1、IEEE Std 1139-2008(Revision ofIEEE Std 1139-1999)IEEE Standard Definitions of Physical Quantities for Fundamental Frequency and TimeMetrologyRandom InstabilitiesIEEE3 Park Avenue New York, NY 10016-5997, USA27 February 2009IEEE Standards Coordinating Committee 27Sponsored by theIEEE Standards Coordi
2、nating Committee 27 on Time and Frequency1139TMIEEE Std 1139-2008 (Revision of IEEE Std 1139-1999) IEEE Standard Definitions of Physical Quantities for Fundamental Frequency and Time MetrologyRandom Instabilities Sponsor IEEE Standards Coordinating Committee 27 on Time and Frequency Approved 26 Sept
3、ember 2008 IEEE-SA Standards Board Abstract: Methods of describing random instabilities of importance to frequency and time metrology are covered. Quantities covered include frequency, amplitude, and phase instabilities; spectral densities of frequency, amplitude, and phase fluctuations; and time-do
4、main deviations of frequency fluctuations. In addition, recommendations are made for the reporting of measurements of frequency, amplitude, and phase instabilities, especially in regard to the recording of experimental parameters, experimental conditions, and calculation techniques. Keywords: AM noi
5、se, amplitude instability, FM noise, frequency domain, frequency instability, frequency metrology, frequency modulation, noise, phase instability, phase modulation, phase noise, PM noise, time domain, time metrology The Institute of Electrical and Electronics Engineers, Inc. 3 Park Avenue, New York,
6、 NY 10016-5997, USA Copyright 2009 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Published 27 February 2009. Printed in the United States of America. IEEE is a registered trademark in the U.S. Patent +1 978 750 8400. Permission to photocopy portions of any indiv
7、idual standard for educational classroom use can also be obtained through the Copyright Clearance Center. iv Copyright 2009 IEEE. All rights reserved. Introduction This introduction is not part of IEEE Std 1139-2008, IEEE Standard Definitions of Physical Quantities for Fundamental Frequency and Time
8、 MetrologyRandom Instabilities. Techniques to characterize and to measure the frequency, phase, and amplitude instabilities in frequency and time devices and in received radio signals are of fundamental importance to all manufacturers and users of frequency and time technology. In 1964, Standards Co
9、ordinating Committee 14 and, in 1966, the Technical Committee on Frequency and Time were formed to prepare an IEEE standard on frequency stability. In 1969, these committees completed a document proposing definitions for measures of frequency and phase stabilities (Barnes B14).aIn 1988, an updated I
10、EEE standard on frequency stability was published as IEEE Std 1139-1988, IEEE Standard Definitions of Physical Quantities for Fundamental Frequency and Time Metrology. Later on a revision of this standard was published as IEEE Std 1139-1999, IEEE Standard Definitions of Physical Quantities for Funda
11、mental Frequency and Time MetrologyRandom Instabilities. The recommended measures of instabilities in frequency generators have gained acceptance among frequency and time users throughout the world. This standard is a revision of IEEE Std 1139-1999, which had been prepared by a previous Standards Co
12、ordinating Committee 27, consisting of John R. Vig, Chair; Eva S. Ferre-Pikal, Vice Chair; James C. Camparo, Leonard S. Cutler, Lute Maleki, William J. Riley, Samuel R. Stein, Claudine Thomas, Fred L. Walls, and Joseph D. White. Some clauses of the 1999 standard remain unchanged. Most of the major m
13、anufacturers now specify instability characteristics of their standards in terms of the recommended measures. This standard thus defines and formalizes the general practice. Notice to users Laws and regulations Users of these documents should consult all applicable laws and regulations. Compliance w
14、ith the provisions of this standard does not imply compliance to any applicable regulatory requirements. Implementers of the standard are responsible for observing or referring to the applicable regulatory requirements. IEEE does not, by the publication of its standards, intend to urge action that i
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16、ate self-regulation, standardization, and the promotion of engineering practices and methods. By making this document available for use and adoption by public authorities and private users, the IEEE does not waive any rights in copyright to this document. aThe numbers in brackets correspond to those
17、 of the bibliography in Annex F. v Copyright 2009 IEEE. All rights reserved. Updating of IEEE documents Users of IEEE standards should be aware that these documents may be superseded at any time by the issuance of new editions or may be amended from time to time through the issuance of amendments, c
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19、ssuance of amendments, corrigenda, or errata, visit the IEEE Standards Association Web site at http:/ieeexplore.ieee.org/xpl/standards.jsp, or contact the IEEE at the address listed previously. For more information about the IEEE Standards Association or the IEEE standards development process, visit
20、 the IEEE-SA Web site at http:/standards.ieee.org. Errata Errata, if any, for this and all other standards can be accessed at the following URL: http:/standards.ieee.org/reading/ieee/updates/errata/index.html. Users are encouraged to check this URL for errata periodically. Interpretations Current in
21、terpretations can be accessed at the following URL: http:/standards.ieee.org/reading/ieee/interp/ index.html. Patents Attention is called to the possibility that implementation of this standard may require use of subject matter covered by patent rights. By publication of this standard, no position i
22、s taken with respect to the existence or validity of any patent rights in connection therewith. The IEEE is not responsible for identifying Essential Patent Claims for which a license may be required, for conducting inquiries into the legal validity or scope of Patents Claims or determining whether
23、any licensing terms or conditions provided in connection with submission of a Letter of Assurance, if any, or in any licensing agreements are reasonable or non-discriminatory. Users of this standard are expressly advised that determination of the validity of any patent rights, and the risk of infrin
24、gement of such rights, is entirely their own responsibility. Further information may be obtained from the IEEE Standards Association. vi Copyright 2009 IEEE. All rights reserved. Participants At the time this standard was submitted to the IEEE-SA Standards Board for approval, the 1139 Working Group
25、had the following membership: Eva S. Ferre-Pikal, Chair John R. Vig, Vice Chair James C. Camparo Christopher R. Ekstrom Charles A. Greenhall Lute Maleki Victor Reinhardt William J. Riley Fred L. Walls Joseph D. WhiteThe following members of the individual balloting committee voted on this standard.
26、Balloters may have voted for approval, disapproval, or abstention. William J. Ackerman Ali Al Awazi Martin J. Bishop Keith Chow Kevin Coggins Eva S. Ferre-Pikal Robert Graham Randall Groves Werner Hoelzl Piotr Karocki G. Luri Bruce Muschlitz Michael S. Newman Charles Ngethe Ulrich Pohl Michael Rober
27、ts Bartien Sayogo James E. Smith Walter Struppler John WillisWhen the IEEE-SA Standards Board approved this standard on 26 September 2008, it had the following membership: Robert M. Grow, Chair Thomas Prevost, Vice Chair Steve M. Mills, Past Chair Judith Gorman, Secretary Victor Berman Richard DeBla
28、sio Andy Drozd Mark Epstein Alexander Gelman William Goldbach Arnie Greenspan Ken Hanus Jim Hughes Richard Hulett Young Kyun Kim Joseph L. Koepfinger* John Kulick David J. Law Glenn Parsons Ron Petersen Chuck Powers Thomas Prevost Narayanan Ramachandran Jon Walter Rosdahl Anne-Marie Sahazizian Malco
29、lm Thaden Howard Wolfman Don Wright *Member Emeritus Also included are the following nonvoting IEEE-SA Standards Board liaisons: Satish K. Aggarwal, NRC Representative Michael Janezic, NIST Representative Lorraine Patsco IEEE Standards Program Manager, Document Development Soo H. Kim IEEE Standards
30、Program Manager, Technical Program Development vii Copyright 2009 IEEE. All rights reserved. Contents 1. Scope 1 2. Definitions 2 3. Standards for characterizing or reporting measurements of frequency, amplitude, and phase instabilities. 2 3.1 Nonrandom phenomena should be recognized 3 3.2 Relevant
31、measurement or specification parameters should be given. 3 Annex A (informative) Measures of frequency, amplitude, and phase instabilities. 4 Annex B (informative) Power-laws and conversion between frequency and time domain 14 Annex C (informative) Examples of computation of deviations 18 Annex D (i
32、nformative) Other variances deviations that have been used to describe frequency instabilities in the time domain 24 Annex E (informative) Confidence limits of measurements 26 Annex F (informative) Bibliography 30 1 Copyright 2009 IEEE. All rights reserved. IEEE Standard Definitions of Physical Quan
33、tities for Fundamental Frequency and Time MetrologyRandom Instabilities IMPORTANT NOTICE: This standard is not intended to ensure safety, security, health, or environmental protection in all circumstances. Implementers of the standard are responsible for determining appropriate safety, security, env
34、ironmental, and health practices or regulatory requirements. This IEEE document is made available for use subject to important notices and legal disclaimers. These notices and disclaimers appear in all publications containing this document and may be found under the heading “Important Notice” or “Im
35、portant Notices and Disclaimers Concerning IEEE Documents.” They can also be obtained on request from IEEE or viewed at http:/standards.ieee.org/IPR/ disclaimers.html. 1. Scope This standard covers the fundamental metrology for describing random instabilities of importance to frequency and time metr
36、ology. Quantities covered include frequency, amplitude, and phase instabilities; spectral densities of frequency, amplitude, and phase fluctuations; and time-domain deviations of frequency fluctuations. In addition, recommendations are made for the reporting of measurements of frequency, amplitude,
37、and phase instabilities, especially in regard to the recording of experimental parameters, experimental conditions, and calculation techniques. The annexes cover basic concepts and definitions, time prediction, and confidence limits when estimating deviations and spectral densities from a finite dat
38、a set. The annexes also cover translation between the frequency domain and time domain instability measures, examples on how to calculate the time-domain measures of frequency fluctuations, and an extensive bibliography of the relevant literature. Systematic instabilities, such as environmental effe
39、cts and aging, are discussed in IEEE Std 1193-2003 B54.11The numbers in brackets correspond to those of the bibliography in Annex F. IEEE Std1139-2008 IEEE Standard Definitions of Physical Quantities for Fundamental Frequency and Time Metrology Random Instabilities 2 Copyright 2009 IEEE. All rights
40、reserved. 2. Definitions For the purposes of this standard, the following terms and definitions apply. The Authoritative Dictionary of IEEE Standards Terms B51 should be referenced for terms not defined in this clause. If ambiguities are created between the narrative definition given here and the ma
41、thematical equation given in the text, the equation has priority. 2.1 amplitude spectrum Sa(f): One-sided spectral density of the normalized amplitude fluctuations, as defined in normalized amplitude fluctuations a(t). 2.2 bias: The difference between the expected value of an estimator of a statisti
42、c and its correct value. 2.3 confidence interval: An interval of uncertainty associated with an estimate of an instability measure from a finite number of measurements. The endpoints of a confidence interval are called confidence limits. 2.4 frequency spectrum Sy(f): One-sided spectral density of th
43、e normalized frequency fluctuations, as defined in normalized frequency fluctuations y(t). 2.5 normalized amplitude fluctuations a(t): Instantaneous normalized amplitude departure from a nominal amplitude. 2.6 normalized frequency fluctuations y(t): Instantaneous, normalized frequency departure from
44、 a nominal frequency. 2.7 phase fluctuations (t): Instantaneous phase departure from a nominal phase. 2.8 phase noise L(f): One-half of the phase spectrum S(f), as defined in phase spectrum S(f). 2.9 phase spectrum S(f): One-sided spectral density of the phase fluctuations. 2.10 time fluctuations x(
45、t): Instantaneous time departure from a nominal time. 2.11 time interval error (TIE): The time difference between a real clock and an ideal uniform time scale following a time period t after perfect synchronization. 2.12 time spectrum Sx(f): One-sided spectral density of the time fluctuations. 2.13
46、two-sample deviation y(): Also called the Allan deviation; the square root of the two sample variance, as defined in two-sample variance y2(). 2.14 two-sample variance y2(): Also called the Allan variance; one-half the time average of the square of the difference between the averages of normalized f
47、requency fluctuations over two adjacent time intervals of length , with no dead time between the two averaging intervals. 3. Standards for characterizing or reporting measurements of frequency, amplitude, and phase instabilities The standard measure for characterizing frequency and phase instabiliti
48、es in the frequency domain is L(f), (pronounced “script-ell of f”), defined as one half of the one-sided spectral density of phase fluctuations: )(21)( fSf=L IEEE Std1139-2008 IEEE Standard Definitions of Physical Quantities for Fundamental Frequency and Time Metrology Random Instabilities 3 Copyrig
49、ht 2009 IEEE. All rights reserved. When expressed in decibels, the units of L(f) are dBc/Hz (dB below the carrier in a 1 Hz bandwidth). A device shall be characterized by a plot of L(f) versus Fourier frequency f. In some applications, providing L(f) versus discrete values of Fourier frequency is sufficient. (See Annex A and Annex B for further discussion). The standard measure for characterizing amplitude instability in the frequency domain is one half of the one-sided spectral density of the normalized amplitude fluctuations, )(21fSa. When e
