SIST EN 60835-3-5:2002

SLOVENSKI STANDARD
01-oktober-2002
Methods of measurement for equipment used in digital microwave radio
transmission systems - Part 3: Measurements on satellite earth stations - Section
5: Up- and down-converters (IEC 60835-3-5:1994)
Methods of measurement for equipment used in digital microwave radio transmission
systems -- Part 3: Measurements on satellite earth stations -- Section 5: Up- and down-
converters
Meßverfahren für Geräte in digitalen Mikrowellen-Funkübertragungssystemen -- Teil 3:
Messungen an Satelliten-Erdfunkstellen -- Hauptabschnitt 5: Sende- und
Empfangsumsetzer
Méthodes de mesure applicables au matériel utilisé pour les systèmes de transmission
numérique en hyperfréquence -- Partie 3: Mesures applicables aux stations terriennes de
télécommunications par satellite -- Section 5: Convertisseurs élévateurs et abaisseurs de
fréquence
Ta slovenski standard je istoveten z: EN 60835-3-5:1994
ICS:
33.060.30 Radiorelejni in fiksni satelitski Radio relay and fixed satellite
komunikacijski sistemi communications systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

NORME CEI
INTERNATIONALE IEC
60835-3-5
INTERNATIONAL
Première édition
STANDARD
First edition
1994-04
Méthodes de mesure applicables au matériel
utilisé pour les systèmes de transmission
numérique en hyperfréquence
Partie 3:
Mesures applicables aux stations terriennes
de télécommunications par satellite
Section 5: Convertisseurs élévateurs et
abaisseurs de fréquence
Methods of measurement for equipment used in
digital microwave radio transmission systems
Part 3:
Measurements on satellite earth stations
Section 5: Up- and down-converters
© IEC 1994 Droits de reproduction réservés — Copyright - all rights reserved
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835-3-5 © IEC:1994 - 3 -
CONTENTS
Page
FOREWORD 7
Clause
1 Scope 9
2 Normative references 9
3 General 11
3.1 Up-converter 11
3.2 Down-converter 11
4 Input and output return loss 11
5 Input and output level or power 13
6 Gain 13
6.1 Gain stability 13
6.2 Gain compression 13
7 Automatic gain control (a.g.c.) 15
7.1 Definition and general considerations 15
7.2 Method of measurement 15
7.3 Presentation of results 15
7.4 Details to be specified 17
8 Amplitude modulation/phase modulation conversion factor 17
9 Amplitude/frequency characteristic 17
10 Group delay/frequency characteristic 17
11 Spurious output signals (including harmonics) 17
12 Intermodulation products 17
13 Phase noise 17
13.1 Definition and general considerations 17
13.2 Method of measurement using a spectrum analyser 19
13.3 Alternative method of measurement for down-converters 19
13.4 Alternative method of measurement for up-converters
13.5 Presentation of results 21
13.6 Details to be specified 21

835-3-5 © IEC:1994 – 5 —
Clause Page
14 Noise figure 23
14.1 Up-converter
14.2 Down-converter
14.3 Calibration
14.4 Correction of the measurement data
14.5 Presentation of results
14.6 Details to be specified
15 Local oscillator frequency
Figures 29
835-3-5 © IEC:1994 - 7 -
INTERNATIONAL ELECTROTECHNICAL COMMISSION
METHODS OF MEASUREMENT FOR EQUIPMENT
USED IN DIGITAL MICROWAVE RADIO
TRANSMISSION SYSTEMS
Part 3: Measurements on satellite earth stations
Section 5: Up- and down -converters
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 835-3-5 has been prepared by sub-committee 12E: Radio-relay
and fixed satellite communications systems, of IEC technical committee 12: Radiocommuni-
cations.
The text of this standard is based on the following documents:
DIS
Report on Voting
12E(CO)147 12E(CO)162
Full information on the voting for the approval of this standard can be found in the report
on voting indicated in the above table.

835-3-5 © IEC:1994 - 9 -
METHODS OF MEASUREMENT FOR EQUIPMENT
USED IN DIGITAL MICROWAVE RADIO
TRANSMISSION SYSTEMS
Part 3: Measurements on satellite earth stations
Section 5: Up- and down-converters
1 Scope
This section of IEC 835-3 describes methods of measurement of the electrical character-
istics of up-converters and down-converters used in satellite earth station transmitters and
receivers with digital modulation.
2 Normative references
The following normative documents contain provisions which, through reference in this
text, constitute provisions of this section of IEC 835-3. 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 835-3 are encouraged to investigate the possi-
bility 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 835-1-1: 1990,
Methods of measurement for equipment used in digital microwave
radio transmission systems - Part 1: Measurements common to terrestrial radio-relay
systems and satellite earth stations - Section 1: General
IEC 835-1-2: 1992,
Methods of measurement for equipment used in digital microwave
radio transmission systems - Pa rt
1: Measurements common to terrestrial radio-relay
systems and satellite earth stations - Section 2: Basic characteristics
IEC 835-1-3: 1992.
Methods of measurement for equipment used in digital microwave
radio transmission systems - Part 1: Measurements common to terrestrial radio-relay
systems and satellite earth stations - Section 3: Transmission characteristics
IEC 835-3-4: 1993,
Methods of measurement for equipment used in digital microwave
radio transmission systems - Part 3: Measurements on satellite earth stations - Section 4:
Low noise amplifier
835-3-5 © IEC:1994
3 General
3.1 Up-converter
An up-converter is a subsystem of the transmitting chain which converts an i.f. signal (e.g.
in the frequency bands 70 MHz or 140 MHz) to an r.f. signal (e.g. in the frequency bands
6 GHz or 14 GHz).
Figure 1 shows a block diagram of a typical double conversion up-converter. Note that in
some cases only one mixing stage may be used.
The up-converter shown in figure 1 consists principally of a first i.f. stage, a first mixer, a
first local oscillator and a first i.f. filter, a second i.f. stage, a second mixer, a second local
oscillator and an r.f. output filter. The filters are provided after the mixers to suppress the
local oscillator signals and other spurious signals which may be present at the output of
the mixers. I.F. equalizers may be provided for correcting the up-converter amplitude/
frequency and/or group delay/frequency characteristics but additional, separate, i.f.
amplitude and group-delay equalizers may be provided to equalize the earth station trans-
mit characteristic and to pre-correct for the satellite group-delay and amplitude/frequency
response. A variable attenuator is included to adjust the gain of the up-converter.
3.2 Down-converter
A down-converter is a subsystem of the receiving chain which converts an r.f. signal (e.g.
in the frequency bands 4 GHz or 11
GHz) to an i.f. signal (e.g. in the frequency bands
70 MHz or 140 MHz). Figure 2 shows a block diagram of a typical double-conversion
down-converter. Note that in some cases only one mixing stage may be used.
The down-converter shown in figure 2 consists principally of an r.f. filter, a first mixer, a
first local oscillator, a first i.f. stage, a first i.f. filter, a second mixer, a second local oscil-
lator and a second i.f. stage. The i.f. filters are provided after the mixers to suppress the
local oscillator signals and other spurious signals which may be present at the output. 1.F.
equalizers may be provided for correcting the down-converter amplitude/frequency and/or
group delay/frequency characteristics.
Equalization of the receiving chain is normally carried out by individual equalizers. Auto-
matic gain control (a.g.c.) may be provided to maintain a constant i.f. level with variations
in the r.f. input level.
4 Input and output return loss
See IEC 835-1-2.
835-3-5 © IEC:1994 - 13 -
NOTE - Special care should be taken that unwanted signals are excluded by the measuring equipment,
particularly those from the local oscillator. During the measurement the oscillator power should be adjusted
to its nominal value.
5 Input and output level or power
See IEC 835-1-2.
6 Gain
See IEC 835-1-2.
The gain is usually adjustable and should be measured at specified gain control setting.
NOTE - The input and output frequencies are different and this should be taken into account in the test
arrangement.
6.1 Gain stability
See IEC 835-3-4.
6.2 Gain compression
6.2.1 Definition
Gain compression is the ratio, in decibels, between the gain measured at low signal levels
and the gain measured at a specified test output and input level. It is usual to specify the
output level at which gain compression is 1 dB.
6.2.2 Method of measurement
The gain as defined above is measured at different input signal levels and gain compres-
sion is then calculated from the values obtained.
For the measurement of small gain compressions, the test equipment used needs to be of
high accuracy and stability. If a filter is included to measure the wanted signal, its insertion
loss needs to be taken into account in the presentation of the results. A selective level
meter may be used to select the wanted signal for measurement. The gain compression
can then be evaluated from the curve which relates output level to input level.
NOTES
1 If the converter provides a.g.c., this control needs to be switched off and the i.f. gain adjusted
manually to obtain the specified test output level at the nominal input level(s).
2 To avoid errors due to power fluctuations, it may be necessary to use two power meters which are
read simultaneously – one meter being connected to the input port and the other to the output port. The
use of differential measuring equipment enables the measurement of gain compression to be made with
greater accuracy than is achievable using two power meters.
6.2.3 Presentation of results
Preferably the results should be presented as a graph of power gain versus input power.

835-3-5 ©IEC:1994 - 15 -
When the results are not presented graphically, they should be given as in the following
example:
"The gain compression at output level of . dBm is . dB."
6.2.4 Details to be specified
The following items should be included, as required, in the detailed equipment specifi-
cation:
a)
input level(s) and frequency;
b) output level(s) and frequency;
c) permitted gain compression.
7 Automatic gain control (a.g.c.)
If an a.g.c. is employed its pe rf
ormance can be measured as described below.
7.1 Definition and general considerations
The a.g.c. characteristic of the down-converter is given by the i.f. output level as a
function of the r.f. input level, both expressed in dBm at the nominal input frequency. This
is the steady-state characteristic which is measured by manually changing the r.f. input
level.
7.2
Method of measurement
The input port of the down-converter is connected to the output po
rt of an r.f. generator
tuned to the centre frequency of the passband of the down-converter. The i.f. output of the
down-converter is connected to an i.f. level meter presenting a nominal load impedance,
while the control voltage is measured by a d.c. voltmeter. The r.f. signal generator
attenuator is initially adjusted
...