Letter symbols to be used in electrical technology - Part 2: Telecommunications and electronics

Defines rules for the use and writing of letter symbols for telecommunications and electronics.

Formelzeichen für die Elektrotechnik - Teil 2: Telekommunikation und Elektronik

Symboles littéraux à utiliser en électrotechnique - Partie 2: Télécommunications et électronique

Définit les règles pour l'utilisation des symboles littéraux dans le domaine des télécommunications et l'électronique.

Črkovni simboli za uporabo v elektrotehnologiji - 2. del: Telekomunikacije in elektronika (IEC 60027-2:2005)

General Information

Status
Withdrawn
Publication Date
24-Apr-2007
Current Stage
6060 - Document made available
Start Date
25-Apr-2007
Completion Date
25-Apr-2007

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Standards Content (sample)

SLOVENSKI STANDARD
SIST EN 60027-2:2008
01-januar-2008
1DGRPHãþD
SIST HD 60027-2:2004
ýUNRYQLVLPEROL]DXSRUDERYHOHNWURWHKQRORJLMLGHO7HOHNRPXQLNDFLMHLQ
HOHNWURQLND ,(&

Letter symbols to be used in electrical technology -- Part 2: Telecommunications and

electronics
Formelzeichen für die Elektrotechnik - Teil 2: Telekommunikation und Elektronik

Symboles littéraux à utiliser en électrotechnique -- Partie 2: Télécommunications et

électronique
Ta slovenski standard je istoveten z: EN 60027-2:2007
ICS:
01.075 Simboli za znake Character symbols
31.020 Elektronske komponente na Electronic components in
splošno general
33.020 Telekomunikacije na splošno Telecommunications in
general
SIST EN 60027-2:2008 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN 60027-2:2008
---------------------- Page: 2 ----------------------
SIST EN 60027-2:2008
EUROPEAN STANDARD
EN 60027-2
NORME EUROPÉENNE
April 2007
EUROPÄISCHE NORM
ICS 01.060 Supersedes HD 60027-2:2003
English version
Letter symbols to be used in electrical technology -
Part 2: Telecommunications and electronics
(IEC 60027-2:2005)
Symboles littéraux à utiliser Formelzeichen
en électrotechnique - für die Elektrotechnik -
Partie 2: Télécommunications Teil 2: Telekommunikation
et électronique und Elektronik
(IEC 60027-2:2005)
(CEI 60027-2:2005)

This European Standard was approved by CENELEC on 2007-04-01. CENELEC 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

application 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 Secretariat 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 Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,

Sweden, Switzerland and the United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, 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
---------------------- Page: 3 ----------------------
SIST EN 60027-2:2008
EN 60027-2:2007 - 2 -
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 Procedure 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 that 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 60027-6.
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
Annex 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.
__________
---------------------- Page: 4 ----------------------
SIST EN 60027-2:2008
- 3 - EN 60027-2:2007
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application of this document. For dated

references, only the edition cited applies. For undated references, the latest edition of the referenced

document (including any amendments) applies.

NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD

applies.
Publication Year Title EN/HD Year
IEC 60027-1 1992 Letter symbols to be used in electrical EN 60027-1 2006
technology -
Part 1: General
IEC 60027-3 2002 Letter symbols to be used in electrical EN 60027-3 2007
technology -
Part 3: Logarithmic and related quantities,
and their units
IEC 60050-101 1998 International Electrotechnical Vocabulary - -
(IEV) -
Part 101: Mathematics
IEC 60050-131 2002 International Electrotechnical Vocabulary - - -
Part 131: Circuit theory
IEC 60050-191 1990 International Electrotechnical Vocabulary - -
(IEV) -
Chapter 191: Dependability and quality of
service
IEC 60050-351 1998 International Electrotechnical Vocabulary - -
(IEV) -
Part 351: Automatic control
IEC 60050-702 1992 International electrotechnical vocabulary - -
(IEV) -
Chapter 702: Oscillations, signals and related
devices
IEC 60050-704 1993 International electrotechnical vocabulary - -
(IEV) -
Chapter 704: Transmission
IEC 60050-705 1995 International Electrotechnical Vocabulary - -
(IEV) -
Chapter 705: Radio wave propagation
IEC 60050-712 1992 International Electrotechnical Vocabulary - -
(IEV) -
Chapter 712: Antennas
EN 60027-1 is based on IEC 60027-1:1995 (Reprint) + A1:1997.
---------------------- Page: 5 ----------------------
SIST EN 60027-2:2008
EN 60027-2:2007 - 4 -
Publication Year Title EN/HD Year
IEC 60050-713 1998 International Electrotechnical Vocabulary - -
(IEV) -
Part 713: Radiocommunications: transmitters,
receivers, networks and operation
IEC 60050-715 1996 International Electrotechnical Vocabulary - -
(IEV) -
Chapter 715: Telecommunication networks,
teletraffic and operation
IEC 60050-721 1991 International Electrotechnical Vocabulary - -
(IEV) -
Chapter 721: Telegraphy facsimile and data
communication
IEC 60050-722 1992 International electrotechnical vocabulary - -
(IEV) -
Chapter 722: Telephony
IEC 60050-723 1997 International Electrotechnical Vocabulary - -
(IEV) -
Chapter 723: Broadcasting: Sound, television
and data
IEC 60050-725 1994 International Electrotechnical Vocabulary - -
(IEV) -
Chapter 725: Space radiocommunications
IEC 60050-726 1982 International electrotechnical vocabulary - -
(IEV) -
Part 726: Transmission lines and waveguides
IEC 60050-731 1991 International Electrotechnical Vocabulary - -
(IEV) -
Chapter 731: Optical fibre communication
IEC 60122-1 2002 Quartz crystal units of assessed quality - EN 60122-1 2002
Part 1: Generic specification
IEC 60375 2003 Conventions concerning electric and EN 60375 2003
magnetic circuits
IEC 60747 Series Semiconductor devices - -
IEC 60747-1 1983 Semiconductor devices - - -
Part 1: General
IEC 60748 Series Semiconductor devices - - -
Integrated circuits
IEC 60748-1 2002 Semiconductor devices - Integrated circuits - - -
Part 1:General
IEC 61703 2001 Mathematical expressions for reliability, EN 61703 2002
availability, maintainability and maintenance
support terms
IEC/TR 61931 1998 Fibre optic - Terminology - -
ISO/IEC 2382-16 1996 Information technology - Vocabulary - - -
Part 16: Information theory
---------------------- Page: 6 ----------------------
SIST EN 60027-2:2008
- 5 - EN 60027-2:2007
Publication Year Title EN/HD Year
ISO 31-0 1992 Quantities and units - - -
Part 0: General principles
ISO 31-11 1992 Quantities and units - - -
Part 11: Mathematical signs and symbols for
use in the physical sciences and technology
---------------------- Page: 7 ----------------------
SIST EN 60027-2:2008
---------------------- Page: 8 ----------------------
SIST EN 60027-2:2008
NORME CEI
INTERNATIONALE
IEC
60027-2
INTERNATIONAL
Troisième édition
STANDARD
Third edition
2005-08
Symboles littéraux à utiliser en électrotechnique –
Partie 2:
Télécommunications et électronique
Letter symbols to be used in electrical
technology –
Part 2:
Telecommunications and electronics
 IEC 2005 Droits de reproduction réservés  Copyright - all rights reserved

Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in any

utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including

électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from

microfilms, sans l'accord écrit de l'éditeur. the publisher.

International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland

Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch

CODE PRIX
PRICE CODE
Commission Electrotechnique Internationale
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
Pour prix, voir catalogue en vigueur
For price, see current catalogue
---------------------- Page: 9 ----------------------
SIST EN 60027-2:2008
60027-2  IEC:2005 – 3 –
CONTENTS

FOREWORD...........................................................................................................................5

1 Scope...............................................................................................................................9

2 Normative references .......................................................................................................9

3 General concepts ...........................................................................................................13

3.1 General .................................................................................................................13

3.2 Linear networks.....................................................................................................35

3.2.1 General .....................................................................................................35

3.2.2 Two-port linear networks under sinusoidal conditions ................................35

3.2.3 n-port linear networks under sinusoidal conditions .....................................53

3.3 Line transmission of signals and telephony............................................................65

3.3.1 General .....................................................................................................65

3.3.2 Line transmission ......................................................................................65

3.3.3 Subscripts for line transmission .................................................................67

3.3.4 Telephony .................................................................................................69

3.3.5 Subscripts for telephony ............................................................................71

3.4 Waveguide propagation.........................................................................................73

3.4.1 Frequency and wavelength in a waveguide................................................73

3.4.2 Characteristic and normalized impedance and admittance in general

(unbounded space, waveguide or transmission line) ..................................73

3.4.3 Impedance and admittance at a point in a substance.................................75

3.4.4 Impedance and admittance at a point in vacuum .......................................75

3.4.5 Impedance and admittance of a waveguide ...............................................77

3.5 Radiocommunications ...........................................................................................79

3.5.1 General .....................................................................................................79

3.5.2 General and tropospheric propagation .......................................................79

3.5.3 Ionospheric propagation ............................................................................83

3.5.4 Antennas ...................................................................................................85

3.5.5 Radio links ................................................................................................93

3.6 Optical fibre communication ..................................................................................97

3.7 Television............................................................................................................107

3.8 Data processing and data transmission ...............................................................111

3.8.1 Teletraffic ................................................................................................111

3.8.2 Data processing and digital transmission.................................................113

3.8.3 Prefixes for binary multiples ....................................................................121

3.9 Information theory ...............................................................................................123

3.10 Dependability ......................................................................................................129

3.11 Equivalent circuits of piezoelectric crystal units ...................................................133

3.12 Semiconductor devices .......................................................................................141

3.13 Electroacoustics ..................................................................................................141

---------------------- Page: 10 ----------------------
SIST EN 60027-2:2008
60027-2  IEC:2005 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
LETTER SYMBOLS TO BE USED IN ELECTRICAL TECHNOLOGY –
Part 2: Telecommunications and electronics
FOREWORD

1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising

all national electrotechnical committees (IEC National Committees). The object of IEC is to promote

international co-operation on all questions concerning standardization in the electrical and electronic fields. To

this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,

Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC

Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested

in the subject dealt with may participate in this preparatory work. International, governmental and non-

governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely

with the International Organization for Standardization (ISO) in accordance with conditions determined by

agreement between the two organizations.

2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international

consensus of opinion on the relevant subjects since each technical committee has representation from all

interested IEC National Committees.

3) IEC Publications have the form of recommendations for international use and are accepted by IEC National

Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC

Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any

misinterpretation by any end user.

4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications

transparently to the maximum extent possible in their national and regional publications. Any divergence

between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in

the latter.

5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any

equipment declared to be in conformity with an IEC Publication.

6) All users should ensure that they have the latest edition of this publication.

7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and

members of its technical committees and IEC National Committees for any personal injury, property damage or

other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and

expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC

Publications.

8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is

indispensable for the correct application of this publication.

9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of

patent rights. IEC shall not be held responsible for identifying any or all such patent rights.

International Standard IEC 60027-2 has been prepared by IEC technical committee 25:

Quantities and units, and their letter symbols.

This third edition cancels and replaces the second edition published in 2000. This third edition

constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:

a) it contains a revision of some clauses of the first edition that were not technically revised

in the second edition;
b) it contains a revision of Clause 8 which is now Clause 10;

c) it contains some new clauses dealing with subjects that were not previously considered;

d) former Clause 10 will be given in another part of IEC 60027;
e) former Clause 11 will be revised as IEC 60027-6.
---------------------- Page: 11 ----------------------
SIST EN 60027-2:2008
60027-2  IEC:2005 – 7 –
The text of this standard is based on the following documents:
FDIS Report on voting
25/298/FDIS 25/304/RVD

Full information on the voting for the approval of this standard can be found in the report on

voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

IEC 60027 consists of the following parts, under the general title Letter symbols to be used in

electrical technology:
Part 1: General
Part 2: Telecommunications and electronics
Part 3: Logarithmic and related quantities, and their units
Part 4: Symbols for quantities to be used for rotating electrical machines
Part 6: Control technology
Part 7: Physiological quantities and units

The committee has decided that the contents of this publication will remain unchanged until

the maintenance result date T indicated on the IEC web site under Thttp://webstore.iec.ch T in the

data related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
---------------------- Page: 12 ----------------------
SIST EN 60027-2:2008
60027-2  IEC:2005 – 9 –
LETTER SYMBOLS TO BE USED IN ELECTRICAL TECHNOLOGY –
Part 2: Telecommunications and electronics
1 Scope

This part of 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 references, 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 60050-101:1998, 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 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 Electrotechnical 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, Telecommunication 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 Vocabulary – Part 723: Broadcasting:

sound, television, data
---------------------- Page: 13 ----------------------
SIST EN 60027-2:2008
60027-2  IEC:2005 – 11 –

IEC 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, International 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
IEC 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 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 symbols 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" covers SI units and other units coherent with the

SI, such as bar and neper.
---------------------- Page: 14 ----------------------
SIST EN 60027-2:2008
60027-2  IEC:2005 – 13 –
3 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 for 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 Entry Name of Chief Reserve Remarks Unit, coherent Other units Remarks
number number quantity symbol symbol with the SI
in IEV
Name SymbolName Symbol

101 101-12-02 signal The value of a signal is proportional to a physical quantity The unit depends on

S , s
702-04-01 considered as representing information, with an arbitrary
the kind of quantity
(generic term)
351-12-16 constituting the signal
scale. In this document, S and S are used for input and
1 2
(electric current,
output signals respectively; see IEC 60027-1:1992 for
voltage, pressure,
suitable subscripts. In cases where the type of signal
etc.).
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.

102 signal power "s" (lower case, upright) is used as subscript for "signal". watt W In a physical system,

P P
s sig
a signal power is
In signal theory, the term "instantaneous power" is by
always a physical
convention used for the square of the instantaneous value
power.
of a signal. This square is proportional to a physical power
if the signal is a field quantity
(see IEV 101-14-71, Note 1).
103 signal level In practice, a base for
L L , L S
s sig
L = log
the logarithm has to
ref
be specified.
where S and S are two signals of the same kind, S
ref ref
being a reference
103.1 702-07-04 absolute power neper Np decibel dB
1 P P
L = ln Np = 10 lg dB
level; power level
2 P P
ref ref
where P is a power and P is a reference power
ref
---------------------- Page: 15 ----------------------
SIST EN 60027-2:2008
60027-2  IEC:2005 – 15 –
Quantities Units
Item Entry Name of Chief Reserve Remarks Unit, coherent Other units Remarks
number number quantity symbol symbol with the SI
in IEV
Name SymbolName Symbol
103.2 702-07-06 absolute voltage neper Np decibel dB
U U
L = ln Np = 20 lg dB
level; voltage
U U
ref ref
level; absolute
tension level;
where U is a voltage and U is a reference voltage
ref
tension level
103.3 702-07-05 relative power neper Np decibel dB
L = L − L
r r,x P,x P,0
level
x refers to the measuring point and 0 to the reference
point
103.4 101-14-71 power spectral watt W/Hz In a physical system,
w( f )
N is
702-04-50 density per the power spectral
P = w( f )d f
used for
hertz density is always a
(for a signal or
the power
physical power
noise)
spectral where f is frequency.
spectral density.
density of
In signal theory, the term "instantaneous power" is by
a white
convention used for the square of the instantaneous value
noise
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).

104 101-14-63 noise Concerning upper-case and lower-case letters, see The unit depends on

N , n
S , s
n n
702-08-03 IEC 60027-1:1992, 2.1. the kind of quantity
(generic term)
constituting the noise
"n" (lower case, upright) is used as subscript for "noise".
(electric current,
The value of a noise is proportional to a physical quantity
voltage, pressure,
apparently not conveying information, with an arbitrary
etc.).
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.
105.1 702-08-51 equivalent noise Applies to a one-port network. volt V
voltage;
equivalent noise
tension
---------------------- Page: 16 ----------------------
SIST EN 60027-2:2008
60027-2  IEC:2005 – 17 –
Quantities Units
Item Entry Name of Chief Reserve Remarks Unit, coherent Other units Remarks
number number quantity symbol symbol with the SI
in IEV
Name SymbolName Symbol
105.2 702-08-52 equivalent noise Applies to a one-port network. ohm
R , R
eq n
resistance; noise 2
resistance R =
4kT Δf
ref
where k is the Boltzmann constant, T is a reference
ref
temperature and Δf is the frequency bandwidth
considered.
106 702-08-54 spot noise Applies to a one-port network. kelvin K
T(f)
temperature
f is frequency
106.1 702-08-55 mean noise Applies to a one-port network. kelvin K
temperature
107 702-08-56 equivalent spot Applies to a two-port network. kelvin K
T ( f )
noise
f is frequency
temperature
107.1 702-08-58 mean equivalent Applies to a two-port network. kelvin K
T eq
noise
temperature;
mean noise
temperature
107.2 702-08-57 spot noise factor Applies to a two-port network. one 1
F( f )
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 noise were input thermal noise at a reference
temperature T :
ref
T ( f )
F( f ) = 1+
ref
where f is frequency.
---------------------- Page: 17 ----------------------
SIST EN 60027-2:2008
60027-2  IEC:2005 – 19 –
Quantities Units
Item Entry Name of Chief Reserve Remarks Unit, coherent Other units Remarks
number number quantity symbol symbol with the SI
in IEV
Name SymbolName Symbol
107.3 spot noise factor neper Np decibel dB
702-08-57
F ( f ) 1
F()f = ln F()f Np = 10 lg F( f) dB
(Note 2)
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 expres
...

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