Based on Mindlin's first-order equations of plated crystal plates, a set of six coupled equations is derived in which the effect of the mass of the electrodes, the extensional elastic stiffness of the electrodes, and the thermal expansions of the plate and electrodes are taken into account. The principle of virtual displacements corresponding to these equations is obtained. Strains and displacement gradients in an electroded crystal disk subject to a steady acceleration are obtained from the finite-element solutions of the derived equations. By inserting these strains and displacement gradients in the frequency equation of the fundamental thickness vibrations of the disk and solving the frequency equation by a perturbation method, acceleration sensitivities of crystal resonators with various electrode arrangements are obtained. It is found that for small plate backs, say R>
{"title":"Effect of electrodes on the acceleration sensitivity of crystal resonators","authors":"Pcy Lee, X. Guo","doi":"10.1109/FREQ.1989.68898","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68898","url":null,"abstract":"Based on Mindlin's first-order equations of plated crystal plates, a set of six coupled equations is derived in which the effect of the mass of the electrodes, the extensional elastic stiffness of the electrodes, and the thermal expansions of the plate and electrodes are taken into account. The principle of virtual displacements corresponding to these equations is obtained. Strains and displacement gradients in an electroded crystal disk subject to a steady acceleration are obtained from the finite-element solutions of the derived equations. By inserting these strains and displacement gradients in the frequency equation of the fundamental thickness vibrations of the disk and solving the frequency equation by a perturbation method, acceleration sensitivities of crystal resonators with various electrode arrangements are obtained. It is found that for small plate backs, say R<or=0.5%, the percent increase of acceleration sensitivity of an electroded plate as compared with that of an unelectroded plate is essentially proportional to the ratio of the total mass of the attached electrodes to the total mass of the plate.<<ETX>>","PeriodicalId":294361,"journal":{"name":"Proceedings of the 43rd Annual Symposium on Frequency Control","volume":"20 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":"132211626","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 authors establish calculational procedures implemented in a desk top computer program which provide adequate solutions for most problems of interest in reasonable computation times. It uses variational calculus to approximate the displacements in the quartz crystal. Body forces are included to represent acceleration. The mounting structures are included as point boundary conditions represented by spring matrices, relating deflections and rotations to the forces and moments from the mount reactions.<>
{"title":"Variational method for modeling static and dynamic stresses in a resonator disc with mounts","authors":"E. P. Eernisse, L. Clayton, M.H. Watts","doi":"10.1109/FREQ.1989.68893","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68893","url":null,"abstract":"The authors establish calculational procedures implemented in a desk top computer program which provide adequate solutions for most problems of interest in reasonable computation times. It uses variational calculus to approximate the displacements in the quartz crystal. Body forces are included to represent acceleration. The mounting structures are included as point boundary conditions represented by spring matrices, relating deflections and rotations to the forces and moments from the mount reactions.<<ETX>>","PeriodicalId":294361,"journal":{"name":"Proceedings of the 43rd Annual Symposium on Frequency Control","volume":"267 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":"133696752","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}
MIFTTI is a modular time and frequency subsystem that includes built-in intelligence to improve its performance. Modularity is used to achieve maximum configuration flexibility. This work describes the continuing research on the MIFTTI subsystem. The first year of this 30-month program has concentrated on defining the architecture and packaging concepts of the MIFTTI subsystem, design of the basic crystal oscillator and rubidium frequency references, and development of the basic control software. The results are encouraging, and show the potential for significant improvements in the capabilities of military time and frequency subsystems by the incorporation of these concepts.<>
{"title":"The Modular Intelligent Frequency, Time and Time Interval (MIFTTI) subsystem program","authors":"K. Lyon, W. Riley, J.R. Vaccaro","doi":"10.1109/FREQ.1989.68869","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68869","url":null,"abstract":"MIFTTI is a modular time and frequency subsystem that includes built-in intelligence to improve its performance. Modularity is used to achieve maximum configuration flexibility. This work describes the continuing research on the MIFTTI subsystem. The first year of this 30-month program has concentrated on defining the architecture and packaging concepts of the MIFTTI subsystem, design of the basic crystal oscillator and rubidium frequency references, and development of the basic control software. The results are encouraging, and show the potential for significant improvements in the capabilities of military time and frequency subsystems by the incorporation of these concepts.<<ETX>>","PeriodicalId":294361,"journal":{"name":"Proceedings of the 43rd Annual Symposium on Frequency Control","volume":"229 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":"130925230","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 transimpedance oscillator is developed in steps beginning with the bridge oscillator, through transportation of bridge elements, frequency compensation of the resonator arm, and then mechanization of the transimpedance configuration. The analytical basis for performance improvement is shown along with the results of simulations of modeled oscillator circuits and actual circuit tests. In conclusion a means to compensate for the effect of crystal shunt or clamp capacitance variation is suggested.<>
{"title":"Transimpedance crystal oscillator","authors":"L. Ferriss","doi":"10.1109/FREQ.1989.68857","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68857","url":null,"abstract":"The transimpedance oscillator is developed in steps beginning with the bridge oscillator, through transportation of bridge elements, frequency compensation of the resonator arm, and then mechanization of the transimpedance configuration. The analytical basis for performance improvement is shown along with the results of simulations of modeled oscillator circuits and actual circuit tests. In conclusion a means to compensate for the effect of crystal shunt or clamp capacitance variation is suggested.<<ETX>>","PeriodicalId":294361,"journal":{"name":"Proceedings of the 43rd Annual Symposium on Frequency Control","volume":"4 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":"131847043","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}
Improvements in the design and realization of hardened oscillators are proposed to make the piezoelectric equipment insensitive to mechanical or acoustic disturbances. Following extensive experimentation, the following conclusions were reached: the improvement of g sensitivity is a long and expensive process; for a given industrial state of the art, it is preferable to preserve the phase noise characteristics during vibrations by using mechanical absorber structures such as a filter; in order to obtain the same results without absorbers, g sensitivity of some 1.10/sup -12//g would be necessary. However, very close to the carrier frequency, the phase noise during vibrations depends directly on the g sensitivity of the resonator, for either quartz or lithium tantalate.<>
{"title":"Mechanical and acoustic effects in low phase noise piezoelectric oscillators","authors":"P. Renoult, E. Girardet, L. Bidart","doi":"10.1109/FREQ.1989.68902","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68902","url":null,"abstract":"Improvements in the design and realization of hardened oscillators are proposed to make the piezoelectric equipment insensitive to mechanical or acoustic disturbances. Following extensive experimentation, the following conclusions were reached: the improvement of g sensitivity is a long and expensive process; for a given industrial state of the art, it is preferable to preserve the phase noise characteristics during vibrations by using mechanical absorber structures such as a filter; in order to obtain the same results without absorbers, g sensitivity of some 1.10/sup -12//g would be necessary. However, very close to the carrier frequency, the phase noise during vibrations depends directly on the g sensitivity of the resonator, for either quartz or lithium tantalate.<<ETX>>","PeriodicalId":294361,"journal":{"name":"Proceedings of the 43rd Annual Symposium on Frequency Control","volume":"184 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":"114129189","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 biases and the variances are theoretically and experimentally investigated of fast Fourier transform (FFT) spectral estimates with different windows (data tapers) when used to analyze power-law noise types f/sup 0/, f/sup -2/, f/sup -3/ and f/sup -4/. The experimental techniques introduced here permit one to analyze the performance of virtually any window for any power-law noise. This makes it possible to determine the level of a particular noise type to a specified statistical accuracy for a particular window.<>
{"title":"Biases and variances of several FFT spectral estimators as a function of noise type and number of samples","authors":"F. Walls, D. Percival, W. R. Irelan","doi":"10.1109/FREQ.1989.68887","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68887","url":null,"abstract":"The biases and the variances are theoretically and experimentally investigated of fast Fourier transform (FFT) spectral estimates with different windows (data tapers) when used to analyze power-law noise types f/sup 0/, f/sup -2/, f/sup -3/ and f/sup -4/. The experimental techniques introduced here permit one to analyze the performance of virtually any window for any power-law noise. This makes it possible to determine the level of a particular noise type to a specified statistical accuracy for a particular window.<<ETX>>","PeriodicalId":294361,"journal":{"name":"Proceedings of the 43rd Annual Symposium on Frequency Control","volume":"253 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":"116072586","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}
In some crystals, various types of defects are observed which can limit the performances of piezoelectric devices. Two distinct modes of water incorporation have been recognized, namely molecular water (tiny fluid inclusions with diameters down to 30 AA) and isolated point defects like the so-called 4H/sub Si/ defects. The equilibrium concentration of this latter type of defects is extremely low at the usual T and P conditions of growth, but a supersaturation can occur for relatively large growth rates. The equilibrium concentration was determined as a function of T and P, and the diffusivity coefficient of the corresponding water species as a function of temperature was tentatively estimated.<>
{"title":"Growth defects in cultured quartz: a microscopic investigation","authors":"P. Cordier, J. C. Doukhan, X. Buisson, O. Bignon","doi":"10.1109/FREQ.1989.68904","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68904","url":null,"abstract":"In some crystals, various types of defects are observed which can limit the performances of piezoelectric devices. Two distinct modes of water incorporation have been recognized, namely molecular water (tiny fluid inclusions with diameters down to 30 AA) and isolated point defects like the so-called 4H/sub Si/ defects. The equilibrium concentration of this latter type of defects is extremely low at the usual T and P conditions of growth, but a supersaturation can occur for relatively large growth rates. The equilibrium concentration was determined as a function of T and P, and the diffusivity coefficient of the corresponding water species as a function of temperature was tentatively estimated.<<ETX>>","PeriodicalId":294361,"journal":{"name":"Proceedings of the 43rd Annual Symposium on Frequency Control","volume":"53 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":"123521384","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 system described uses microcomputer-controlled compensation wherein the correction is implemented by adding a computed offset frequency to the output of a stable oscillator. Temperature sensing is done by the use of a dual-mode oscillator system using two C-modes of an SC-cut crystal, which are combined to produce a temperature-sensitive difference frequency. System accuracies of +or-20 p.p.b. have been achieved over a temperature range of -55 degrees C to +85 degrees C.<>
{"title":"A microcomputer-compensated crystal oscillator using a dual-mode resonator","authors":"A. Benjaminson, S. C. Stallings","doi":"10.1109/FREQ.1989.68854","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68854","url":null,"abstract":"The system described uses microcomputer-controlled compensation wherein the correction is implemented by adding a computed offset frequency to the output of a stable oscillator. Temperature sensing is done by the use of a dual-mode oscillator system using two C-modes of an SC-cut crystal, which are combined to produce a temperature-sensitive difference frequency. System accuracies of +or-20 p.p.b. have been achieved over a temperature range of -55 degrees C to +85 degrees C.<<ETX>>","PeriodicalId":294361,"journal":{"name":"Proceedings of the 43rd Annual Symposium on Frequency Control","volume":"9 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":"132560908","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}
An investigation and research is reported into the radiation environment of a geostationary satellite and the radiation resistance of quartz resonators to be installed in artificial satellites. The total absorbed dose of a synchronous satellite in a geostationary orbit reaches about 1*10/sup 4/ Gy in ten years. For example, the rate of change of the frequency of a quartz resonator manufactured from an unswept crystal with a Q-value of about 2.8 million was about 0.2*10/sup -6/ at a total absorbed dose of 1*10/sup 5/.<>
{"title":"Frequency drift for quartz resonator irradiated by CO gamma ray","authors":"S. Obara, M. Koyama, A. Chiba, H. Fukuda, H. Ohba","doi":"10.1109/FREQ.1989.68912","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68912","url":null,"abstract":"An investigation and research is reported into the radiation environment of a geostationary satellite and the radiation resistance of quartz resonators to be installed in artificial satellites. The total absorbed dose of a synchronous satellite in a geostationary orbit reaches about 1*10/sup 4/ Gy in ten years. For example, the rate of change of the frequency of a quartz resonator manufactured from an unswept crystal with a Q-value of about 2.8 million was about 0.2*10/sup -6/ at a total absorbed dose of 1*10/sup 5/.<<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":"129658503","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 are reported of an oscillator incorporating 16 PIN diode switch-selectable, fifth-overtone crystals operating in the 100-MHz range. A lumped-element, quarter-wavelength line provides a means for absorption of the printed wiring board track connections and switch parasitic reactances for the 15 switched-off crystals. PIN (rather than Schottky) diodes were utilized because they have lower off-state capacitance and PIN diode use has no measurable degrading influence on oscillator signal phase noise performance. Oscillator flicker of frequency noise is characterized by Sy(100 Hz)=3*10/sup -25/ and is due to short-term instability in the resonators themselves. The pulse noise floor level is -169 dB/Hz. Using modest levels of excess gain, interchannel frequency switching time is on the order of 2 ms, compared to 9-ms turn-on time.<>
{"title":"A low-noise, multiple-frequency oscillator utilizing large numbers of electronic switch-selectable crystals","authors":"M. Driscoll, N. Matthews","doi":"10.1109/FREQ.1989.68838","DOIUrl":"https://doi.org/10.1109/FREQ.1989.68838","url":null,"abstract":"The design and performance are reported of an oscillator incorporating 16 PIN diode switch-selectable, fifth-overtone crystals operating in the 100-MHz range. A lumped-element, quarter-wavelength line provides a means for absorption of the printed wiring board track connections and switch parasitic reactances for the 15 switched-off crystals. PIN (rather than Schottky) diodes were utilized because they have lower off-state capacitance and PIN diode use has no measurable degrading influence on oscillator signal phase noise performance. Oscillator flicker of frequency noise is characterized by Sy(100 Hz)=3*10/sup -25/ and is due to short-term instability in the resonators themselves. The pulse noise floor level is -169 dB/Hz. Using modest levels of excess gain, interchannel frequency switching time is on the order of 2 ms, compared to 9-ms turn-on time.<<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":"120962616","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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