Pub Date : 2001-06-06DOI: 10.1109/FREQ.2001.956332
H. Fang, J.S. Yang
The flexural vibration of an elastic beam with surface bonded piezoelectric films rotating about its axis is studied. One-dimensional equations governing the motion of the beam are developed, including the effects of Coriolis and centrifugal forces. The equations are employed in the analysis of the flexural vibration of the beam under the excitation of an alternating electric voltage. Forced vibration solution is obtained. It is shown that the beam can be used as a gyroscope for detecting the angular rate of the rotation. Voltage sensitivity and its dependence on various geometric and physical parameters are examined.
{"title":"Vibration analysis of a rotating elastic beam with piezoelectric films as an angular rate sensor","authors":"H. Fang, J.S. Yang","doi":"10.1109/FREQ.2001.956332","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956332","url":null,"abstract":"The flexural vibration of an elastic beam with surface bonded piezoelectric films rotating about its axis is studied. One-dimensional equations governing the motion of the beam are developed, including the effects of Coriolis and centrifugal forces. The equations are employed in the analysis of the flexural vibration of the beam under the excitation of an alternating electric voltage. Forced vibration solution is obtained. It is shown that the beam can be used as a gyroscope for detecting the angular rate of the rotation. Voltage sensitivity and its dependence on various geometric and physical parameters are examined.","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124937064","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 : 2001-06-06DOI: 10.1109/FREQ.2001.956159
Thomas B. Swanson, Eric A. Burt, C. Ekstrom
We have performed an initial characterization of the stability of the U.S. Naval Observatory (USNO) cesium fountain atomic clock. This device has a short-term fractional frequency stability of up to 1.5/spl times/10/sup -13/ /spl tau/-/sup 1/2/. This short-term performance enables us to measure hydrogen maser behavior over the short to medium term. We have recently implemented real time steering of a hydrogen maser with the fountain. Over a period of roughly 9 days of continuous operation, we have steered out the drift of a cavity tuned maser.
{"title":"Characterization of the USNO cesium fountain","authors":"Thomas B. Swanson, Eric A. Burt, C. Ekstrom","doi":"10.1109/FREQ.2001.956159","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956159","url":null,"abstract":"We have performed an initial characterization of the stability of the U.S. Naval Observatory (USNO) cesium fountain atomic clock. This device has a short-term fractional frequency stability of up to 1.5/spl times/10/sup -13/ /spl tau/-/sup 1/2/. This short-term performance enables us to measure hydrogen maser behavior over the short to medium term. We have recently implemented real time steering of a hydrogen maser with the fountain. Over a period of roughly 9 days of continuous operation, we have steered out the drift of a cavity tuned maser.","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122406602","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 : 2001-06-06DOI: 10.1109/FREQ.2001.956362
Mitsunori Dendal, Y. Yong
The two-dimensional time-harmonic Boundary Element Method (BEM) for the general anisotropy is presented and applied to the eigen frequency analysis of quartz resonators. The use of the time-harmonic fundamental solution provides a clean boundary only formulation of the BEM without domain integrals. The resulting eigenvalue problem, given by a full matrix with each element depending nonlinearly on the frequency, is reduced to a generalized linear eigenvalue problem, which is solved by the QZ algorithm. Numerical results are presented for eigenvalue analysis of quartz and compared with existing FEM and analytical solutions. The proposed BEM equals or surpasses the performance of the FEM in its accuracy.
{"title":"2-D time-harmonic BEM for general anisotropy applied to eigenvalue analysis of quartz resonators","authors":"Mitsunori Dendal, Y. Yong","doi":"10.1109/FREQ.2001.956362","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956362","url":null,"abstract":"The two-dimensional time-harmonic Boundary Element Method (BEM) for the general anisotropy is presented and applied to the eigen frequency analysis of quartz resonators. The use of the time-harmonic fundamental solution provides a clean boundary only formulation of the BEM without domain integrals. The resulting eigenvalue problem, given by a full matrix with each element depending nonlinearly on the frequency, is reduced to a generalized linear eigenvalue problem, which is solved by the QZ algorithm. Numerical results are presented for eigenvalue analysis of quartz and compared with existing FEM and analytical solutions. The proposed BEM equals or surpasses the performance of the FEM in its accuracy.","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132558741","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 : 2001-06-06DOI: 10.1109/FREQ.2001.956173
E. Ivanov, L. Hollberg, S. Diddams
The goal this work was to study the limitations imposed on frequency stability of synthesised optical signal by intrinsic fluctuations of the femtosecond laser as well as fluctuations in the optical readout system.
本工作的目的是研究飞秒激光的固有波动以及光学读出系统的波动对合成光信号频率稳定性的限制。
{"title":"Experimental study of noise properties of a Ti-sapphire mode-locked laser","authors":"E. Ivanov, L. Hollberg, S. Diddams","doi":"10.1109/FREQ.2001.956173","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956173","url":null,"abstract":"The goal this work was to study the limitations imposed on frequency stability of synthesised optical signal by intrinsic fluctuations of the femtosecond laser as well as fluctuations in the optical readout system.","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130313870","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 : 2001-06-06DOI: 10.1109/FREQ.2001.956208
A. Halperin
Quartz usually contains AI impurities substituted for silicon in the lattice, with monovalent ions, as charge compensators at the Al. Ionizing radiation was found to induce frequency shifts in quartz resonators, caused by the migration in the lattice of the monovalent ions. Thermoluminescence was used in the present work to investigate the migration of the monovalent ions, Li/sup +/ in the present work. The investigation suggested a way to transfer the Li ions from the Al to sites where they form thermally stable electron traps. They are then not available for migration in the lattice. Irradiation at 350 K was found to reduce the concentration of the Li ions available for migration by two orders of magnitude.
{"title":"Elimination of radiation induced frequency-shifts caused by migration of alkali-metal ions in quartz","authors":"A. Halperin","doi":"10.1109/FREQ.2001.956208","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956208","url":null,"abstract":"Quartz usually contains AI impurities substituted for silicon in the lattice, with monovalent ions, as charge compensators at the Al. Ionizing radiation was found to induce frequency shifts in quartz resonators, caused by the migration in the lattice of the monovalent ions. Thermoluminescence was used in the present work to investigate the migration of the monovalent ions, Li/sup +/ in the present work. The investigation suggested a way to transfer the Li ions from the Al to sites where they form thermally stable electron traps. They are then not available for migration in the lattice. Irradiation at 350 K was found to reduce the concentration of the Li ions available for migration by two orders of magnitude.","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114480966","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 : 2001-06-06DOI: 10.1109/FREQ.2001.956352
T. Pastureaud, V. Laude, A. Soufyane, S. Ballandras
Two approaches are investigated to model accurately the physical characteristics of plate mode devices, and more particularly of resonators. They are respectively based on finite element analysis (FEA) and on mixing FEA with a boundary integral method (FEA/BIM). In the later case, using a transfer matrix approach for the computation of the spectral Green's function results in numerical instabilities for large layer thickness or large slowness. A new stable algorithm is described for the computation of the spectral Green's function of a multilayer structure, that is inherently numerically stable. The main parameters of wave propagation (velocity, coupling factor, reflection coefficient) can then be estimated considering an infinite periodic structure and computing the harmonic admittance. For comparison with measurements of quartz transverse plate mode resonators, the estimated parameters can be inserted in a P-matrix model. Theory and experiments are found to comply well for both the pure FEA and the FEA/BIM approaches.
{"title":"Stabilization of the simulation of saw devices on stratified structures: application to transverse plate mode resonators","authors":"T. Pastureaud, V. Laude, A. Soufyane, S. Ballandras","doi":"10.1109/FREQ.2001.956352","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956352","url":null,"abstract":"Two approaches are investigated to model accurately the physical characteristics of plate mode devices, and more particularly of resonators. They are respectively based on finite element analysis (FEA) and on mixing FEA with a boundary integral method (FEA/BIM). In the later case, using a transfer matrix approach for the computation of the spectral Green's function results in numerical instabilities for large layer thickness or large slowness. A new stable algorithm is described for the computation of the spectral Green's function of a multilayer structure, that is inherently numerically stable. The main parameters of wave propagation (velocity, coupling factor, reflection coefficient) can then be estimated considering an infinite periodic structure and computing the harmonic admittance. For comparison with measurements of quartz transverse plate mode resonators, the estimated parameters can be inserted in a P-matrix model. Theory and experiments are found to comply well for both the pure FEA and the FEA/BIM approaches.","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121867337","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 : 2001-06-06DOI: 10.1109/FREQ.2001.956260
K. Wessendorf
This unique bridge-type oscillator design permits liquid-loaded operation of QCM (quartz crystal microbalance) resonators with a simple, low parts count and inexpensive oscillator. This is achieved using "active-bridge" operation, which eliminates the need for the expensive and complex ALC (automatic level control) circuits typically used in high-performance oscillators designed for these applications. The Active-Bridge oscillator absorbs the wide dynamic range of resonator loss by varying the circuit operating Q as a function of the resonator loss. The output amplitude is relatively proportional to resonator loss. This design has demonstrated the ability to servo a loaded QCM resonator to within a few degrees of zero impedance-phase over a wide range of resonator loss, 300 /spl Omega/ to approximately 3k /spl Omega/. This corresponds roughly to a liquid viscosity range of 1 to 120 cP, assuming a density close to one.
{"title":"The active-bridge oscillator for use with liquid loaded QCM sensors","authors":"K. Wessendorf","doi":"10.1109/FREQ.2001.956260","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956260","url":null,"abstract":"This unique bridge-type oscillator design permits liquid-loaded operation of QCM (quartz crystal microbalance) resonators with a simple, low parts count and inexpensive oscillator. This is achieved using \"active-bridge\" operation, which eliminates the need for the expensive and complex ALC (automatic level control) circuits typically used in high-performance oscillators designed for these applications. The Active-Bridge oscillator absorbs the wide dynamic range of resonator loss by varying the circuit operating Q as a function of the resonator loss. The output amplitude is relatively proportional to resonator loss. This design has demonstrated the ability to servo a loaded QCM resonator to within a few degrees of zero impedance-phase over a wide range of resonator loss, 300 /spl Omega/ to approximately 3k /spl Omega/. This corresponds roughly to a liquid viscosity range of 1 to 120 cP, assuming a density close to one.","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121878461","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 : 2001-06-06DOI: 10.1109/FREQ.2001.956387
V. Stofanik, Igor Balaz, M. Minárik
A a direct digital frequency synthesizer incorporating compensation of frequency versus temperature (f-T) dependency of reference crystal oscillator is presented. The frequency instability of the synthesizer is /spl plusmn/0.1 ppm in a wide temperature range (-40/spl deg/C to +85/spl deg/C).
{"title":"Digitally temperature compensated DDS","authors":"V. Stofanik, Igor Balaz, M. Minárik","doi":"10.1109/FREQ.2001.956387","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956387","url":null,"abstract":"A a direct digital frequency synthesizer incorporating compensation of frequency versus temperature (f-T) dependency of reference crystal oscillator is presented. The frequency instability of the synthesizer is /spl plusmn/0.1 ppm in a wide temperature range (-40/spl deg/C to +85/spl deg/C).","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"118 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126140251","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 : 2001-06-06DOI: 10.1109/FREQ.2001.956287
O. Bel, R. Bourquin
In a perfect vibrating beam gyrometer the sensing mode of vibration is only excited by the Coriolis effect and it is assumed that the sensing electrodes do not respond to the primary mode of vibration. This is the case if the shape of the vibrating beam and of the electrodes don't exhibit geometric defects. In this paper we consider, in a practical point of view, the effect of geometrical defects, like misalignment, of electrodes. These defects can induce a non zero output signal (called the bias) when the gyrometer doesn't rotate and, in a less part, an alteration of the scale factor. We restrict our attention to small defects, which induce only a small dissymmetry of electrodes with respect to the symmetric axis of the beam. The method used to compute the amplitude of vibration, as well as the output current, needs to determine the static electric field in the cross section of the sensor. To do that we use an approximated method based on the decomposition of the electric potential in Fourier series. Although we here consider a tuning fork device, all what is presented is obviously valid for a single beam rate sensor.
{"title":"Effect of geometrical electrode defects on the bias and sensitivity of tuning fork angular rate sensor","authors":"O. Bel, R. Bourquin","doi":"10.1109/FREQ.2001.956287","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956287","url":null,"abstract":"In a perfect vibrating beam gyrometer the sensing mode of vibration is only excited by the Coriolis effect and it is assumed that the sensing electrodes do not respond to the primary mode of vibration. This is the case if the shape of the vibrating beam and of the electrodes don't exhibit geometric defects. In this paper we consider, in a practical point of view, the effect of geometrical defects, like misalignment, of electrodes. These defects can induce a non zero output signal (called the bias) when the gyrometer doesn't rotate and, in a less part, an alteration of the scale factor. We restrict our attention to small defects, which induce only a small dissymmetry of electrodes with respect to the symmetric axis of the beam. The method used to compute the amplitude of vibration, as well as the output current, needs to determine the static electric field in the cross section of the sensor. To do that we use an approximated method based on the decomposition of the electric potential in Fourier series. Although we here consider a tuning fork device, all what is presented is obviously valid for a single beam rate sensor.","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128906559","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 : 2001-06-06DOI: 10.1109/FREQ.2001.956164
W. Nagourney
We feel that continuing advancement of the state of the art of single ion trapping and laser technology will make a single laser-cooled ion a viable candidate for a time or frequency standard in the very near future. The recent achievements in flywheel laser technology and the use of femtosecond "comb" lasers to bridge the optical-microwave gap are very important steps in this direction. These advances together with the well-known advantages of,an optical frequency and small systematics should make the prospects for a single-ion optical standard very favorable indeed.
{"title":"Optical time and frequency standard based on single indium ion","authors":"W. Nagourney","doi":"10.1109/FREQ.2001.956164","DOIUrl":"https://doi.org/10.1109/FREQ.2001.956164","url":null,"abstract":"We feel that continuing advancement of the state of the art of single ion trapping and laser technology will make a single laser-cooled ion a viable candidate for a time or frequency standard in the very near future. The recent achievements in flywheel laser technology and the use of femtosecond \"comb\" lasers to bridge the optical-microwave gap are very important steps in this direction. These advances together with the well-known advantages of,an optical frequency and small systematics should make the prospects for a single-ion optical standard very favorable indeed.","PeriodicalId":369101,"journal":{"name":"Proceedings of the 2001 IEEE International Frequncy Control Symposium and PDA Exhibition (Cat. No.01CH37218)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116474786","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：