SIST EN 60835-2-2:2002

Methods of measurement for equipment used in digital microwave radio transmission systems -- Part 2: Measurements on radio-relay systems -- Section 2: Antenna

Gives methods of measurement of the electrical characteristics of antennas used in terrestrial radio-relay systems at frequencies above 1 GHz. The methods are suitable for both line-of-sight and tropospheric scatter radio-relay systems using linear polarization.

Meßverfahren für Geräte in digitalen Mikrowellen-Funkübertragungssystemen -- Teil 2: Messungen an terrestrischen Richtfunksystemen -- Hauptabschnitt 2: Antenne

Méthodes de mesure applicables au matériel utilisé pour les systèmes de transmission numérique en hyperfréquence -- Partie 2: Mesures applicables aux faisceaux hertziens terrestres -- Section 2: Antennes

Traite des méthodes de mesures applicables aux caractéristiques électriques des antennes utilisées dans les systèmes de faisceaux hertziens terrestres à des fréquences supérieures à 1 GHz. Les méthodes sont applicables à la fois aux faisceaux hertziens en visibilité directe et en diffusion troposphérique utilisant une polarisation linéaire.

Methods of measurement for equipment used in digital microwave radio transmission systems - Part 2: Measurements on radio-relay systems - Section 2: Antenna (IEC 60835-2-2:1994)

General Information

• Status: Published
• Publication Date: 30-Sep-2002
• ICS: 33.060.30 - Radio relay and fixed satellite communications systems
• Technical Committee: OMS - Equipment used in mobile services and satelite comunication systems
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Oct-2002
• Due Date: 01-Oct-2002
• Completion Date: 01-Oct-2002
• Ref Project: EN 60835-2-2:1994 - Methods of measurement for equipment used in digital microwave radio transmission systems - Part 2: Measurements on radio-relay systems - Section 2: Antenna

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 60835-2-2:2002
01-oktober-2002
Methods of measurement for equipment used in digital microwave radio
transmission systems - Part 2: Measurements on radio-relay systems - Section 2:
Antenna (IEC 60835-2-2:1994)
Methods of measurement for equipment used in digital microwave radio transmission
systems -- Part 2: Measurements on radio-relay systems -- Section 2: Antenna
Meßverfahren für Geräte in digitalen Mikrowellen-Funkübertragungssystemen -- Teil 2:
Messungen an terrestrischen Richtfunksystemen -- Hauptabschnitt 2: Antenne
Méthodes de mesure applicables au matériel utilisé pour les systèmes de transmission
numérique en hyperfréquence -- Partie 2: Mesures applicables aux faisceaux hertziens
terrestres -- Section 2: Antennes
Ta slovenski standard je istoveten z: EN 60835-2-2:1994
ICS:
33.060.30 Radiorelejni in fiksni satelitski Radio relay and fixed satellite
komunikacijski sistemi communications systems
SIST EN 60835-2-2:2002 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST EN 60835-2-2:2002

---------------------- Page: 2 ----------------------

SIST EN 60835-2-2:2002

---------------------- Page: 3 ----------------------

SIST EN 60835-2-2:2002

---------------------- Page: 4 ----------------------

SIST EN 60835-2-2:2002

---------------------- Page: 5 ----------------------

SIST EN 60835-2-2:2002

---------------------- Page: 6 ----------------------

SIST EN 60835-2-2:2002
NORME
CEI
INTERNATIONALE
IEC
60835-2-2
INTERNATIONAL
Première
édition
STAN DARD
First edition
1994-05
Méthodes de mesure applicables au matériel
utilisé pour les systèmes de transmission
numérique en hyperfréquence
Partie 2:
Mesures applicables aux faisceaux hertziens
terrestres
Section 2: Antenne
Methods of measurement for equipment used in
digital microwave radio transmission systems
Part 2:
Measurements on terrestrial radio-relay systems
Section 2: Antenna
© IEC 1994 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
utilisée sous quelque forme que ce soit et par aucun
any form or by any means, electronic or mechanical,
procédé, électronique ou mécanique, y compris la photo- including photocopying and microfilm, without permission in
copie et les microfilms, sans l'accord écrit de l'éditeur.
writing from the publisher.
International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: [phone] e-mail: inmail©iec.ch IEC web site http: //www.iec.ch
CODE PRIX
Commission Electrotechnique Internationale
PRICE CODE
International Electrotechnical Commission
IEC
MeiwayHaponHaR 3neMTpOTexHH4ecnaR HoMHCCHR
Pour prix, voir catalogue en vigueur
• •
For price, see current catalogue

---------------------- Page: 7 ----------------------

SIST EN 60835-2-2:2002
835-2-2 © IEC:1994 _ 3 –
CONTENTS
Page
FOREWORD 5
INTRODUCTION 7
Clause
1 Scope 9
2 Normative references 9
3 Definitions 9
4 Methods of measurement 15
4.1 Test-range considerations 15
4.2 Antenna gain 17
4.3 Radiation patterns 27
4.4 Cross-polarization discrimination 31
4.5 Return loss 33
4.6 Multi-port antenna isolation 35
5 Bibliography 35
Figures
1 Measurement of antenna gain by comparison with
a gain-reference antenna 37
2 Measurement of antenna gain by the direct method 39
3 Examples of presentation of results of antenna-gain measurement 41
4 Example of arrangement for the measurement of radiation pattern 43
5 Example of radiation patterns and their envelope 43

---------------------- Page: 8 ----------------------

SIST EN 60835-2-2:2002
835-2-2 © IEC:1994 –
5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
METHODS OF MEASUREMENT FOR
EQUIPMENT USED IN DIGITAL MICROWAVE
TRANSMISSION SYSTEMS -
Part 2: Measurements on terrestrial
radio-relay systems - Section 2: Antenna
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization
comprising all national electrotechnical committees (IEC National Committees). The object of the IEC is to
promote international cooperation on all questions concerning standardization in the electrical and
electronic fields. To this end and in addition to other activities, the IEC publishes International Standards.
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. The 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 the IEC on technical matters, prepared by technical committees on
which all the National Committees having a special interest therein are represented, express, as nearly as
possible, an international consensus of opinion on the subjects dealt with.
3) They have the form of recommendations for international use published in the form of standards, technical
reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
International Standard IEC 835-2-2 has been prepared by IEC by sub-committee 12E, of
IEC technical committee 12: Radiocommunications.
The text of this standard is based on the following documents:
DIS Report on Voting
12E(CO)158 12E(CO)163
Full information on the voting for the approval of this standard can be found in the report
on voting indicated in the above table.

---------------------- Page: 9 ----------------------

SIST EN 60835-2-2:2002
835-2-2 © IEC:1994 – 7 –
INTRODUCTION
Antennas are key elements of radio-relay systems. A satisfactory fade margin for such
systems is usually obtained by using high directivity, i.e. high-gain, antennas at both the
transmitter and receiver terminals of a radio link.
An antenna with a high directivity usually also has a narrow beam width main lobe which
can provide a useful measure of protection against reflected rays. These reflected rays
can lead to multipath fading.
Rapid sidelobe suppression away from the main lobe is often a requirement at radio-relay
system nodes to provide sufficient de-coupling between radio links which employ
frequency use and small angular separation between the line-of-sight paths.
Moreover, and especially for digital radio-relay systems, a high cross-polarization
discrimination is necessary to provide sufficient decoupling between adjacent orthogonally
polarized channels where the signal spectra overlap considerably, and between two
orthogonally polarized co-frequency channels, i.e. using the same nominal carrier
frequency.
If the antenna under test is installed with a radome in normal operation on a radio link, all
measurements should be performed with the radome fitted.

---------------------- Page: 10 ----------------------

SIST EN 60835-2-2:2002
835-2-2 ©
IEC:1994 - 9 -
METHODS OF MEASUREMENT FOR
EQUIPMENT USED IN DIGITAL MICROWAVE
TRANSMISSION SYSTEMS -
Part 2: Measurements on terrestrial
radio-relay systems - Section 2: Antenna
1 Scope
This section of IEC 835-2 gives methods of measurement of the electrical characteristics
of antennas used in terrestrial radio-relay systems at frequencies above 1 GHz.
The methods described are suitable for both line-of-sight and tropospheric scatter
radio-relay systems using linear polarization. This section does not consider methods of
measurement for passive repeaters or periscope antennas nor does it address systems
where the antenna cannot be measured separately.
2 Normative references
The following normative documents contain provisions which, through reference in this
text, constitute provisions of this section of IEC 835-2. At the time of publication, the
editions indicated were valid. All normative documents are subject to revision, and pa rties
to agreements based on this section of IEC 835-2 are encouraged to investigate the
possibility of applying the most recent editions of the normative documents indicated
below. Members of IEC and ISO maintain registers of currently valid International
Standards.
IEC 50, International Electrotechnical Vocabulary (IEV)
IEC 835-1-2: 1992,
Methods of measurement for equipment used in digital microwave
transmission systems - Part 1: Measurements common to terrestrial radio-relay systems
and satellite earth stations - Section 2: Basic characteristics
Definitions
For the purposes of this section of IEC 835-2, the following definitions apply.
Where a term is not defined in this section, the definition is assumed to be identical with
the definition given in the International Electrotechnical Vocabulary (IEV). In case of
conflict, the definition given here takes precedence.
NOTE - Characteristics for which methods of measurement are given are defined in the corresponding
measurement subclause.

---------------------- Page: 11 ----------------------

SIST EN 60835-2-2:2002
835-2-2 © IEC:1994 –11 –
3.1 Antenna
An antenna is defined as a device for coupling a transmission line to free-space for the
purpose of transmitting or receiving electromagnetic waves. It includes all the elements
affecting the radiation characteristics of the antenna, e.g. primary feed(s), including
polarization and/or frequency filters, reflectors, etc. It does not include the associated
transmission lines and other electrical components on the transmitter/receiver side of the
antenna terminals defined for measurement purposes. The antenna terminals must be
specified. The antenna may also include a radome.
3.2 Antenna assembly
The antenna assembly, as used here, includes the antenna and the provisions for
attaching it to the supporting structure. It may also include provisions for pointing the
antenna, when specified.
3.3 Antenna system
The antenna system includes the antenna assembly, the transmission lines and, if not
already contained in the antenna, the components necessary for radiating the
electromagnetic energy in the desired direction.
Radome
3.4
A protective cover of dielectric material for an antenna and/or its feed. A radome may also
be used to reduce the effects of wind loading.
3.5 Bore-sight direction
Bore-sight direction is the direction intended to produce maximum antenna gain and hence
maximum power transfer.
3.6 Antenna polarization
The polarization of the electric field vector in the far-field region of the electromagnetic
wave radiated by the antenna in the bore-sight direction.
Radio links exclusively use linear polarization, and most commonly vertical or horizontal
linear polarization.
3.7 Polarization tilt angle
The polarization tilt angle for a linearly polarized wave is defined as the angle between the
electric field vector and the nominal polarization vector, in a plane perpendicular to the
direction of propagation.
3.8 Nominal polarization
The nominal polarization of an antenna is the intended polarization of the antenna. Two
antennas are said to be nominally co-polarized if their nominal polarizations are identical.

---------------------- Page: 12 ----------------------

SIST EN 60835-2-2:2002
835-2-2 © I EC:1994 – 13 –
3.9
Cross-polarization
Cross-polarization is defined as that polarization which is o
rthogonal to the nominal
polarization, as defined in 3.8. Two antennas are said to be nominally cross-polarized if
their nominal polarizations are o
rthogonal.
3.10 Single-polarization antenna
A single-polarization antenna is an antenna that radiates and/or receives only one plane of
polarization. A single-polarized antenna normally has only one po
rt for connection to the
associated transmission line.
3.11
Dual-polarized antenna
A dual-polarized antenna is an antenna that radiates and/or receives two planes of
polarization. The two planes are intended to be mutually o rthogonal. A dual-polarized
antenna normally has two po rts. The two po
rts may be at the antenna, or at the
transmitter/receiver end of the antenna transmission line if the line is capable of
supporting two o rt
hogonal transmission modes.
3.12 Multi-band antenna
An antenna which radiates and/or receives simultaneously in two or more frequency
bands. Such an antenna may also be a dual-polarized antenna and operate simultaneously
with ort
hogonal polarizations in two or more frequency bands.
3.13
Effective area of an antenna (in a given direction) (Ae)
The effective area of an antenna in a given direction is the ratio between the power
delivered to a matched load at the antenna terminals
(Pr), and the power per unit area (S)
in a polarization-matched plane wave incident on the antenna, i.e.
Pr
Ae (3-1)
S
3.14 Antenna efficiency
The antenna efficiency is the ratio of the maximum effective area to the projected area of
the antenna in a plane perpendicular to the direction of maximum radiation. The maximum
effective area is related to the maximum gain as defined in 4.2.1.
3.15
Gain-reference antenna
A gain-reference antenna is an antenna of closely reproducible specified construction
having a gain which can be determined by calculation and, if required, confirmed by
measurement as being sufficiently consistent for use as a transfer standard for
antenna-gain measurement.

---------------------- Page: 13 ----------------------

SIST EN 60835-2-2:2002
835-2-2 © IEC:1994 –15 –
4 Methods of measurement
4.1
Test range considerations
The "ideal" test range for determining far-field antenna pe
rformance should provide a
plane wave of uniform amplitude and phase which completely illuminates the ape rture of
the antenna under test.
The standard approach for an "ideal" test range is the so-called "free-space test range".
Such a test-range is often quite long, e.g. several hundreds of metres for test ranges
suitable for the measurement of typical radio link antennas. Free-space test ranges are
therefore usually constructed outdoors.
The minimum recommended test-range length, or far-field distance, is usually 2D 2/? ,
D
where is the largest ape rture dimension either of the antenna under test or of the source
antenna, and X is the wavelength.
When this is the case, the maximum path-length difference between the centre of the
source antenna to the centre of the antenna under test and the centre of the source
antenna to any point on the ape
rture-plane of the antenna under test is X/16 and the
maximum error is then negligible.
In some cases, the above minimum far-field distance is not sufficient and then a gain
correction factor may be necessary.
In some other cases, e.g. for antennas with strongly tapered ape rture illumination, smaller
minimum distances, for instance D2
/X, may be permissible.
In free-space test ranges, attempts are always made to suppress the effects of reflected
signals from the surroundings. These include reflections from the test range su
rface itself
in the case of elevated test ranges, i.e. the earth, from the source and test-antenna
support towers or buildings and from other nearby reflecting objects. If the rearwards-
pointing radiation pattern of the antenna under test is to be measured accurately, as is
usually the case for radio link antennas, reflections from points situated at the rear of the
antenna under test should also be negligible, or should be evaluated for correction.
Further details on test-range design and siting requirements in relation to far-field
measurements can be found in reference [1]*.
One other type of test range that may be implemented within an anechoic chamber should
be mentioned. This is the "compact test range", which, in its most basic form, uses a large
offset paraboloidal reflector, with dimensions at least three times larger than those of the
antenna under test.
The reference in square brackets refers to clause 5: Bibliography.

---------------------- Page: 14 ----------------------

SIST EN 60835-2-2:2002
835-2-2 ©
IEC:1994 –17 –
The source antenna is installed at the focus of the offset paraboloid reflector and a plane
wave is then obtained at a very short distance from the source. However, several
imperfections exist with this technique which have to be taken into account. For example,
depolarization of the incident wave due to the curved reflector leads to errors in
cross-polarization measurements made outside the boresight of the antenna under test,
reflector interactions can occur between the reflector of the antenna under test and the
source antenna reflector, etc.
4.2 Antenna gain
4.2.1 Definition and general considerations
The gain of a perfectly matched transmitting antenna is the ratio of the power density
produced in the far-field region, in a given direction from the antenna, to the power density
which would be produced at the same distance by an isotropic antenna fed by the same
power from the same source as the antenna under test.
For receiving antennas, a definition of maximum gain can be derived from that of effective
e) by the relation:
area (A
4n Ae
(4-1)
G =
x2
where ? is the wavelength.
For the same antenna used for transmitting and receiving at the same frequency and with
the same terminals, the gains defined above for transmitting and for receiving will be equal
if the antenna is reciprocal.
Unless otherwise specified, gain will be defined as the maximum gain, i.e. gain in the
maximum gain, i.e. gain in the bore-sight direction.
Two methods of gain measurement are considered in this section:
measurement of the gain of an antenna by comparison with a gain-reference
1)
antenna,
and an alternative, direct measurement, method, where,
2) the gain is calculated after measuring the transmitted signal power, the received
signal power, the calculated value of the test-range path loss and the gain of the
source or of the transmitting antenna.
4.2.2 Gain measurement by comparison with a gain-reference antenna
Subclauses 4.2.2.1 to 4.2.2.5 refer to the measurement of the gain of receiving antennas.
In cases where the gains of transmitting antennas are to be measured, the transmitting
source and the receiving electronic equipment shall be interchanged if the antenna is
non-reciprocal.

---------------------- Page: 15 ----------------------

SIST EN 60835-2-2:2002
835-2-2 ©
IEC:1994 - 19 -
4.2.2.1 General considerations
Gain measurement by comparison with a gain-reference antenna involves the comparison
of the signal level received by a gain-reference antenna and that received by the antenna
under test from the same distant radiating source.
The reference antenna should have a known gain and a VSWR should be low enough to
ensure negligible errors.
To minimize any errors associated with non-uniformities in the illuminating field the
gain-reference antenna and the antenna under test should be located as close to each
other as possible. Corrections should be applied to account for any remaining
non-uniformities in the illuminating fields, as outlined in 4.1.
Care must be taken to ensure that the effect of the structure associated with the antenna
under test, which may be large, does not significantly alter the characteristics of the
gain-reference antenna.
In cases where the incident field illuminating the ape
rture of the antenna under test
departs significantly from a plane wavefront having uniform amplitude and phase, a
power-transfer correction factor for each antenna is also required in order to accurately
establish the gain of the antenna under test.
NOTE - Generally, the physical dimensions, and hence gain, of the antenna under test are both greater
than those of the gain-reference antenna.
4.2.2.2
Gain-measurement accuracy
As this method involves only a comparison between two antennas, the absolute accuracy
of the power meter used is generally not impo rtant.
To minimize the errors associated with gain differences between the receiving equipment
and other active electronic equipment, e.g. recorders, involved in the measurements, a
single, common, set of receiving electronic equipment, recorders etc., is normally used for
both measurements with the gain-reference antenna and with the antenna under test.
Care must also be taken to minimize errors associated with gain drift in the receiv
...