Accurate calculations are performed of atomic trajectories in conventional cesium beam tubes (CBTs) using dispersive, two-wire field magnets and also in a novel configuration using two orthogonal one-dimensional focusing dipoles of the type described by P. Kartaschoff (1969). In the first configuration, it was possible to explain observed differences in atomic velocity distribution in terms of small variations in oven and/or detector offsets. The second configuration yields beam intensities that are significantly higher than the ones obtained with dispersive magnets and/or substantially lower atomic velocities, and thus could improve the frequency stability of compact cesium clocks in the white-noise regime. Present design differs from P. Kartaschoff's prescription in that a one-dimensional focussing dipole, rather than a hexapole or quadrupole magnet, is used as the A magnet in the CBT, making the tube manufacturing simpler.<>
{"title":"Atomic trajectories in compact cesium beam clocks","authors":"B. Jaduszliwer","doi":"10.1109/FREQ.1989.68860","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68860","url":null,"abstract":"Accurate calculations are performed of atomic trajectories in conventional cesium beam tubes (CBTs) using dispersive, two-wire field magnets and also in a novel configuration using two orthogonal one-dimensional focusing dipoles of the type described by P. Kartaschoff (1969). In the first configuration, it was possible to explain observed differences in atomic velocity distribution in terms of small variations in oven and/or detector offsets. The second configuration yields beam intensities that are significantly higher than the ones obtained with dispersive magnets and/or substantially lower atomic velocities, and thus could improve the frequency stability of compact cesium clocks in the white-noise regime. Present design differs from P. Kartaschoff's prescription in that a one-dimensional focussing dipole, rather than a hexapole or quadrupole magnet, is used as the A magnet in the CBT, making the tube manufacturing simpler.<<ETX>>","PeriodicalId":294361,"journal":{"name":"Proceedings of the 43rd Annual Symposium on Frequency Control","volume":"154 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124522248","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}
Various methods of determining electrode mass loading are presented, and measurements of mass loading using several of these techniques are compared. Variations between the values of mass loading obtained by the different techniques are discussed and a model is proposed to explain the differences. A simple first approximation to the effects of lateral boundedness which provides qualitative insights as to the cause of the variations is presented.<>
{"title":"Mass loading measurements of quartz crystal plates","authors":"J. Kosiński, S. Mallikarjun, A. Ballato","doi":"10.1109/FREQ.1989.68891","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68891","url":null,"abstract":"Various methods of determining electrode mass loading are presented, and measurements of mass loading using several of these techniques are compared. Variations between the values of mass loading obtained by the different techniques are discussed and a model is proposed to explain the differences. A simple first approximation to the effects of lateral boundedness which provides qualitative insights as to the cause of the variations is presented.<<ETX>>","PeriodicalId":294361,"journal":{"name":"Proceedings of the 43rd Annual Symposium on Frequency Control","volume":"147 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124707634","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}
The use of thick nonporous Au/Cr electrodes which can lead to a change in the sweeping mechanism is discussed. With these electrodes, a color-center front advances from anode to cathode in quartz that is swept in air at temperatures below the alpha - beta transition. Evidence is presented which indicates that: (1) color centers form beneath nonporous portions of the anode that correlate with the formation of interface Cr-oxides and silicides; (2) clear striae are created along the C-axis where color centers either do not form or are subsequently bleached along cylindrical volumes which correlate with openings in the anode; (3) the clear cylindrical volumes have diameters much larger than the metal openings; (4) a uniformly colored region can form in areas close to but not covered by the anode. Also, a clear band forms between the uniformly colored region and the striated region associated with the anode.<>
{"title":"Update on possible electrode mechanisms in the sweeping of alpha quartz","authors":"J. Gualtieri, L. Calderon, R. Lareau","doi":"10.1109/FREQ.1989.68910","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68910","url":null,"abstract":"The use of thick nonporous Au/Cr electrodes which can lead to a change in the sweeping mechanism is discussed. With these electrodes, a color-center front advances from anode to cathode in quartz that is swept in air at temperatures below the alpha - beta transition. Evidence is presented which indicates that: (1) color centers form beneath nonporous portions of the anode that correlate with the formation of interface Cr-oxides and silicides; (2) clear striae are created along the C-axis where color centers either do not form or are subsequently bleached along cylindrical volumes which correlate with openings in the anode; (3) the clear cylindrical volumes have diameters much larger than the metal openings; (4) a uniformly colored region can form in areas close to but not covered by the anode. Also, a clear band forms between the uniformly colored region and the striated region associated with the anode.<<ETX>>","PeriodicalId":294361,"journal":{"name":"Proceedings of the 43rd Annual Symposium on Frequency Control","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133214858","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}
Measurements are reported of the spectral performance of two types of analog dividers: a parametric divider using varactor diodes, and a regenerative-type divider incorporating a double balanced mixer in the oscillator feedback circuit. Both dividers were configured for divide-by-two operation at VHF. The parametric divider typically requires a moderately high input drive level and operates over relatively narrow bandwidth owing to the nature of the circuit constraints for generation of negative resistance at the output frequency =f/sub in2/. Prototype dividers were constructed utilizing abrupt junction varactor diodes and were designed without the need for the critical tuning or the input and output trap circuits normally used. At the specified 20 dBm drive, 6 dB conversion loss was obtained. Lowest 1/f noise was obtained with the varactor biased to insure nonconduction over the entire cycle of the RF waveform. Unlike the parametric divider, a regenerative-type divider can be operated over a wide range of drive levels and over a much wider bandwidth. The use of the regenerative-type divider appears especially attractive because it provides low 1/f noise and noise floor performance.<>
{"title":"Phase noise performance of analog frequency dividers","authors":"M. Driscoll","doi":"10.1109/FREQ.1989.68888","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68888","url":null,"abstract":"Measurements are reported of the spectral performance of two types of analog dividers: a parametric divider using varactor diodes, and a regenerative-type divider incorporating a double balanced mixer in the oscillator feedback circuit. Both dividers were configured for divide-by-two operation at VHF. The parametric divider typically requires a moderately high input drive level and operates over relatively narrow bandwidth owing to the nature of the circuit constraints for generation of negative resistance at the output frequency =f/sub in2/. Prototype dividers were constructed utilizing abrupt junction varactor diodes and were designed without the need for the critical tuning or the input and output trap circuits normally used. At the specified 20 dBm drive, 6 dB conversion loss was obtained. Lowest 1/f noise was obtained with the varactor biased to insure nonconduction over the entire cycle of the RF waveform. Unlike the parametric divider, a regenerative-type divider can be operated over a wide range of drive levels and over a much wider bandwidth. The use of the regenerative-type divider appears especially attractive because it provides low 1/f noise and noise floor performance.<<ETX>>","PeriodicalId":294361,"journal":{"name":"Proceedings of the 43rd Annual Symposium on Frequency Control","volume":"352 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115163516","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}
The design and performance of surface acoustic wave (SAW) resonator oscillators using techniques for obtaining low phase noise levels are described. These oscillators are very low phase noise engineering prototypes which also meet other vital system requirements, such as temperature stability and vibration sensitivity. A 500-MHz version has a phase noise floor of -177 dBc/Hz and a flicker noise level of -132 dBc/Hz at 1 kHz offset. An L-band (frequency-doubled) version has noise levels of -171 dBc/Hz and -126 dBc/Hz, respectively. Other important performance parameters that are discussed include: temperature dependence of frequency and output power, vibration sensitivity, frequency tuning characteristics, spurious levels, load pulling, voltage pushing and long-term frequency stability.<>
{"title":"Low-noise SAW resonator oscillators","authors":"T. Parker, G. K. Montress","doi":"10.1109/FREQ.1989.68919","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68919","url":null,"abstract":"The design and performance of surface acoustic wave (SAW) resonator oscillators using techniques for obtaining low phase noise levels are described. These oscillators are very low phase noise engineering prototypes which also meet other vital system requirements, such as temperature stability and vibration sensitivity. A 500-MHz version has a phase noise floor of -177 dBc/Hz and a flicker noise level of -132 dBc/Hz at 1 kHz offset. An L-band (frequency-doubled) version has noise levels of -171 dBc/Hz and -126 dBc/Hz, respectively. Other important performance parameters that are discussed include: temperature dependence of frequency and output power, vibration sensitivity, frequency tuning characteristics, spurious levels, load pulling, voltage pushing and long-term frequency stability.<<ETX>>","PeriodicalId":294361,"journal":{"name":"Proceedings of the 43rd Annual Symposium on Frequency Control","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114608104","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}
The evolution of the dielectric resonator filter (DRF) design is discussed and the incorporation of this design into a low-noise dielectric resonator oscillator (DRO) is described. The results of each intermediate step are included along with the final results. The unique properties of the DRF allow it to have a loaded Q of >6500 at 1.538 GHz with an insertion loss of approximately 6 dB while maintaining a vibration sensitivity 2.2*10/sup -8/ (G/sup -1/). The use of high-pressure bonding and the elimination of the metallization at the cavity and substrate interface allows this configuration to work.<>
{"title":"L-band dielectric resonator filters and oscillators with low vibration sensitivity and ultra low noise","authors":"S. Sparagna","doi":"10.1109/FREQ.1989.68842","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68842","url":null,"abstract":"The evolution of the dielectric resonator filter (DRF) design is discussed and the incorporation of this design into a low-noise dielectric resonator oscillator (DRO) is described. The results of each intermediate step are included along with the final results. The unique properties of the DRF allow it to have a loaded Q of >6500 at 1.538 GHz with an insertion loss of approximately 6 dB while maintaining a vibration sensitivity 2.2*10/sup -8/ (G/sup -1/). The use of high-pressure bonding and the elimination of the metallization at the cavity and substrate interface allows this configuration to work.<<ETX>>","PeriodicalId":294361,"journal":{"name":"Proceedings of the 43rd Annual Symposium on Frequency Control","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131202216","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}
The distinction is shown between characterizing a complete oscillator, and characterizing only the quartz resonator by using a passive phase bridge. Advantages and disadvantages of the two approaches are discussed. Then measurements of temperature sensitivities, including quasistatic or dynamic thermal conditions are presented. One important points how to measure the real temperature of the device under test (quartz crystal for instance) rather than the temperature of the probe. Methods for measuring acceleration and pressure sensitivities are presented taking spurious effects of temperature changes into consideration. Various problems are discussed in connection with the measurement of the sensitivity to magnetic fields and electric fields.<>
{"title":"Characterization methods for the sensitivity of quartz oscillators to the environment","authors":"J. Gagnepain","doi":"10.1109/FREQ.1989.68872","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68872","url":null,"abstract":"The distinction is shown between characterizing a complete oscillator, and characterizing only the quartz resonator by using a passive phase bridge. Advantages and disadvantages of the two approaches are discussed. Then measurements of temperature sensitivities, including quasistatic or dynamic thermal conditions are presented. One important points how to measure the real temperature of the device under test (quartz crystal for instance) rather than the temperature of the probe. Methods for measuring acceleration and pressure sensitivities are presented taking spurious effects of temperature changes into consideration. Various problems are discussed in connection with the measurement of the sensitivity to magnetic fields and electric fields.<<ETX>>","PeriodicalId":294361,"journal":{"name":"Proceedings of the 43rd Annual Symposium on Frequency Control","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129584962","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}
A design philosophy for low-cost, high-volume SAW resonators and coupled resonators is presented. In view of the low-cost constraint, only configurations requiring a single level of metallization are considered. To illustrate the design concepts involved, examples are given of alternate resonator topologies and their important performance characteristics are discussed. Design emphasis was on resonators having good out-of-band characteristics. Two novel resonator structures that have been developed with essentially symmetric out-of-band responses are described. Both use only single-level metallization and no grooves. The fundamental difference between the two approaches is that the first structure requires NSPUDT (Natural Single-Phase Unidirectional Transducer) orientations, while the second can be built on conventional crystal orientations.<>
{"title":"Low-cost high-performance resonator and coupled-resonator design: NSPUDT and other innovative structures","authors":"P. Wright","doi":"10.1109/FREQ.1989.68918","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68918","url":null,"abstract":"A design philosophy for low-cost, high-volume SAW resonators and coupled resonators is presented. In view of the low-cost constraint, only configurations requiring a single level of metallization are considered. To illustrate the design concepts involved, examples are given of alternate resonator topologies and their important performance characteristics are discussed. Design emphasis was on resonators having good out-of-band characteristics. Two novel resonator structures that have been developed with essentially symmetric out-of-band responses are described. Both use only single-level metallization and no grooves. The fundamental difference between the two approaches is that the first structure requires NSPUDT (Natural Single-Phase Unidirectional Transducer) orientations, while the second can be built on conventional crystal orientations.<<ETX>>","PeriodicalId":294361,"journal":{"name":"Proceedings of the 43rd Annual Symposium on Frequency Control","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131202013","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}
Synthetic samples in the alpha phase at 550 degrees C and in the beta phase at 650 degrees C were studied with air and vacuum atmosphere and Pt foil electrodes. The electrical current variation was measured both during sweeping and final cooling, giving activation energies in the alpha and beta phase. The samples were characterized by IR measurements at 77 K: a complete disappearance of the OH lines was observed after vacuum sweeping in the alpha phase (550 degrees C-3500 V/cm) or in the beta phase (650 degrees C-1500 V/cm). Considerable modification of the birefringence variations within the incommensurate phase was found. Samples that are heated in the beta phase become twinned; however, a torque can detwin the major part of a AT-cut twinned sample.<>
{"title":"Study of quartz sweeping in alpha and beta phases","authors":"J.P. Balchheimer, G. Dolino","doi":"10.1109/FREQ.1989.68911","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68911","url":null,"abstract":"Synthetic samples in the alpha phase at 550 degrees C and in the beta phase at 650 degrees C were studied with air and vacuum atmosphere and Pt foil electrodes. The electrical current variation was measured both during sweeping and final cooling, giving activation energies in the alpha and beta phase. The samples were characterized by IR measurements at 77 K: a complete disappearance of the OH lines was observed after vacuum sweeping in the alpha phase (550 degrees C-3500 V/cm) or in the beta phase (650 degrees C-1500 V/cm). Considerable modification of the birefringence variations within the incommensurate phase was found. Samples that are heated in the beta phase become twinned; however, a torque can detwin the major part of a AT-cut twinned sample.<<ETX>>","PeriodicalId":294361,"journal":{"name":"Proceedings of the 43rd Annual Symposium on Frequency Control","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117086785","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}
Recent investigations on the magnetic sensitivity of certain on-board quartz crystal oscillators are presented. A part of the study deals with the global magnetic sensitivity of the devices as a function of the magnetic field intensity and direction. Measurements were done on various ovened oscillators used in actual satellites. In addition, in order to determine the origin of the magnetically induced frequency shift, some components were separated from the oscillator and individually submitted to the magnetic field. The work presents the experimental setup, measurement procedures and results obtained at the CNRS laboratory in Besancon. Special attention is paid to the quartz crystal resonator itself. It is shown to have a sensitivity on the order of 10/sup -12//G. An explanation of the resonator's magnetic sensitivity is given, and related verification experiments are presented.<>
{"title":"Influence of magnetic field on quartz crystal oscillators","authors":"R. Brendel, C. El Hassani, M. Brunet, E. Robert","doi":"10.1109/FREQ.1989.68877","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68877","url":null,"abstract":"Recent investigations on the magnetic sensitivity of certain on-board quartz crystal oscillators are presented. A part of the study deals with the global magnetic sensitivity of the devices as a function of the magnetic field intensity and direction. Measurements were done on various ovened oscillators used in actual satellites. In addition, in order to determine the origin of the magnetically induced frequency shift, some components were separated from the oscillator and individually submitted to the magnetic field. The work presents the experimental setup, measurement procedures and results obtained at the CNRS laboratory in Besancon. Special attention is paid to the quartz crystal resonator itself. It is shown to have a sensitivity on the order of 10/sup -12//G. An explanation of the resonator's magnetic sensitivity is given, and related verification experiments are presented.<<ETX>>","PeriodicalId":294361,"journal":{"name":"Proceedings of the 43rd Annual Symposium on Frequency Control","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126424683","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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