Pub Date : 2015-07-02DOI: 10.1109/FCS.2015.7138905
Hang Yi, Hongbo Wang, Shengkang Zhang, Haifeng Wang, F. Shi, Huaiying Shang, J. Ge, Yujie Yang, Zhiqi Li
With the development of BeiDou(BD) Navigation Satellite system, BD can be another choice for remote precise time and frequency transfer. A strict common view test using BD Navigation Satellite System is carried out in this paper. Since there are GEO, IGSO and MEO satellites in BD Navigation Satellite system, common view based on GEO, IGSO and MEO are discussed in this paper separately. Finally, we give a different weight to each satellite according to its elevation, and get a weighted-average common-view result which is better than 5 ns.
{"title":"Research on time and frequency transfer based on BeiDou common view","authors":"Hang Yi, Hongbo Wang, Shengkang Zhang, Haifeng Wang, F. Shi, Huaiying Shang, J. Ge, Yujie Yang, Zhiqi Li","doi":"10.1109/FCS.2015.7138905","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138905","url":null,"abstract":"With the development of BeiDou(BD) Navigation Satellite system, BD can be another choice for remote precise time and frequency transfer. A strict common view test using BD Navigation Satellite System is carried out in this paper. Since there are GEO, IGSO and MEO satellites in BD Navigation Satellite system, common view based on GEO, IGSO and MEO are discussed in this paper separately. Finally, we give a different weight to each satellite according to its elevation, and get a weighted-average common-view result which is better than 5 ns.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"42 1","pages":"553-556"},"PeriodicalIF":0.0,"publicationDate":"2015-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88740867","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 : 2015-07-02DOI: 10.1109/FCS.2015.7138916
Yanyan Zhang, Lulu Yan, S. Fan, Long Zhang, Wenyu Zhao, Wenge Guo, Shougang Zhang, Haifeng Jiang
We report the research progress of an erbium-fiber-based optical frequency comb with repetition rate 232 MHz. Its repetition rate is stabilized to a continuous wave laser via an intra-cavity electro-optic modulator and a piezo-transducer, yielding an in-loop frequency instability about 2.1×10-16 @ 1s. The carrier envelope offset (CEO) frequency with a signal-to-noise ratio of 45 dB for 300 kHz resolution spectrum is detected by using a common path f-2f interferometer. CEO frequency is locked to a RF reference frequency by controlling the pump current. The frequency instability induced by in-loop CEO frequency is about 2.9×10-16@ 1s. The frequency count in use is a Π-type counter from K&K.
{"title":"Development of an erbium-fiber-laser-based optical frequency comb at NTSC","authors":"Yanyan Zhang, Lulu Yan, S. Fan, Long Zhang, Wenyu Zhao, Wenge Guo, Shougang Zhang, Haifeng Jiang","doi":"10.1109/FCS.2015.7138916","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138916","url":null,"abstract":"We report the research progress of an erbium-fiber-based optical frequency comb with repetition rate 232 MHz. Its repetition rate is stabilized to a continuous wave laser via an intra-cavity electro-optic modulator and a piezo-transducer, yielding an in-loop frequency instability about 2.1×10-16 @ 1s. The carrier envelope offset (CEO) frequency with a signal-to-noise ratio of 45 dB for 300 kHz resolution spectrum is detected by using a common path f-2f interferometer. CEO frequency is locked to a RF reference frequency by controlling the pump current. The frequency instability induced by in-loop CEO frequency is about 2.9×10-16@ 1s. The frequency count in use is a Π-type counter from K&K.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"11 1","pages":"599-601"},"PeriodicalIF":0.0,"publicationDate":"2015-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81317216","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 : 2015-07-02DOI: 10.1109/FCS.2015.7138934
Caligaris Massimo, G. Costanzo, C. Calosso
Nowadays, in primary time and frequency laboratories we can find high spectral purity signals in the 10 MHz - 10 GHz range generated from cryogenic oscillators or ultra-stable lasers together with frequency combs. Their short-term stability surpasses by one to two orders of magnitude the performances of active hydrogen masers (AHM), while in the long-term AHMs still have a better behavior. The new technology can be considered mature for what concern spectral purity, but we cannot say the same about complexity, power consumption and reliability. In this sense, it is important to measure ultra-stable sources with respect to AHMs. First, to test their spectral purity or, at least, to give it an upper bound; second to have a continuous monitoring; finally, to combine them in order to get the best of all in term of phase noise and frequency stability. All of these requirements can be satisfied by the system we are developing. It is a multi-channel synchronous and real-time phasemeter based on Tracking Direct Digital Synthesizer (TDDS) technique. The results related to the first prototype are presented.
{"title":"6/12-channel synchronous digital phasemeter for ultrastable signal characterization and use","authors":"Caligaris Massimo, G. Costanzo, C. Calosso","doi":"10.1109/FCS.2015.7138934","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138934","url":null,"abstract":"Nowadays, in primary time and frequency laboratories we can find high spectral purity signals in the 10 MHz - 10 GHz range generated from cryogenic oscillators or ultra-stable lasers together with frequency combs. Their short-term stability surpasses by one to two orders of magnitude the performances of active hydrogen masers (AHM), while in the long-term AHMs still have a better behavior. The new technology can be considered mature for what concern spectral purity, but we cannot say the same about complexity, power consumption and reliability. In this sense, it is important to measure ultra-stable sources with respect to AHMs. First, to test their spectral purity or, at least, to give it an upper bound; second to have a continuous monitoring; finally, to combine them in order to get the best of all in term of phase noise and frequency stability. All of these requirements can be satisfied by the system we are developing. It is a multi-channel synchronous and real-time phasemeter based on Tracking Direct Digital Synthesizer (TDDS) technique. The results related to the first prototype are presented.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"11 1","pages":"681-683"},"PeriodicalIF":0.0,"publicationDate":"2015-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85191813","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 : 2015-07-02DOI: 10.1109/FCS.2015.7138906
F. Meynadier, P. Delva, Christophe le Poncin-Laffite, C. Guerlin, P. Laurent, P. Wolf
The Atomic Clocks Ensemble in Space (ACESPHARAO mission [1]) will realize, on board of the International Space Station, a time scale of very high stability and accuracy, connected to a dedicated microwave link (MWL) for comparison to ground clocks. This will allow to perform high performance time transfers between distant ground stations, as well as fundamental physics tests, such as measuring the gravitational redshift with unprecedented accuracy, and search for a violation of the Lorentz local invariance. Our team at SYRTE is currently developing a dedicated software for analyzing the data retrieved by the MWL. It will be a crucial component of the processing chain, allowing to reach the nominal scientific performances, thus complementing the quicklook data provided by the ground segment. During ACES flight, our software will run in a data processing center that will be set up in SYRTE, and process data as requested by IWG (ACES Investigator Working Group) request. We will present the current status of the data analysis software and its expected capabilities, mostly based on data generated by our own data simulator, but also some preliminary results of comparisons with actual test data from the instruments. Our simulator itself will also be presented, as it plays a key role in the validation of the data analysis software, and also allows to assert the sensitivity of ACES data to various theoretical signatures.
{"title":"Preparing ACES-PHARAO data analysis","authors":"F. Meynadier, P. Delva, Christophe le Poncin-Laffite, C. Guerlin, P. Laurent, P. Wolf","doi":"10.1109/FCS.2015.7138906","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138906","url":null,"abstract":"The Atomic Clocks Ensemble in Space (ACESPHARAO mission [1]) will realize, on board of the International Space Station, a time scale of very high stability and accuracy, connected to a dedicated microwave link (MWL) for comparison to ground clocks. This will allow to perform high performance time transfers between distant ground stations, as well as fundamental physics tests, such as measuring the gravitational redshift with unprecedented accuracy, and search for a violation of the Lorentz local invariance. Our team at SYRTE is currently developing a dedicated software for analyzing the data retrieved by the MWL. It will be a crucial component of the processing chain, allowing to reach the nominal scientific performances, thus complementing the quicklook data provided by the ground segment. During ACES flight, our software will run in a data processing center that will be set up in SYRTE, and process data as requested by IWG (ACES Investigator Working Group) request. We will present the current status of the data analysis software and its expected capabilities, mostly based on data generated by our own data simulator, but also some preliminary results of comparisons with actual test data from the instruments. Our simulator itself will also be presented, as it plays a key role in the validation of the data analysis software, and also allows to assert the sensitivity of ACES data to various theoretical signatures.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"2 1","pages":"557-561"},"PeriodicalIF":0.0,"publicationDate":"2015-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90414711","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.2015.7138945
T. Parker, T. H. Heavner, S. Jefferts
Primary frequency standards serve the function of calibrating the rate of International Atomic Time, TAI, and therefore play a critical role in the accuracy of the world's time. The Working Group on Primary and Secondary Frequency Standards, WGPSFS, is an advisory body to the Time Department of the Bureau International des Poids et Mesures and to the Consultative Committee for Time and Frequency on matters related to primary and secondary frequency standards that are used to determine the rate of TAI. A current issue being considered by the WGPSFS is establishing guidelines for deciding when and how to make corrections for newly discovered frequency biases in primary frequency standards. This paper is intended to generate discussions on this topic in an audience wider than just the WGPSFS.
{"title":"Bias corrections in primary frequency standards","authors":"T. Parker, T. H. Heavner, S. Jefferts","doi":"10.1109/FCS.2015.7138945","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138945","url":null,"abstract":"Primary frequency standards serve the function of calibrating the rate of International Atomic Time, TAI, and therefore play a critical role in the accuracy of the world's time. The Working Group on Primary and Secondary Frequency Standards, WGPSFS, is an advisory body to the Time Department of the Bureau International des Poids et Mesures and to the Consultative Committee for Time and Frequency on matters related to primary and secondary frequency standards that are used to determine the rate of TAI. A current issue being considered by the WGPSFS is establishing guidelines for deciding when and how to make corrections for newly discovered frequency biases in primary frequency standards. This paper is intended to generate discussions on this topic in an audience wider than just the WGPSFS.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"76 1","pages":"733-735"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73842763","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.2015.7138810
J. R. Jensen, G. Weaver
The New Horizons mission has provided an unprecedented opportunity to observe the evolution two ultra-stable oscillators in deep space for over nine years. The unusual architecture of the New Horizons communications system allows for direct observation of one of the two USOs during every tracking pass. The communications system is based on a transceiver as opposed to the normal transponder. The downlink is independent of the uplink in this architecture and so the USO is solely responsible for the downlink carrier frequency. Both USOs have greatly stabilized during the nine years of flight and have recently changed the direction of the frequency drift. The history since launch in January 2006 and the recent drift history are presented and discussed.
{"title":"Frequency performance of the New Horizons ultra-stable oscillators nine years of continuous in-flight monitoring","authors":"J. R. Jensen, G. Weaver","doi":"10.1109/FCS.2015.7138810","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138810","url":null,"abstract":"The New Horizons mission has provided an unprecedented opportunity to observe the evolution two ultra-stable oscillators in deep space for over nine years. The unusual architecture of the New Horizons communications system allows for direct observation of one of the two USOs during every tracking pass. The communications system is based on a transceiver as opposed to the normal transponder. The downlink is independent of the uplink in this architecture and so the USO is solely responsible for the downlink carrier frequency. Both USOs have greatly stabilized during the nine years of flight and have recently changed the direction of the frequency drift. The history since launch in January 2006 and the recent drift history are presented and discussed.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"60 1","pages":"145-150"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75629427","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.2015.7138803
V. Felmetsger, M. Mikhov, M. DeMiguel-Ramos, M. Clement, J. Olivares, T. Mirea, E. Iborra
In this work, we describe a sputter technique enabling deposition of AlScN thin films with homogeneous thickness and composition on production size wafers (150-200 mm) and present some preliminary results on the assessment of the structural and piezoelectric properties of the films with Sc content of about 6.5 at.%. The technique is based on the use of pure Sc ingots embedded into the Al targets of the dual-target S-gun magnetron enabling reactive sputtering with high radial thickness and composition homogeneity. Rutherford backscattering spectrometry was carried out to obtain the film composition. The microstructure and morphology were assessed by X-ray diffraction. Density was determined by X-ray grazing angle reflectometry. Electroacoustic properties and dielectric constant were derived from the frequency response of BAW test resonators. 1 μm-thick films showed wurtzite structure with pure c-axis orientation and rocking curves of the (00·2) diffraction peak with FWHM as low as 1.5°. Film properties appear to be uniform across 150-mm wafers. The material electromechanical coupling factor reached 9%, although the sound velocity of longitudinal mode was relatively low (around 8500 m/s).
{"title":"Sputtered Al(1−x)ScxN thin films with high areal uniformity for mass production","authors":"V. Felmetsger, M. Mikhov, M. DeMiguel-Ramos, M. Clement, J. Olivares, T. Mirea, E. Iborra","doi":"10.1109/FCS.2015.7138803","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138803","url":null,"abstract":"In this work, we describe a sputter technique enabling deposition of AlScN thin films with homogeneous thickness and composition on production size wafers (150-200 mm) and present some preliminary results on the assessment of the structural and piezoelectric properties of the films with Sc content of about 6.5 at.%. The technique is based on the use of pure Sc ingots embedded into the Al targets of the dual-target S-gun magnetron enabling reactive sputtering with high radial thickness and composition homogeneity. Rutherford backscattering spectrometry was carried out to obtain the film composition. The microstructure and morphology were assessed by X-ray diffraction. Density was determined by X-ray grazing angle reflectometry. Electroacoustic properties and dielectric constant were derived from the frequency response of BAW test resonators. 1 μm-thick films showed wurtzite structure with pure c-axis orientation and rocking curves of the (00·2) diffraction peak with FWHM as low as 1.5°. Film properties appear to be uniform across 150-mm wafers. The material electromechanical coupling factor reached 9%, although the sound velocity of longitudinal mode was relatively low (around 8500 m/s).","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"1 1","pages":"117-120"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74448158","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.2015.7138932
P. Bourgeois, T. Imaike, G. Goavec-Mérou, E. Rubiola
We report on the measurement of phase noise of high speed analog to digital converters in a full digital measurement setup and for various development boards. The tested configurations ensures a Nyquist rate higher than 100 MHz suitable for conventional ultralow noise devices. Several analog to digital converters featuring a SNR higher than 140 dB enable the measurement of AM and PM noise with a background noise of -185 dBc (floor) and -160 dBc (flicker, 10 Hz off the carrier) using cross-correlation technique.
{"title":"Noise in high-speed digital-to-analog converters","authors":"P. Bourgeois, T. Imaike, G. Goavec-Mérou, E. Rubiola","doi":"10.1109/FCS.2015.7138932","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138932","url":null,"abstract":"We report on the measurement of phase noise of high speed analog to digital converters in a full digital measurement setup and for various development boards. The tested configurations ensures a Nyquist rate higher than 100 MHz suitable for conventional ultralow noise devices. Several analog to digital converters featuring a SNR higher than 140 dB enable the measurement of AM and PM noise with a background noise of -185 dBc (floor) and -160 dBc (flicker, 10 Hz off the carrier) using cross-correlation technique.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"68 1","pages":"672-675"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75596025","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.2015.7138804
P. Guillemot, G. Cibiel, Yves Richard, J.-M. Tarot, G. Richard
The story probably started somewhere on the planet Mars in the middle of the 90s' when the Sojourner rover demonstrated that it was possible to make great space missions with `low cost' systems. It was the beginning of the `Better / Faster / Cheaper' period. It led space agencies and space industry to develop space equipment using `professional' systems instead of full space qualified ones. In 1995, the CNES, the French Space Agency, decided to develop a family of `low cost' space miniaturized OCXOs. A so called EWOS-0500 micro OCXO, used up to then for distress beacons, was selected for this purpose. The EWOS-0500 was a very small size (DIL 14, 1.5 cm3) and low power (150 mW) OCXO with a short-term stability in the 10-11 range (A-Dev) and a frequency stability of 0.2 ppm in the temperature range [-30 °C; +60°C]. A specific qualification program was set up, to demonstrate the performances and the capability of this OCXO to fulfil space missions. The EWOS-0513 micro OCXO was born. The EWOS-513 was embarked on numerous space missions, mainly in low earth orbit. But some of them were also embarked on the Rosetta mission for a 10 years journey through the solar system up to the 67P/Churyumov-Gerasimenko comet. Once arrived, they contributed to the success of the mission, allowing telecommunication between the orbiter and the lander and being involved in the science program through the CONSERT instrument. This paper redraws the main steps and the main performances of this program that led an oscillator initially intended for distress beacons to contribute to the success of the Rosetta mission.
{"title":"Micro OXCO EWOS-0513: A 20 years space odyssey up to 67P/Churyumov-Gerasimenko","authors":"P. Guillemot, G. Cibiel, Yves Richard, J.-M. Tarot, G. Richard","doi":"10.1109/FCS.2015.7138804","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138804","url":null,"abstract":"The story probably started somewhere on the planet Mars in the middle of the 90s' when the Sojourner rover demonstrated that it was possible to make great space missions with `low cost' systems. It was the beginning of the `Better / Faster / Cheaper' period. It led space agencies and space industry to develop space equipment using `professional' systems instead of full space qualified ones. In 1995, the CNES, the French Space Agency, decided to develop a family of `low cost' space miniaturized OCXOs. A so called EWOS-0500 micro OCXO, used up to then for distress beacons, was selected for this purpose. The EWOS-0500 was a very small size (DIL 14, 1.5 cm3) and low power (150 mW) OCXO with a short-term stability in the 10-11 range (A-Dev) and a frequency stability of 0.2 ppm in the temperature range [-30 °C; +60°C]. A specific qualification program was set up, to demonstrate the performances and the capability of this OCXO to fulfil space missions. The EWOS-0513 micro OCXO was born. The EWOS-513 was embarked on numerous space missions, mainly in low earth orbit. But some of them were also embarked on the Rosetta mission for a 10 years journey through the solar system up to the 67P/Churyumov-Gerasimenko comet. Once arrived, they contributed to the success of the mission, allowing telecommunication between the orbiter and the lander and being involved in the science program through the CONSERT instrument. This paper redraws the main steps and the main performances of this program that led an oscillator initially intended for distress beacons to contribute to the success of the Rosetta mission.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"7 1","pages":"121-124"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78624048","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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