"abstract":"Various fiber optics links are evaluated for the transmission of OCXO signals on relatively short distances (1 m to 1 km). The case of VCSEL lasers is compared to the case of the more classical DFB laser. The DFB is still the best device, particularly in terms of signal to noise ratio, but single-mode VCSELs are becoming interesting as a low cost alternative to this device.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132832292","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}
Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243604
J. Humphries, D. Malocha
Surface acoustic wave (SAW) technology, when paired with orthogonal frequency coding (OFC), has proven to be a versatile platform for the design of passive, wireless sensors. This paper presents the design and demonstration of a passive, wireless SAW strain sensor that is uniquely identifiable in a multi-sensor system. A cantilever fabricated out of the SAW substrate acts as the strain sensing mechanism. Force applied at the end of the cantilever causes a strain distribution at the root of the beam. In turn, a measurable change in the SAW propagation delay occurs between the SAW transducer and OFC reflector bank. Relating SAW propagation delay changes to strain is accomplished by developing a simple 1-D model. This model assumes strain in only the Z direction (YZ-LiNbO3) which allows the stiffness matrix to be ignored and an effective stiffness constant to be used instead. Derivations for strain coefficient as well as the strain and force equations needed to measure strain are given. The sensor test setup and experimental results are detailed and discussed. Additionally, a magnetic field sensor is demonstrated as an application for this design.
{"title":"Passive, wireless SAW OFC strain sensor","authors":"J. Humphries, D. Malocha","doi":"10.1109/FCS.2012.6243604","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243604","url":null,"abstract":"Surface acoustic wave (SAW) technology, when paired with orthogonal frequency coding (OFC), has proven to be a versatile platform for the design of passive, wireless sensors. This paper presents the design and demonstration of a passive, wireless SAW strain sensor that is uniquely identifiable in a multi-sensor system. A cantilever fabricated out of the SAW substrate acts as the strain sensing mechanism. Force applied at the end of the cantilever causes a strain distribution at the root of the beam. In turn, a measurable change in the SAW propagation delay occurs between the SAW transducer and OFC reflector bank. Relating SAW propagation delay changes to strain is accomplished by developing a simple 1-D model. This model assumes strain in only the Z direction (YZ-LiNbO3) which allows the stiffness matrix to be ignored and an effective stiffness constant to be used instead. Derivations for strain coefficient as well as the strain and force equations needed to measure strain are given. The sensor test setup and experimental results are detailed and discussed. Additionally, a magnetic field sensor is demonstrated as an application for this design.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133648052","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}
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