1、BRITISH STANDARDBS EN 60027-2:2007Letter symbols to be used in electrical technology Part 2: Telecommunications and electronicsThe European Standard EN 60027-2:2007 has the status of a British StandardICS 01.060; 01.075; 29.020g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g5
2、3g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 60027-2:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 September 2007 BSI 2007ISBN 978 0 580 53414 0N
3、ational forewordThis British Standard is the UK implementation of EN 60027-2:2007. It is identical to IEC 60027-2:2005.The UK participation in its preparation was entrusted to Technical Committee SS/7, General metrology, quantities, units and symbols.A list of organizations represented on this commi
4、ttee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments issued since publica
5、tionAmd. No. Date CommentsEUROPEAN STANDARD EN 60027-2 NORME EUROPENNE EUROPISCHE NORM April 2007 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35,
6、B - 1050 Brussels 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60027-2:2007 E ICS 01.060 Supersedes HD 60027-2:2003English version Letter symbols to be used in electrical technology - Part 2: Telecommunications and electro
7、nics (IEC 60027-2:2005) Symboles littraux utiliser en lectrotechnique - Partie 2: Tlcommunications et lectronique (CEI 60027-2:2005) Formelzeichen fr die Elektrotechnik - Teil 2: Telekommunikation und Elektronik (IEC 60027-2:2005) This European Standard was approved by CENELEC on 2007-04-01. CENELEC
8、 members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on appl
9、ication to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretar
10、iat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Ne
11、therlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Foreword The text of the International Standard IEC 60027-2:2005, prepared by IEC TC 25, Quantities and units, and their letter symbols, was submitted to the Unique Acceptance Procedu
12、re and was approved by CENELEC as EN 60027-2 on 2007-04-01 without any modification. This European Standard supersedes HD 60027-2:2003. EN 60027-2:2007 includes the following significant technical changes with respect to HD 60027-2:2003: it contains a revision of some clauses of HD 245.2 S1:1983 tha
13、t were not technically revised in HD 60027-2:2003; it contains a revision of Clause 8 which is now Clause 10; it contains some new clauses dealing with subjects that were not previously considered; former Clause 10 will be given in another part of EN 60027; former Clause 11 will be revised as EN 600
14、27-6. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2008-04-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2010-04-01 Anne
15、x ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 60027-2:2005 was approved by CENELEC as a European Standard without any modification. _ EN 60027-2:2007 2 CONTENTS 1 Scope.4 2 Normative references .4 3 General concepts .6 3.1 General.6 3.2 Linear networ
16、ks.17 3.2.1 General .17 3.2.2 Two-port linear networks under sinusoidal conditions 17 3.2.3 n-port linear networks under sinusoidal conditions .25 3.3 Line transmission of signals and telephony31 3.3.1 General .31 3.3.2 Line transmission 31 3.3.3 Subscripts for line transmission .32 3.3.4 Telephony
17、.33 3.3.5 Subscripts for telephony 34 3.4 Waveguide propagation.35 3.4.1 Frequency and wavelength in a waveguide35 3.4.2 Characteristic and normalized impedance and admittance in general (unbounded space, waveguide or transmission line) 35 3.4.3 Impedance and admittance at a point in a substance.36
18、3.4.4 Impedance and admittance at a point in vacuum .36 3.4.5 Impedance and admittance of a waveguide .37 3.5 Radiocommunications .38 3.5.1 General .38 3.5.2 General and tropospheric propagation .38 3.5.3 Ionospheric propagation 40 3.5.4 Antennas .41 3.5.5 Radio links 45 3.6 Optical fibre communicat
19、ion 47 3.7 Television .52 3.8 Data processing and data transmission .54 3.8.1 Teletraffic 54 3.8.2 Data processing and digital transmission.55 3.8.3 Prefixes for binary multiples 59 3.9 Information theory .60 3.10 Dependability 63 3.11 Equivalent circuits of piezoelectric crystal units .65 3.12 Semi
20、conductor devices .69 3.13 Electroacoustics 69 Annex ZA (normative) Normative references to international publications with their corresponding European publications72 3 EN 60027-2:2007LETTER SYMBOLS TO BE USED IN ELECTRICAL TECHNOLOGY Part 2: Telecommunications and electronics 1 Scope This part of
21、IEC 60027 is applicable to telecommunications and electronics. It gives names and symbols for quantities and units. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated refe
22、rences, the latest edition of the referenced document (including any amendments) applies. IEC 60027-1:1992, Letter symbols to be used in electrical technology Part 1: General IEC 60027-3:2002, Letter symbols to be used in electrical technology Part 3: Logarithmic and related quantities IEC 60050-101
23、:1998, International Electrotechnical Vocabulary Part 101: Mathematics IEC 60050-131:2002, International Electrotechnical Vocabulary Part 131 Circuit theory IEC 60050-191:1990, International Electrotechnical Vocabulary Part 191: Dependability and quality of service IEC 60050-351:1998, International
24、Electrotechnical Vocabulary Part 351: Automatic control IEC 60050-702:1992, International Electrotechnical Vocabulary Part 702: Oscillations, signals and related devices IEC 60050-704:1993, International Electrotechnical Vocabulary Part 704: Transmission IEC 60050-705:1995, International Electrotech
25、nical Vocabulary Part 705: Radio wave propagation IEC 60050-712:1992, International Electrotechnical Vocabulary Part 712: Antennas IEC 60050-713:1998, International Electrotechnical Vocabulary Part 713: Radiocommuni-cations: transmitters, receivers, networks and operation IEC 60050-715:1996, Telecom
26、munication networks, teletraffic and operation IEC 60050-721:1991, International Electrotechnical Vocabulary Part 721: Telegraphy, facsimile and data communication IEC 60050-722:1992, International Electrotechnical Vocabulary Part 722: Telephony IEC 60050-723:1997, International Electrotechnical Voc
27、abulary Part 723: Broadcasting: sound, television, data 4 EN 60027-2:2007IEC 60050-725:1994, International Electrotechnical Vocabulary Part 725: Space radio-communications IEC 60050-726:1982, International Electrotechnical Vocabulary Part 726: Transmission lines and waveguides IEC 60050-731:1991, In
28、ternational Electrotechnical Vocabulary Part 731: Optical fibre communication IEC 60122-1:2002, Quartz crystal units of assessed quality Part 1: Generic specification IEC 60375:2003, Conventions concerning electric and magnetic circuits IEC 60747(all parts), Semiconductor devices Discrete devices IE
29、C 60747-1:1983, Semiconductor devices Discrete devices Part 1: General IEC 60748 (all parts), Semiconductor devices Integrated circuits IEC 60748-1:2002, Semiconductor devices Integrated circuits Part 1: General IEC 61703:2001, Mathematical expressions for reliability, availability, maintainability
30、and maintenance support terms IEC 61931:1998, Fibre optic Terminology ISO/IEC 2382-16:1996, Information technology Vocabulary Part 16: Information theory ISO 31-0:1992, Reference materials Contents of certificates and labels ISO 31-11:1992, Quantities and units Part 11: Mathematical signs and symbol
31、s for use in the physical sciences and technology NOTE 1 In this part of IEC 60027, complex quantities are denoted by underlining their symbols. However, this does not constitute a compulsory rule in applications (see 1.6 in IEC 60027-1). NOTE 2 The heading in the tables “Unit, coherent with the SI“
32、 covers SI units and other units coherent with the SI, such as bar and neper. 5 EN 60027-2:20073 General concepts 3.1 General For logarithmic quantities defined as a logarithm of the ratio of two power or field quantities, respectively, the neper, Np, is coherent with the SI and is a special name fo
33、r the unit one. In practice, however, the submultiple decibel, dB, of the bel, B, is generally used. The bel is not explicitly mentioned in the table. See IEC 60027-3. Quantities Units Item number Entry number in IEV Name of quantity Chief symbol Reserve symbol Remarks Unit, coherent with the SI Oth
34、er units Remarks Name Symbol Name Symbol 101 101-12-02 702-04-01 351-12-16 signal (generic term) S , s The value of a signal is proportional to a physical quantity considered as representing information, with an arbitrary scale. In this document, 1S and 2S are used for input and output signals respe
35、ctively; see IEC 60027-1:1992 for suitable subscripts. In cases where the type of signal quantity is known, for example, electric current, voltage, pressure, etc., use the appropriate symbol. With respect to capital and lower-case letters, see IEC 60027-1:1992, 2.1. The unit depends on the kind of q
36、uantity constituting the signal (electric current, voltage, pressure, etc.). 102 signal power sP sigP “s“ (lower case, upright) is used as subscript for “signal“. In signal theory, the term “instantaneous power“ is by convention used for the square of the instantaneous value of a signal. This square
37、 is proportional to a physical power if the signal is a field quantity (see IEV 101-14-71, Note 1). watt W In a physical system, a signal power is always a physical power. 103 signal level L sigs, LL reflogSSL = where S and refS are two signals of the same kind, refS being a reference In practice, a
38、 base for the logarithm has to be specified. 103.1 702-07-04 absolute power level; power level PL dB01Np21refreflglnPPPPLP= where P is a power and refP is a reference powerneper Np decibel dB 6EN 60027-2:2007Quantities Units Item number Entry number in IEV Name of quantity Chief symbol Reserve symbo
39、l Remarks Unit, coherent with the SI Other units Remarks Name Symbol Name Symbol 103.2 702-07-06 absolute voltage level; voltage level; absolute tension level; tension level UL dB02NprefreflglnUUUULU= where U is a voltage and refU is a reference voltage neper Np decibel dB 103.3 702-07-05 relative p
40、ower level rL 0,r, PxPxLLL = x refers to the measuring point and 0 to the reference point neper Np decibel dB 103.4 101-14-71 702-04-50 power spectral density (for a signal or noise) )( fw 0N is used for the power spectral density of a white noise =0d)( ffwP where f is frequency. In signal theory, t
41、he term “instantaneous power“ is by convention used for the square of the instantaneous value of a signal or noise. This square is proportional to a physical power if the signal or the noise is a field quantity (see IEV 101-14-71, Note 1). watt per hertz W/Hz In a physical system, the power spectral
42、 density is always a physical power spectral density. 104 101-14-63 702-08-03 noise (generic term) N , n nn, sS Concerning upper-case and lower-case letters, see IEC 60027-1:1992, 2.1. “n“ (lower case, upright) is used as subscript for “noise“. The value of a noise is proportional to a physical quan
43、tity apparently not conveying information, with an arbitrary scale. In cases where the type of noise quantity is known, use the appropriate symbol (for example, I, i for electric current) with n as subscript. The unit depends on the kind of quantity constituting the noise (electric current, voltage,
44、 pressure, etc.). 105.1 702-08-51 equivalent noise voltage; equivalent noise tension nU Applies to a one-port network. volt V 7EN 60027-2:2007Quantities Units Item number Entry number in IEV Name of quantity Chief symbol Reserve symbol Remarks Unit, coherent with the SI Other units Remarks Name Symb
45、ol Name Symbol 105.2 702-08-52 equivalent noise resistance; noise resistance neq, RRApplies to a one-port network. fkTUR=ref2neq4where k is the Boltzmann constant, refT is a reference temperature and f is the frequency bandwidth considered. ohm 106 702-08-54 spot noise temperature T(f) Applies to a
46、one-port network. f is frequency kelvin K 106.1 702-08-55 mean noise temperature T Applies to a one-port network. kelvin K 107 702-08-56 equivalent spot noise temperature )(eqfT Applies to a two-port network. f is frequency kelvin K 107.1 702-08-58 mean equivalent noise temperature; mean noise tempe
47、rature eqT Applies to a two-port network. kelvin K 107.2 702-08-57 spot noise factor )( fF Applies to a two-port network. The noise factor is the ratio of the exchangeable power spectral density of output noise to the power spectral density which would be present at the output if the only source of
48、noise were input thermal noise at a reference temperature refT : refeq)(1)(TfTfF += where f is frequency. one 1 8EN 60027-2:2007Quantities Units Item number Entry number in IEV Name of quantity Chief symbol Reserve symbol Remarks Unit, coherent with the SI Other units Remarks Name Symbol Name Symbol
49、107.3 702-08-57 (Note 2) spot noise factor )(nfF () () ()dB10Np21lglnnfFfFfF = where f is frequency. In English, the term “noise factor” is generally used for the arithmetic expression and term “noise figure” is used for the logarithmic expression. neper Np decibel dB 107.4 702-08-59 mean noise factor; noise factor F Applies to a two-port network. refeq1TTF += where refT is a reference temperature. one 1 107.5 702-08-59 (Note 2) mean noise fi
