Pub Date : 2012-05-21DOI: 10.1109/FCS.2012.6243724
M. Ivan, B. Dulmet, G. Martin, P. Abbé, L. Robert, S. Ballandras
This paper presents a new patent-pending micro-mechanical BAW resonant structure driven by electrostatic force. The devices are based on a one-port design with a 1 μm-thick electrostatic gap to superimpose a static bias voltage and a dynamic excitation to a silicon plate. Depending on the thickness of the standard silicon wafers, flexural or thickness-extensional (TE) modes can alternatively be driven, yielding a resonant frequency close to 68 kHz in flexural modes, and 10 MHz in TE modes. Modelling steps and experimental results are provided and compared for both kinds of modes. An application example of the flexural mode structure to gravimetric sensing is outlined.
{"title":"A new electrostatically-excited silicon structure for CMUT and TE-mode resonators and sensing applications","authors":"M. Ivan, B. Dulmet, G. Martin, P. Abbé, L. Robert, S. Ballandras","doi":"10.1109/FCS.2012.6243724","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243724","url":null,"abstract":"This paper presents a new patent-pending micro-mechanical BAW resonant structure driven by electrostatic force. The devices are based on a one-port design with a 1 μm-thick electrostatic gap to superimpose a static bias voltage and a dynamic excitation to a silicon plate. Depending on the thickness of the standard silicon wafers, flexural or thickness-extensional (TE) modes can alternatively be driven, yielding a resonant frequency close to 68 kHz in flexural modes, and 10 MHz in TE modes. Modelling steps and experimental results are provided and compared for both kinds of modes. An application example of the flexural mode structure to gravimetric sensing is outlined.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"98 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133719664","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.2012.6243720
T. Laroche, G. Martin, W. Daniau, S. Ballandras, J. Friedt, J. Leguen
The possibility to remotely control impedance changes using resonant devices operating in the 434-MHz-centered Industry-Scientific-Medical (ISM) is demonstrated in this paper. The proposed principle is based on acoustically coupled modes in compact Surface Acoustic Wave (SAW) structures in which one port is connected to the variable load, the other being connected to a Radio-Frequency (RF) antenna for wireless interrogation purpose. The operation of the proposed principle is illustrated using a longitudinally-coupled resonator filter on quartz for “On-Off” switch remote control. Other sensor architecture are discussed as a conclusion of this work.
{"title":"A coupled-mode filter structure for wireless transceiver-sensors using reactive loads","authors":"T. Laroche, G. Martin, W. Daniau, S. Ballandras, J. Friedt, J. Leguen","doi":"10.1109/FCS.2012.6243720","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243720","url":null,"abstract":"The possibility to remotely control impedance changes using resonant devices operating in the 434-MHz-centered Industry-Scientific-Medical (ISM) is demonstrated in this paper. The proposed principle is based on acoustically coupled modes in compact Surface Acoustic Wave (SAW) structures in which one port is connected to the variable load, the other being connected to a Radio-Frequency (RF) antenna for wireless interrogation purpose. The operation of the proposed principle is illustrated using a longitudinally-coupled resonator filter on quartz for “On-Off” switch remote control. Other sensor architecture are discussed as a conclusion of this work.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"121 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":"133995575","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.2012.6243608
Xu Yongliang, Li Wei, Y. Haibo
BPL long-wave time service system is a long-range radio time service system in China. Changhe II system is the most important land-based radio navigation system in China. China's satellite-based radio navigation system is in its construction and development stage now, so the Changhe II system will play an important role for a long time in the future. It will also exist as the important backup of the satellite-based radio navigation system. This paper presents the idea that take BPL long-wave time service station as one of the transmitter of Changhe II system. A mathematical model which can convert time difference obtained by the receiver into latitude-longitude coordinate is established. With effective configuration of the BPL station and the Changhe II transmitters, select points outside the coverage areas of the original system to locate its position in the simulation work. A test is also designed. The simulation and test results show that the scheme presented in this paper is feasible.
{"title":"The research on positioning using BPL station","authors":"Xu Yongliang, Li Wei, Y. Haibo","doi":"10.1109/FCS.2012.6243608","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243608","url":null,"abstract":"BPL long-wave time service system is a long-range radio time service system in China. Changhe II system is the most important land-based radio navigation system in China. China's satellite-based radio navigation system is in its construction and development stage now, so the Changhe II system will play an important role for a long time in the future. It will also exist as the important backup of the satellite-based radio navigation system. This paper presents the idea that take BPL long-wave time service station as one of the transmitter of Changhe II system. A mathematical model which can convert time difference obtained by the receiver into latitude-longitude coordinate is established. With effective configuration of the BPL station and the Changhe II transmitters, select points outside the coverage areas of the original system to locate its position in the simulation work. A test is also designed. The simulation and test results show that the scheme presented in this paper is feasible.","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":"124868156","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.2012.6243624
Ji Wang, Bo Liu, Jianke Du, T. Ma
As the core element of a quartz crystal resonator, the thickness-shear vibration frequency of a quartz crystal plate is always of great interest and top priority in the analysis and design. Because of the difficulty in solving plate equations with the consideration of two-dimensional configuration with free edges, the analysis of resonators is traditionally done with one-dimensional solutions based on the straight-crested wave assumption, which has been validated from earlier experiences and lately numerical analysis with the finite element method. In this study, we start with the known Mindlin plate equations for the thickness-shear vibrations of a rectangular quartz crystal plate with the consideration of flexural and thickness-shear modes. Through the separation of variables, we can obtain higher-order ordinary differential equations for the thickness-shear mode and obtain characteristic functions. The special boundary considerations of resonators with free edges are satisfied through the work of stress components of each individual mode. The method starts with the approximation in one direction, then the same procedure is performed in other direction. Eventually, iteration is taken for each direction until the vibration frequency solution is close to approximations from both directions. This is known as the extended Kantorovich method for vibrations of plates and solutions are accurate as compared with known results from the finite element analysis.
{"title":"Approximate frequencies of rectangular quartz plates vibrating at thickness-shear modes with free edges","authors":"Ji Wang, Bo Liu, Jianke Du, T. Ma","doi":"10.1109/FCS.2012.6243624","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243624","url":null,"abstract":"As the core element of a quartz crystal resonator, the thickness-shear vibration frequency of a quartz crystal plate is always of great interest and top priority in the analysis and design. Because of the difficulty in solving plate equations with the consideration of two-dimensional configuration with free edges, the analysis of resonators is traditionally done with one-dimensional solutions based on the straight-crested wave assumption, which has been validated from earlier experiences and lately numerical analysis with the finite element method. In this study, we start with the known Mindlin plate equations for the thickness-shear vibrations of a rectangular quartz crystal plate with the consideration of flexural and thickness-shear modes. Through the separation of variables, we can obtain higher-order ordinary differential equations for the thickness-shear mode and obtain characteristic functions. The special boundary considerations of resonators with free edges are satisfied through the work of stress components of each individual mode. The method starts with the approximation in one direction, then the same procedure is performed in other direction. Eventually, iteration is taken for each direction until the vibration frequency solution is close to approximations from both directions. This is known as the extended Kantorovich method for vibrations of plates and solutions are accurate as compared with known results from the finite element analysis.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"38 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":"114950842","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.2012.6243700
T. Cai, F. Josse, S. Heinrich, N. Nigro, I. Dufour, O. Brand
The resonant characteristics of rectangular microcantilevers vibrating in the torsional mode in viscous liquid media are investigated. The hydrodynamic load (torque per unit length) on the vibrating beam due to the liquid was first determined using a finite element model. An analytical expression of the hydrodynamic function in terms of the Reynolds number and aspect ratio, h/b (with thickness, h, and width, b) was then obtained by fitting the numerical results. This allowed for the resonance frequency and quality factor to be investigated as functions of both beam geometry and medium properties. Moreover, the effects of the aspect ratio on the cross-section's torsional constant, K, which affects the microcantilever's torsional stiffness, and on its polar moment of inertia, Jp, which is associated with the beam's rotational inertia, are also considered when obtaining the resonance frequency and quality factor. Compared with microcantilevers under out-of-plane (transverse) flexural vibration, the results show that microcantilevers that vibrate in their 1st torsional or 1st in-plane (lateral) flexural resonant modes have higher resonance frequency and quality factor. The increase in resonance frequency and quality factor results in higher mass sensitivity and reduced frequency noise, respectively. The improvement in the sensitivity and quality factor are expected to yield much lower limits of detection in liquid-phase chemical sensing applications.
{"title":"Resonant characteristics of rectangular microcantilevers vibrating torsionally in viscous liquid media","authors":"T. Cai, F. Josse, S. Heinrich, N. Nigro, I. Dufour, O. Brand","doi":"10.1109/FCS.2012.6243700","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243700","url":null,"abstract":"The resonant characteristics of rectangular microcantilevers vibrating in the torsional mode in viscous liquid media are investigated. The hydrodynamic load (torque per unit length) on the vibrating beam due to the liquid was first determined using a finite element model. An analytical expression of the hydrodynamic function in terms of the Reynolds number and aspect ratio, h/b (with thickness, h, and width, b) was then obtained by fitting the numerical results. This allowed for the resonance frequency and quality factor to be investigated as functions of both beam geometry and medium properties. Moreover, the effects of the aspect ratio on the cross-section's torsional constant, K, which affects the microcantilever's torsional stiffness, and on its polar moment of inertia, Jp, which is associated with the beam's rotational inertia, are also considered when obtaining the resonance frequency and quality factor. Compared with microcantilevers under out-of-plane (transverse) flexural vibration, the results show that microcantilevers that vibrate in their 1st torsional or 1st in-plane (lateral) flexural resonant modes have higher resonance frequency and quality factor. The increase in resonance frequency and quality factor results in higher mass sensitivity and reduced frequency noise, respectively. The improvement in the sensitivity and quality factor are expected to yield much lower limits of detection in liquid-phase chemical sensing applications.","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":"131333904","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.2012.6243674
D. Agrawal, J. Woodhouse, A. Seshia
The modelling of the non-linear behaviour of MEMS oscillators is of interest to understand the effects of non-linearities on start-up, limit cycle behaviour and performance metrics such as output frequency and phase noise. This paper proposes an approach to integrate the non-linear modelling of the resonator, transducer and sustaining amplifier in a single numerical modelling environment so that their combined effects may be investigated simultaneously. The paper validates the proposed electrical model of the resonator through open-loop frequency response measurements on an electrically addressed flexural silicon MEMS resonator driven to large motional amplitudes. A square wave oscillator is constructed by embedding the same resonator as the primary frequency determining element. Measurements of output power and output frequency of the square wave oscillator as a function of resonator bias and driving voltage are consistent with model predictions ensuring that the model captures the essential non-linear behaviour of the resonator and the sustaining amplifier in a single mathematical equation.
{"title":"Modelling non-linearities in a MEMS square wave oscillator","authors":"D. Agrawal, J. Woodhouse, A. Seshia","doi":"10.1109/FCS.2012.6243674","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243674","url":null,"abstract":"The modelling of the non-linear behaviour of MEMS oscillators is of interest to understand the effects of non-linearities on start-up, limit cycle behaviour and performance metrics such as output frequency and phase noise. This paper proposes an approach to integrate the non-linear modelling of the resonator, transducer and sustaining amplifier in a single numerical modelling environment so that their combined effects may be investigated simultaneously. The paper validates the proposed electrical model of the resonator through open-loop frequency response measurements on an electrically addressed flexural silicon MEMS resonator driven to large motional amplitudes. A square wave oscillator is constructed by embedding the same resonator as the primary frequency determining element. Measurements of output power and output frequency of the square wave oscillator as a function of resonator bias and driving voltage are consistent with model predictions ensuring that the model captures the essential non-linear behaviour of the resonator and the sustaining amplifier in a single mathematical equation.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"456 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120897478","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.2012.6243622
Yang Xuhai, Hu Zhenyuan, Guo Ji, L. Xiaohui, Li Zhigang, Y. Haibo
A new method of Common-view time transfer with transfer mode(TCV for abbreviation) via GEO telecommunication satellite is put forward, with which we can transfer the standard time kept in a time keeping laboratory, such as UTC (NTSC), to many users in the local area covered by the GEO satellite's signal. The time keeping laboratory is equipped with transmitting device and receiving device, and their external reference is from the main clock of the lab. The pseudo-code ranging signal is generated by the transmitting device in the lab, and is transmitted to the GEO satellite via a paraboloidal antenna, and then is broadcasted to the earth by the satellite. The pseudo-range from transmitter to GEO satellite and to the receiving device is measured in the lab. And at the same time the pseudo-range from transmitter to GEO satellite and to the user time receiver is also measured. By processing the pseudo-range measured by the user time receiver and that measured in the lab with paraboloidal antenna in common-view method, we can get the time difference between the user receiver clock and the main clock in the lab, carrying out the common-view time transfer with transfer mode (TCV). The precise coordinates of paraboloidal antenna in NTSC and the user time receiver, as well as precise orbit of the GEO satellite should be known in advance in this method. Chinese national standard time, UTC (NTSC) is kept in National Time Service Center (NTSC), Chinese Academy of Science. Based on the device of Two-Way Satellite Time and Frequency Transfer with C-band (TW(C) for abbreviation) in NTSC and Xinjiang Astronomical Observatory (XAO), we did TCV experiment. Both the transmitting and receiving units of the TW(C) device in NTSC are used, and only the receiving unit of the TW(C) device in XAO is used as a user time receiver. The main clock of UTC (NTSC) is a HP5071A Cs atomic clock, and an OSA5585 PRS Cs atomic clock is equipped in XAO. SATRE MODEM made by Timetech Company in Germany is used in our TW(C) devices and the code rate is 20MChips. The GEO satellite used in the experiment is Sinosat-1 telecommunication satellite (110.5°E). For the data processing in TCV method, the precise coordinates of the transmitting station and the receiving station are known in advance, the satellite orbit is provided by the Chinese Area Positioning System (CAPS) of Chinese Academy of Sciences, orbit precision is on the level of meter. And the system errors including Sagnac effect, ionosphere delay, troposphere delay etc, are taken out during the data processing, but the device delay is not deducted. We compare the results of TCV and TW(C), and it shows that ignoring the device delay (almost constant), the RMS of the difference between TCV and TW(C) is about 1ns for five consecutive days, and such result is very better than that in GPS Common-view time transfer with code.
{"title":"Method of common-view time transfer with transfer mode based on geostationary satellite","authors":"Yang Xuhai, Hu Zhenyuan, Guo Ji, L. Xiaohui, Li Zhigang, Y. Haibo","doi":"10.1109/FCS.2012.6243622","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243622","url":null,"abstract":"A new method of Common-view time transfer with transfer mode(TCV for abbreviation) via GEO telecommunication satellite is put forward, with which we can transfer the standard time kept in a time keeping laboratory, such as UTC (NTSC), to many users in the local area covered by the GEO satellite's signal. The time keeping laboratory is equipped with transmitting device and receiving device, and their external reference is from the main clock of the lab. The pseudo-code ranging signal is generated by the transmitting device in the lab, and is transmitted to the GEO satellite via a paraboloidal antenna, and then is broadcasted to the earth by the satellite. The pseudo-range from transmitter to GEO satellite and to the receiving device is measured in the lab. And at the same time the pseudo-range from transmitter to GEO satellite and to the user time receiver is also measured. By processing the pseudo-range measured by the user time receiver and that measured in the lab with paraboloidal antenna in common-view method, we can get the time difference between the user receiver clock and the main clock in the lab, carrying out the common-view time transfer with transfer mode (TCV). The precise coordinates of paraboloidal antenna in NTSC and the user time receiver, as well as precise orbit of the GEO satellite should be known in advance in this method. Chinese national standard time, UTC (NTSC) is kept in National Time Service Center (NTSC), Chinese Academy of Science. Based on the device of Two-Way Satellite Time and Frequency Transfer with C-band (TW(C) for abbreviation) in NTSC and Xinjiang Astronomical Observatory (XAO), we did TCV experiment. Both the transmitting and receiving units of the TW(C) device in NTSC are used, and only the receiving unit of the TW(C) device in XAO is used as a user time receiver. The main clock of UTC (NTSC) is a HP5071A Cs atomic clock, and an OSA5585 PRS Cs atomic clock is equipped in XAO. SATRE MODEM made by Timetech Company in Germany is used in our TW(C) devices and the code rate is 20MChips. The GEO satellite used in the experiment is Sinosat-1 telecommunication satellite (110.5°E). For the data processing in TCV method, the precise coordinates of the transmitting station and the receiving station are known in advance, the satellite orbit is provided by the Chinese Area Positioning System (CAPS) of Chinese Academy of Sciences, orbit precision is on the level of meter. And the system errors including Sagnac effect, ionosphere delay, troposphere delay etc, are taken out during the data processing, but the device delay is not deducted. We compare the results of TCV and TW(C), and it shows that ignoring the device delay (almost constant), the RMS of the difference between TCV and TW(C) is about 1ns for five consecutive days, and such result is very better than that in GPS Common-view time transfer with code.","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":"121044372","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.2012.6243620
S. Yazici, M. Giovannini, N. Kuo, G. Piazza
This paper reports on the application to 1 GHz AlN MEMS contour-mode resonators (CMR) of a spurious mode suppression technique based on the introduction of dummy electrodes and a method to shift the resonator center frequency by modifying its cavity size. The realization of wideband filters with CMRs is currently limited by the need to 1) enlarge the device capacitance (so as to minimize the inductive components in the matching network), 2) reduce in-band ripples and out-of-band spurs (which are introduced when the device capacitance is increased), and 3) shift the device center frequency by a large percentage (>; 2%) to synthesize ladder/lattice configurations. This work addresses these 3 main challenges by optimizing the electromechanical response of AlN CMRs having a large static capacitance, synthesized by using thin AlN films of two different thicknesses (500 nm and 1 μm thick), sandwiched by Pt and Al electrodes and having a large number of fingers (up to 45). 3D COMSOL finite element model is used to analyze and/predict the resonator's behavior.
{"title":"Suppression of spurious modes via dummy electrodes and 2% frequency shift via cavity size selection for 1 GHz AlN MEMS contour-mode resonators","authors":"S. Yazici, M. Giovannini, N. Kuo, G. Piazza","doi":"10.1109/FCS.2012.6243620","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243620","url":null,"abstract":"This paper reports on the application to 1 GHz AlN MEMS contour-mode resonators (CMR) of a spurious mode suppression technique based on the introduction of dummy electrodes and a method to shift the resonator center frequency by modifying its cavity size. The realization of wideband filters with CMRs is currently limited by the need to 1) enlarge the device capacitance (so as to minimize the inductive components in the matching network), 2) reduce in-band ripples and out-of-band spurs (which are introduced when the device capacitance is increased), and 3) shift the device center frequency by a large percentage (>; 2%) to synthesize ladder/lattice configurations. This work addresses these 3 main challenges by optimizing the electromechanical response of AlN CMRs having a large static capacitance, synthesized by using thin AlN films of two different thicknesses (500 nm and 1 μm thick), sandwiched by Pt and Al electrodes and having a large number of fingers (up to 45). 3D COMSOL finite element model is used to analyze and/predict the resonator's behavior.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"39 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":"121330297","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.2012.6243636
F. Fang, Weiliang Chen, Nianfeng Liu, Kun Liu, R. Suo, Ping Wang, Tian-chu Li
Several evaluations of the frequency shifts have been carried out after NIM5 was moved to the new NIM campus at Changping in 2011. The dominate frequency uncertainty was the microwave power related frequency shifts, which was mainly induced by the microwave leakage for NIM5. The experimental results show that fountains are more sensitive to the leakage field below the Ramsey cavity than above the cavity at the odd multiples of the optimal power. This effect can be reduced by trimming interferometric RF switch time, which makes atoms feel more symmetric leakage field during the ascending and the descending. The fractional frequency shift due to this effect is evaluated by alternatively running the NIM5 fountain between two timing modes. The overall uncertainty of NIM5 is smaller than 2e-15. The comparisons of NIM5 with other fountain clocks in 3 months are shown and consistent with this result.
{"title":"Microwave power related frequency shifts of NIM5","authors":"F. Fang, Weiliang Chen, Nianfeng Liu, Kun Liu, R. Suo, Ping Wang, Tian-chu Li","doi":"10.1109/FCS.2012.6243636","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243636","url":null,"abstract":"Several evaluations of the frequency shifts have been carried out after NIM5 was moved to the new NIM campus at Changping in 2011. The dominate frequency uncertainty was the microwave power related frequency shifts, which was mainly induced by the microwave leakage for NIM5. The experimental results show that fountains are more sensitive to the leakage field below the Ramsey cavity than above the cavity at the odd multiples of the optimal power. This effect can be reduced by trimming interferometric RF switch time, which makes atoms feel more symmetric leakage field during the ascending and the descending. The fractional frequency shift due to this effect is evaluated by alternatively running the NIM5 fountain between two timing modes. The overall uncertainty of NIM5 is smaller than 2e-15. The comparisons of NIM5 with other fountain clocks in 3 months are shown and consistent with this result.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"27 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":"125699885","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.2012.6243602
Jianwei Zhang, Zhengbo Wang, Shiguang Wang, K. Miao, Bo Wang, Lijun Wang
The progress towards to a microwave frequency standard based on laser-cooled 113Cd+ ions trapped in a linear quadrupole trap is reported. The experimental apparatus is introduced and the measurement of the clock transition is demonstrated. The estimated performance of the clock is also discussed.
{"title":"Progress towards a microwave frequency standard based on the laser cooled 113Cd+ ions","authors":"Jianwei Zhang, Zhengbo Wang, Shiguang Wang, K. Miao, Bo Wang, Lijun Wang","doi":"10.1109/FCS.2012.6243602","DOIUrl":"https://doi.org/10.1109/FCS.2012.6243602","url":null,"abstract":"The progress towards to a microwave frequency standard based on laser-cooled 113Cd+ ions trapped in a linear quadrupole trap is reported. The experimental apparatus is introduced and the measurement of the clock transition is demonstrated. The estimated performance of the clock is also discussed.","PeriodicalId":256670,"journal":{"name":"2012 IEEE International Frequency Control Symposium Proceedings","volume":"15 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":"125477552","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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