Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138939
G. Hummel, M. Rinaldi
This work presents the first experimental demonstration of an intrinsically switchable Aluminum Nitride (AlN) 2-port MEMS resonator using 3 monolithically integrated chalcogenide phase change material (PCM) switches.
{"title":"Switchable 2-port Aluminum Nitride MEMS resonator using monolithically integrated 3.6 THz cut-off frequency phase-change switches","authors":"G. Hummel, M. Rinaldi","doi":"10.1109/FCS.2015.7138939","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138939","url":null,"abstract":"This work presents the first experimental demonstration of an intrinsically switchable Aluminum Nitride (AlN) 2-port MEMS resonator using 3 monolithically integrated chalcogenide phase change material (PCM) switches.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"12 1","pages":"706-708"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79088377","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 : 2015-04-12DOI: 10.1109/FCS.2015.7138839
Schneider Matthias, Ruland Christoph
This paper describes a method to verify received time telegrams distributed by Long Wave Radio systems for the example of the radio ripple control technology .In the given approach, the time between two time telegrams is continuously measured and compared with the time difference calculated from the time information contained in the telegrams. In other words, physical and logical information is compared. The physical time difference is directly calculated using the carrier frequency of the transmission system (for example: DCF49 transmission system uses a carrier frequency of 129.1 kHz with FSK modulation). A counter is clocked using the received carrier frequency of the system. The physical time difference between the transmissions of two time telegrams can be derived from the number of carrier cycles. The logical time difference is given by the content of the time telegrams. The comparison of physical and logical time differences is continuously verified to detect time jumps, which may appear during the transmission of time telegrams. Therefore, manipulated or delayed time telegrams can be accurately identified. This method can be applied without changing the time distribution protocol and it can be adapted to other time distribution services.
{"title":"Verification of time telegrams in Long Wave Radio systems","authors":"Schneider Matthias, Ruland Christoph","doi":"10.1109/FCS.2015.7138839","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138839","url":null,"abstract":"This paper describes a method to verify received time telegrams distributed by Long Wave Radio systems for the example of the radio ripple control technology .In the given approach, the time between two time telegrams is continuously measured and compared with the time difference calculated from the time information contained in the telegrams. In other words, physical and logical information is compared. The physical time difference is directly calculated using the carrier frequency of the transmission system (for example: DCF49 transmission system uses a carrier frequency of 129.1 kHz with FSK modulation). A counter is clocked using the received carrier frequency of the system. The physical time difference between the transmissions of two time telegrams can be derived from the number of carrier cycles. The logical time difference is given by the content of the time telegrams. The comparison of physical and logical time differences is continuously verified to detect time jumps, which may appear during the transmission of time telegrams. Therefore, manipulated or delayed time telegrams can be accurately identified. This method can be applied without changing the time distribution protocol and it can be adapted to other time distribution services.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"105 1","pages":"270-275"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84439153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138830
Z. Jiang
In almost all the studies, the differential receiver calibration and the link calibration had been discussed separately as if the two calibrations were completely independent. In fact, in the sense of the total delay for UTC time transfer, the difference between the receiver and link calibrations is not how to perform the calibration measurement but how to use the measurement data. The two calibration results are convertible to each other under certain condition. We discuss the features, advantages and disadvantages of the link and receiver calibrations, their uncertainties, and in particular, their applications in the computation of [UTC-UTC(k)].
{"title":"Link calibration or receiver calibration for accurate time transfer?","authors":"Z. Jiang","doi":"10.1109/FCS.2015.7138830","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138830","url":null,"abstract":"In almost all the studies, the differential receiver calibration and the link calibration had been discussed separately as if the two calibrations were completely independent. In fact, in the sense of the total delay for UTC time transfer, the difference between the receiver and link calibrations is not how to perform the calibration measurement but how to use the measurement data. The two calibration results are convertible to each other under certain condition. We discuss the features, advantages and disadvantages of the link and receiver calibrations, their uncertainties, and in particular, their applications in the computation of [UTC-UTC(k)].","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"PP 1","pages":"230-235"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84605356","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 : 2015-04-12DOI: 10.1109/FCS.2015.7138920
Xiaobo Xue, D. Pan, Jingbiao Chen
In this paper, we present a laser scheme without cavity in a 10 cm cesium cell as a potential active optical frequency standard. Since no cavity is applied, the stimulated light is emitted from the atoms directly and the center frequency of output laser light is solely determined by atoms without cavity pulling. The threshold characteristic of the emitted light is measured. This scheme can be used to investigate the relation between stimulated emission and amplified spontaneous emission. It is expected to be further extended to generate other narrow linewidth frequency standard signals.
{"title":"A cavityless laser using cesium cell with 459 nm laser pumping","authors":"Xiaobo Xue, D. Pan, Jingbiao Chen","doi":"10.1109/FCS.2015.7138920","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138920","url":null,"abstract":"In this paper, we present a laser scheme without cavity in a 10 cm cesium cell as a potential active optical frequency standard. Since no cavity is applied, the stimulated light is emitted from the atoms directly and the center frequency of output laser light is solely determined by atoms without cavity pulling. The threshold characteristic of the emitted light is measured. This scheme can be used to investigate the relation between stimulated emission and amplified spontaneous emission. It is expected to be further extended to generate other narrow linewidth frequency standard signals.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"17 1","pages":"614-617"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85256630","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 : 2015-04-12DOI: 10.1109/FCS.2015.7138857
K. Cox, J. Weiner, G. P. Greve, J. K. Thompson
Atomic projection noise limits the ultimate precision of all atomic sensors, including clocks, inertial sensors, magnetometers, etc. The independent quantum collapse of N atoms into a definite state (for example spin up or down) leads to an uncertainty ΔθSQL = 1/√N in the estimate of the quantum phase accumulated during a Ramsey sequence or its many generalizations. This phase uncertainty is referred to as the standard quantum limit. Creating quantum entanglement between the N atoms can allow the atoms to partially cancel each other's quantum noise, leading to reduced noise in the phase estimate below the standard quantum limit. Recent experiments have demonstrated up to 10 dB of phase noise reduction relative to the SQL by making collective spin measurements. This is achieved by trapping laser-cooled Rb atoms in an optical cavity and precisely measuring the shift of the cavity resonance frequency by an amount that depends on the number of atoms in spin up. Detecting the probe light with high total efficiency reduces excess classical and quantum back-action of the probe. Here we discuss recent progress and a technique for reducing the relative frequency noise between the probe light and the optical cavity, a key requirement for further advances.
{"title":"Generating entanglement between atomic spins with low-noise probing of an optical cavity","authors":"K. Cox, J. Weiner, G. P. Greve, J. K. Thompson","doi":"10.1109/FCS.2015.7138857","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138857","url":null,"abstract":"Atomic projection noise limits the ultimate precision of all atomic sensors, including clocks, inertial sensors, magnetometers, etc. The independent quantum collapse of N atoms into a definite state (for example spin up or down) leads to an uncertainty ΔθSQL = 1/√N in the estimate of the quantum phase accumulated during a Ramsey sequence or its many generalizations. This phase uncertainty is referred to as the standard quantum limit. Creating quantum entanglement between the N atoms can allow the atoms to partially cancel each other's quantum noise, leading to reduced noise in the phase estimate below the standard quantum limit. Recent experiments have demonstrated up to 10 dB of phase noise reduction relative to the SQL by making collective spin measurements. This is achieved by trapping laser-cooled Rb atoms in an optical cavity and precisely measuring the shift of the cavity resonance frequency by an amount that depends on the number of atoms in spin up. Detecting the probe light with high total efficiency reduces excess classical and quantum back-action of the probe. Here we discuss recent progress and a technique for reducing the relative frequency noise between the probe light and the optical cavity, a key requirement for further advances.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"37 1","pages":"351-356"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90954643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138957
S. Mishin, Y. Oshmyansky
There have been several investigations [1], [2], [3], that demonstrated benefits of adding dopants such as (Sc) or combination of other materials, like Zr/Mg for example, to the aluminum nitride (AlN) films in order to increase coupling coefficient (kt^2) of the Bulk Acoustic Wave (BAW) devices. For concentrations below 10% atomic Sc, it is possible to use a single composite target with a standard magnetron design [4]. Most R&D systems that performed initial investigations on AlScN films with high concentration of Sc dopant, used two separate targets with two separate magnetrons: one with pure Al and one with pure Sc with different applying power to compensate for the large difference in sputtering rates of the two materials and get stoichiometric composition. Unfortunately, depositing from two different targets is only viable for low volume R&D experiments. The system described in this article uses standard dual conical magnetron with AC deposition source. Targets are cut into multiple segments as shown in Figure 1 [5]. Based on simple geometry of target's surface, deposited film composition is proportional to the surface of specific pieces of target material. Unfortunately, Al is eroded at much higher rate than Sc at the same potential and same magnetic field. Over the target life, concentration of Sc increases in the deposited films. In order to maintain same Sc composition over the entire target life, it is necessary to vary magnetic field locally over the surface of the Al and Sc pieces to provide same erosion rate of Al vs. Sc at the same target potential. Adjusting magnetic field for each segment of both Al and Sc allows for constant deposited film composition over the entire target life solves this problem.
{"title":"Manufacturability of highly doped aluminum nitride films","authors":"S. Mishin, Y. Oshmyansky","doi":"10.1109/FCS.2015.7138957","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138957","url":null,"abstract":"There have been several investigations [1], [2], [3], that demonstrated benefits of adding dopants such as (Sc) or combination of other materials, like Zr/Mg for example, to the aluminum nitride (AlN) films in order to increase coupling coefficient (kt^2) of the Bulk Acoustic Wave (BAW) devices. For concentrations below 10% atomic Sc, it is possible to use a single composite target with a standard magnetron design [4]. Most R&D systems that performed initial investigations on AlScN films with high concentration of Sc dopant, used two separate targets with two separate magnetrons: one with pure Al and one with pure Sc with different applying power to compensate for the large difference in sputtering rates of the two materials and get stoichiometric composition. Unfortunately, depositing from two different targets is only viable for low volume R&D experiments. The system described in this article uses standard dual conical magnetron with AC deposition source. Targets are cut into multiple segments as shown in Figure 1 [5]. Based on simple geometry of target's surface, deposited film composition is proportional to the surface of specific pieces of target material. Unfortunately, Al is eroded at much higher rate than Sc at the same potential and same magnetic field. Over the target life, concentration of Sc increases in the deposited films. In order to maintain same Sc composition over the entire target life, it is necessary to vary magnetic field locally over the surface of the Al and Sc pieces to provide same erosion rate of Al vs. Sc at the same target potential. Adjusting magnetic field for each segment of both Al and Sc allows for constant deposited film composition over the entire target life solves this problem.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"76 4 1","pages":"777-782"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89224342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138899
Ken Yamada, Shu Agatsuma
Ultrasonic proximity sensors utilizing non-radiant (evanescent) acoustic fields created in the vicinity of piezoelectric vibrators were proposed. When an object is brought into the evanescent field, electric admittance of the vibrator varies depending on the vibrator-to-object distance. In former reports, the air-film damping effect occurred between the sensing plate attached to the length-extensional mode vibrator and the test-object plate was studied. In this study, the sensing system is constructed by using a commercially-available airborne transducer. Distance dependent variation in the electric admittance level such as that observed in the former study has been confirmed.
{"title":"Feasibility study of proximity sensing by using a conventional airborne transducer","authors":"Ken Yamada, Shu Agatsuma","doi":"10.1109/FCS.2015.7138899","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138899","url":null,"abstract":"Ultrasonic proximity sensors utilizing non-radiant (evanescent) acoustic fields created in the vicinity of piezoelectric vibrators were proposed. When an object is brought into the evanescent field, electric admittance of the vibrator varies depending on the vibrator-to-object distance. In former reports, the air-film damping effect occurred between the sensing plate attached to the length-extensional mode vibrator and the test-object plate was studied. In this study, the sensing system is constructed by using a commercially-available airborne transducer. Distance dependent variation in the electric admittance level such as that observed in the former study has been confirmed.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"8 1","pages":"528-529"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87394336","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 : 2015-04-12DOI: 10.1109/FCS.2015.7138904
M. Underhill
Unexpected frequency shifts and occasional splitting of short-wave Standard Frequency Signals into components with persistent frequency shifts of up to a Herz or so have been `discovered' using SDR receivers with milliHerz resolution. Such spurious signals have also been observed on AM carrier frequencies and DRM signals between ~1MHz and 25MHz. The frequency shifts are in general downwards like `Hubble' shifts but at times can be upwards, depending on the time of day and direction of the path around the earth. Shifted components in general correlate with the existence of an ionospheric propagation path. At some times an unwanted frequency shifted component can be stronger than the original carrier signal and then the Standard Frequency Signal cannot be used as an accurate reference frequency. There are also problems with inaccurate pirate standard frequency signal transmissions on some frequencies. Small short term, diurnal and seasonal frequency variations are being investigated as a possible method of detecting gravity waves.
{"title":"Discovery of persistent ionospheric frequency shifts of a few Herz and impact on time and frequency transfer","authors":"M. Underhill","doi":"10.1109/FCS.2015.7138904","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138904","url":null,"abstract":"Unexpected frequency shifts and occasional splitting of short-wave Standard Frequency Signals into components with persistent frequency shifts of up to a Herz or so have been `discovered' using SDR receivers with milliHerz resolution. Such spurious signals have also been observed on AM carrier frequencies and DRM signals between ~1MHz and 25MHz. The frequency shifts are in general downwards like `Hubble' shifts but at times can be upwards, depending on the time of day and direction of the path around the earth. Shifted components in general correlate with the existence of an ionospheric propagation path. At some times an unwanted frequency shifted component can be stronger than the original carrier signal and then the Standard Frequency Signal cannot be used as an accurate reference frequency. There are also problems with inaccurate pirate standard frequency signal transmissions on some frequencies. Small short term, diurnal and seasonal frequency variations are being investigated as a possible method of detecting gravity waves.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"174 1","pages":"549-552"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76924421","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 : 2015-04-12DOI: 10.1109/FCS.2015.7138813
S. Fabrice, Devel Michel, Imbaud Joel, Bourquin Roger, Bakir Ahmed, Vuillemin Cedric, Ghosh Santunu, Abbe Philippe, V. David, Cibiel Gilles
In this paper, the description of the resonator realization and the topology of the resonator prototype is exposed. Phase noise measurements of a hundred of resonators are given. The noise results are discussed according to the position of the resonators inside the crystal block and physical analysis of the crystal (dislocation). The results are also compared according to their Q-factors measured at room temperature and at low temperature. Theoretically, the fluctuation-dissipation theorem is used in order to put numerical constraints on a model of 1/f noise caused by an internal (or structural) dissipation proportional to the amplitude and not to the speed. The order of magnitude of the noise is then discussed.
{"title":"1/f noise of quartz resonators: Measurements, modelization and comparison studies","authors":"S. Fabrice, Devel Michel, Imbaud Joel, Bourquin Roger, Bakir Ahmed, Vuillemin Cedric, Ghosh Santunu, Abbe Philippe, V. David, Cibiel Gilles","doi":"10.1109/FCS.2015.7138813","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138813","url":null,"abstract":"In this paper, the description of the resonator realization and the topology of the resonator prototype is exposed. Phase noise measurements of a hundred of resonators are given. The noise results are discussed according to the position of the resonators inside the crystal block and physical analysis of the crystal (dislocation). The results are also compared according to their Q-factors measured at room temperature and at low temperature. Theoretically, the fluctuation-dissipation theorem is used in order to put numerical constraints on a model of 1/f noise caused by an internal (or structural) dissipation proportional to the amplitude and not to the speed. The order of magnitude of the noise is then discussed.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"13 1","pages":"158-161"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79573151","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 : 2015-04-12DOI: 10.1109/FCS.2015.7138863
Y. Almleaky, Alaa Almleaky, Hamzah Almleaky, Samy Khadem-Al-Charieh
In this work we will present the Makkah timescale generation, its setup and changes over time. As a special challenge the Makkah Time Scale is located in two labs, which are connected with a zero delay system via a 200m glass fibre. Having a new type of time interval counters, we compared measurements of performances and capabilities.
{"title":"Makkah timescale generation and measurement capability","authors":"Y. Almleaky, Alaa Almleaky, Hamzah Almleaky, Samy Khadem-Al-Charieh","doi":"10.1109/FCS.2015.7138863","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138863","url":null,"abstract":"In this work we will present the Makkah timescale generation, its setup and changes over time. As a special challenge the Makkah Time Scale is located in two labs, which are connected with a zero delay system via a 200m glass fibre. Having a new type of time interval counters, we compared measurements of performances and capabilities.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"130 1","pages":"384-387"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77204492","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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