prEN IEC 60728-103:2025

SLOVENSKI STANDARD
01-september-2025
Aktivna širokopasovna oprema za kabelska omrežja z izključno digitalnimi signali
Active wideband equipment for cable networks with digital signals only
Équipement actif à large bande pour les réseaux câblés avec des signaux numériques
uniquement
Ta slovenski standard je istoveten z: prEN IEC 60728-103:2025
ICS:
33.060.40 Kabelski razdelilni sistemi Cabled distribution systems
33.170 Televizijska in radijska Television and radio
difuzija broadcasting
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

100/4351/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 60728-103 ED1
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2025-07-25 2025-10-17
SUPERSEDES DOCUMENTS:
100/4133/CD, 100/4162A/CC
IEC TA 5 : CABLE NETWORKS FOR TELEVISION SIGNALS, SOUND SIGNALS AND INTERACTIVE SERVICES
SECRETARIAT: SECRETARY:
Japan Mr Hiroo Tamura
OF INTEREST TO THE FOLLOWING COMMITTEES: HORIZONTAL FUNCTION(S):

ASPECTS CONCERNED:
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft for
Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.
This document is still under study and subject to change. It should not be used for reference purposes.
Recipients of this document are invited to submit, with their comments, notification of any relevant patent rights of which
they are aware and to provide supporting documentation.
Recipients of this document are invited to submit, with their comments, notification of any relevant “In Some Countries”
clauses to be included should this proposal proceed. Recipients are reminded that the CDV stage is the final stage for
submitting ISC clauses. (SEE AC/22/2007 OR NEW GUIDANCE DOC).

TITLE:
Active wideband equipment for cable networks with digital signals only

PROPOSED STABILITY DATE: 2029
NOTE FROM TC/SC OFFICERS:
this electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee
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IEC CDV 60728-103 © IEC 2025
1 CONTENTS
2 FOREWORD . 4
3 INTRODUCTION . 6
4 1 Scope . 7
5 2 Normative references . 7
6 3 Terms, definitions, symbols and abbreviated terms . 8
7 3.1 Terms and definitions . 8
8 3.2 Symbols . 11
9 3.3 Abbreviated terms . 13
10 4 Methods of measurement . 13
11 4.1 General . 13
12 4.2 Linear distortion . 14
13 4.2.1 Return loss . 14
14 4.2.2 Group delay variation . 14
15 4.3 Non-linear distortion. 15
16 4.3.1 General . 15
17 4.3.2 Types of measurements . 16
18 4.3.3 Intermodulation . 16
19 4.3.4 Method of measurement of non-linearity for pure digital channel load for
20 channel loads up to 1 218 MHz . 19
21 4.3.5 Method of measurement of non-linearity for pure digital channel load for
22 channel loads up to 1 794 MHz . 23
23 4.3.6 Hum modulation of carrier . 27
24 4.4 Noise figure . 31
25 4.4.1 General . 31
26 4.4.2 Equipment required . 31
27 4.4.3 Connection of equipment . 32
28 4.4.4 Measurement procedure . 32
29 4.5 Crosstalk attenuation . 32
30 4.5.1 Crosstalk attenuation for loop-through ports . 32
31 4.5.2 Crosstalk attenuation for output ports . 33
32 4.6 Immunity to surge voltages . 34
33 4.6.1 General . 34
34 4.6.2 Equipment required . 35
35 4.6.3 Connection of equipment . 35
36 4.6.4 Measurement procedure . 35
37 5 Performance requirements. 35
38 5.1 General requirements . 35
39 5.2 Safety . 35
40 5.3 Electromagnetic compatibility (EMC) . 36
41 5.4 Frequency range . 36
42 5.5 Impedance and return loss . 36
43 5.6 Gain . 36
44 5.6.1 Minimum and maximum gain . 36
45 5.6.2 Gain control . 36
46 5.6.3 Slope and slope control . 36
47 5.7 Flatness . 36
IEC CDV 60728-103 © IEC 2025
48 5.8 Test points . 37
49 5.9 Noise figure . 37
50 5.10 Non-linear distortion. 37
51 5.10.1 General . 37
52 5.10.2 Second-order distortion . 37
53 5.10.3 Third order distortion . 37
54 5.10.4 Maximum operating level for pure digital channel load . 37
55 5.11 Hum modulation . 38
56 5.12 Power supply . 38
57 5.13 Environmental . 38
58 5.13.1 General . 38
59 5.13.2 Transportation . 38
60 5.13.3 Installation or maintenance . 38
61 5.13.4 Operation . 38
62 5.14 Marking . 39
63 5.14.1 Marking of ports . 39
64 5.15 Requirements for multi-switches . 39
65 5.15.1 Control signals for multi-switches . 39
66 5.15.2 Amplitude frequency response flatness . 39
67 5.15.3 Return loss . 39
68 5.15.4 Through loss . 39
69 5.15.5 Isolation . 39
70 5.15.6 Crosstalk attenuation . 39
71 5.15.7 Satellite IF to terrestrial signal isolation . 39
72 5.16 Immunity to surge voltages . 40
73 5.16.1 Degrees of testing levels . 40
74 5.16.2 Recommendation of testing level degree . 40
75 Annex A (normative) Test carriers, levels and intermodulation products . 41
76 A.1 General considerations on intermodulation products . 41
77 A.2 Two signal tests for second- and third-order products . 42
78 A.2.1 Intermodulation products with test signals at frequencies  and  ,
a b
79 see Table A.3 . 42
80 A.2.2 Signal levels . 42
81 A.3 Three signal tests for third order products – Intermodulation products with
82 test signals at frequencies  ,  and  , see Table A.4 and Figure A.3 . 43
a b c
83 Annex B (informative) Measurement errors that occur due to mismatched equipment . 45
84 Annex C (informative) Examples of measurement channels . 46
85 C.1 Operating frequency range 110 MHz to 1 006 MHz . 46
86 C.2 Operating frequency range 258 MHz to 1 218 MHz . 46
87 Bibliography . 47
89 Figure 1 – Basic arrangement of test equipment for evaluation of the ratio of signal to
90 intermodulation product . 19
91 Figure 3 – BER measurement test configuration . 22
92 Figure 3 – CINR measurement test setup . 28
93 Figure 4 – Plot of CINR in dB curve (forward path) as function of EUT channel output
94 signal level in dB(V) . 29
95 The carrier to hum ratio (R ) is given by following formula (4) . 30
CH
IEC CDV 60728-103 © IEC 2025
96 Figure 5 – Carrier to hum ratio . 30
97 Figure 6 – Test set-up for local-powered objects . 31
98 Figure 7 – Test set-up for remote-powered objects . 31
99 Figure 8 – Spectrum analyser display . 32
100 Figure 9 – Measurement of noise figure . 34
101 Figure 10 – Measurement of crosstalk attenuation for loop through ports of multi-
102 switches. 36
103 Figure 11 – Measurement set-up for surge immunity test . 37
104 Figure A.1 – An example showing products formed when 2 >  . 45
a b
105 Figure A.2 – An example showing products formed when 2 <  . 45
a b
106 Figure A.3 – Products of the form  ±  ±  . 46
a b c
107 Figure B.1 – Error concerning return loss measurement . 47
108 Figure B.2 – Maximum ripple . 47
110 Table 1 – Measurement parameters for full channel load . 22
111 Table 2 – Common RF Output Profiles for Characterization for the channel bandwidth
112 of 8 MHz . 24
113 Table 3 – Measurement parameters for full channel load . 24
114 Table 4 – Example of return loss requirements . 36
115 Table 5 – Parameters of surge voltages for different degrees of testing levels . 40
116 Table 6 – Recommendations for degree of testing levels . 40
117 Table A.3 – Intermodulation products with two signals . 42
118 Table A.4 – Intermodulation products with three signals . 43
IEC CDV 60728-103 © IEC 2025
122 INTERNATIONAL ELECTROTECHNICAL COMMISSION
123 ____________
125 CABLE NETWORKS FOR TELEVISION SIGNALS,
126 SOUND SIGNALS AND INTERACTIVE SERVICES –
128 Part 103: Active wideband equipment for cable networks with digital
129 signals only
131 FOREWORD
132 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
133 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
134 co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
135 in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
136 Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
137 preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
138 may participate in this preparatory work. International, governmental and non-governmental organizations liaising
139 with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
140 Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
141 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
142 consensus of opinion on the relevant subjects since each technical committee has representation from all
143 interested IEC National Committees.
144 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
145 Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
146 Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
147 misinterpretation by any end user.
148 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
149 transparently to the maximum extent possible in their national and regional publications. Any divergence between
150 any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
151 5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
152 assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
153 services carried out by independent certification bodies.
154 6) All users should ensure that they have the latest edition of this publication.
155 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
156 members of its technical committees and IEC National Committees for any personal injury, property damage or
157 other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
158 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
159 8) Attention is drawn to the normative references cited in this publication. Use of the referenced publications is
160 indispensable for the correct application of this publication.
161 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
162 rights. IEC shall not be held responsible for identifying any or all such patent rights.
163 International Standard IEC 60728-103 has been prepared by subcommittee technical area 5:
164 Cable networks for television signals, sound signals and interactive services, of IEC technical
165 committee Audio, video and multimedia systems and equipment.
th
166 This standard is based on the International Standard IEC 60728-3, 5 edition, but describes
167 the methods of measurement for digital modulated signals only. It also takes care for the
168 DOCSIS 4.0 requirements with additional digital modulation schemes as well as for the
169 extended frequency ranges:
170 • Up to 1794 MHz for the forward path
171 • Up to 684 MHz for the return path
IEC CDV 60728-103 © IEC 2025
173 The text of this International Standard is based on the following documents:
FDIS Report on voting
100/XX/FDIS 100/XX/RVD
175 Full information on the voting for its approval can be found in the report on voting indicated in
176 the above table.
177 The language used for the development of this International Standard is English.
178 The list of all the parts of the IEC 60728 series, published under the general title Cable networks
179 for television signals, sound signals and interactive services, can be found on the IEC website.
180 This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
181 accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
182 at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
183 described in greater detail at www.iec.ch/publications.
184 The committee has decided that the contents of this document will remain unchanged until the stability
185 date indicated on the IEC website under webstore.iec.ch in the data related to the specific document.
186 At this date, the document will be
187 • reconfirmed
188 • withdrawn
189 • replaced by a revised edition or
190 • amended
192 The National Committees are requested to note that for this document the stability date
193 is 2029.
194 THIS TEXT IS INCLUDED FOR THE INFORMATION OF THE NATIONAL COMMITTEES AND WILL BE DELETED
195 AT THE PUBLICATION STAGE.
IEC CDV 60728-103 © IEC 2025
198 INTRODUCTION
199 International Standards and other deliverables of the IEC 60728 series deal with cable networks,
200 including equipment and associated methods of measurement for headend reception,
201 processing and distribution of television and sound signals and for processing, interfacing and
202 transmitting all kinds of data signals for interactive services using all applicable transmission
203 media. These signals are typically transmitted in networks by frequency-multiplexing techniques.
204 This includes for instance:
205 • regional and local broadband cable networks,
206 • extended satellite and terrestrial television distribution systems,
207 • individual satellite and terrestrial television receiving systems,
208 and all kinds of equipment, systems and installations used in such cable networks, distribution
209 and receiving systems.
210 The extent of this standardization work is from the antennas and/or special signal source inputs
211 to the headend or other interface points to the network up to the terminal input of the customer
212 premises equipment.
213 The standardization work will consider coexistence with users of the RF spectrum in wired and
214 wireless transmission systems.
215 The standardization of any user terminals (i.e. tuners, receivers, decoders, multimedia terminals ,
216 etc.) as well as of any coaxial, balanced and optical cables and accessories thereof is excluded.
IEC CDV 60728-103 © IEC 2025
218 CABLE NETWORKS FOR TELEVISION SIGNALS,
219 SOUND SIGNALS AND INTERACTIVE SERVICES –
221 Part -103: Active wideband equipment for cable networks with digital
222 signals only
226 1 Scope
227 This part of IEC 60728 specifies the measuring methods, performance requirements and data
228 publication requirements for active wideband equipment of cable networks for television signals,
229 sound signals and interactive services with digital signals only.
230 This document
231 • applies to all amplifiers used in cable networks
232 • covers the frequency range 5 MHz to 3 000 MHz
233 NOTE The upper limit of 3 000 MHz is an example, but not a strict value.
234 • applies to one-way and two-way equipment
235 • specifies the basic methods of measurement of the operational characteristics of the active
236 equipment in order to assess the performance of this equipment
237 • identifies the performance specifications to be published by the manufacturers
238 • states the minimum performance requirements of certain parameters.
239 2 Normative references
240 The following documents are referred to in the text in such a way that some or all of their content
241 constitutes requirements of this document. For dated references, only the edition cited applies.
242 For undated references, the latest edition of the referenced document (including any
243 amendments) applies.
244 IEC 60068-1, Environmental testing – Part 1: General and guidance
245 IEC 60068-2-1, Environmental testing – Part 2-1: Tests – Tests A: Cold
246 IEC 60068-2-2, Environmental testing – Part 2-2: Tests – Tests B: Dry heat
247 IEC 60068-2-6, Environmental testing – Part 2-6: Tests – Test Fc: Vibration (sinusoidal)
248 IEC 60068-2-14, Environmental testing – Part 2-14: Tests – Test N: Change of temperature
249 IEC 60068-2-27, Environmental testing – Part 2-27: Tests – Test Ea and guidance: Shock
250 IEC 60068-2-30, Environmental testing – Part 2-30: Tests – Test dB: Damp heat, cyclic (12 h +
251 12 h cycle)
252 IEC 60068-2-31, Environmental testing – Part 2-31: Tests – Test Ec: Rough handling shocks,
253 primarily for equipment-type specimens
254 IEC 60068-2-40, Basic environmental testing procedures – Part 2-40: Tests – Test Z/AM:
255 Combined cold/low air pressure tests
IEC CDV 60728-103 © IEC 2025
256 IEC 60529, Degrees of protection provided by enclosures (IP Code)
257 IEC 60728-2, Cable networks for television signals, sound signals and interactive services –
258 Part 2: Electromagnetic compatibility for equipment
259 IEC 60728-4, Cable networks for television signals, sound signals and interactive services –
260 Part 4: Passive wideband equipment for coaxial cable networks
261 IEC 60728-5, Cable networks for television signals, sound signals and interactive services –
262 Part 5: Headend equipment
263 IEC 60728-11, Cable networks for television signals, sound signals and interactive services –
264 Part 11: Safety
265 IEC 61000-4-5, Electromagnetic compatibility (EMC) – Part 4-5: Testing and measurement
266 techniques – Surge immunity test
267 IEC 61319-1, Interconnections of satellite receiving equipment – Part 1: Europe
268 IEC 61319-2, Interconnections of satellite receiving equipment – Part 2: Japan
269 IEC 62368-1, Audio/video, information and communication technology equipment – Part 1:
270 Safety requirements
271 ANSI SCTE 279 1.8 GHz Broadband Radio Frequency Hardline Amplifiers for Cable Systems
272 3 Terms, definitions, symbols and abbreviated terms
273 For the purposes of this document, the following terms, definitions, symbols and abbreviated
274 terms apply.
275 ISO and IEC maintain terminological databases for use in standardization at the following
276 addresses:
277 • IEC Electropedia: available at http://www.electropedia.org/
278 • ISO Online browsing platform: available at http://www.iso.org/obp
279 3.1 Terms and definitions
280 3.1.1
281 amplitude frequency response
282 gain or loss of an equipment or system plotted against frequency
283 3.1.2
284 attenuation
285 ratio of the input power to the output power of an equipment or system, usually expressed in
286 decibels
287 3.1.3
288 carrier-to-noise ratio
289 difference in decibels between the vision or sound carrier level at a given point in an equipment
290 or system and the noise level at that point (measured within a bandwidth appropriate to the
291 television or radio system in use)
IEC CDV 60728-103 © IEC 2025
292 3.1.4
293 CIN
294 composite intermodulation noise
295 sum of noise and intermodulation products from digital modulated signals
296 3.1.5
297 CINR
298 composite intermodulation and noise ratio
299 ratio of the signal level and the CIN level.
300 3.1.6
301 CCN
302 carrier to composite noise in accordance with ANSI-SCTE 279.
303 The “composite noise” component is the summation of thermal noise and the intermodulation noise
304 (i.e. noise-like intermodulation distortion products) produced by the amplifier.
305 CCN in this standard is CINR.
307 3.1.7
308 crosstalk attenuation
309 ratio of the wanted signal power to the unwanted signal power, which is caused by
310 electromagnetic coupling between two leads, while equal signal powers are applied to the leads
311 Note 1 to entry: Crosstalk attenuation is usually expressed in decibels.
312 3.1.8
313 equaliser
314 device designed to compensate over a certain frequency range for the amplitude/frequency
315 distortion or phase/frequency distortion introduced by feeders or equipment
316 Note 1 to entry: This device is for the compensation of linear distortions only.
317 3.1.9
318 feeder
319 transmission path forming part of a cable network
320 Note 1 to entry: Such a path may consist of a metallic cable, optical fibre, waveguide or any combination of them.
321 By extension, the term is also applied to paths containing one or more radio links .
322 3.1.10
323 gain
324 ratio of the output power to the input power, usually expressed in decibel
325 3.1.11
326 ideal thermal noise
327 noise generated in a resistive component due to the thermal agitation of electrons
328 Note 1 to entry: The thermal power generated is given by
329 𝑃 = 4 ⋅ 𝐵 ⋅ 𝑘 ⋅ 𝑇
330 where
331 P is the noise power, in Watt;
332 B is the bandwidth, in Hertz;
−23
333 𝑘 is the Boltzmann constant = 1,38 × 10 J/K;
334 T is the absolute temperature, in Kelvin.
335 It follows that
IEC CDV 60728-103 © IEC 2025
𝑈
336 = 4 ⋅ 𝐵 ⋅ 𝑘 ⋅ 𝑇
𝑅
337 and
338 𝑈 = 4 ⋅ 𝑅 ⋅ 𝐵 ⋅ 𝑘 ⋅ 𝑇
√
339 where
340 U is the noise voltage, in Volt (e.m.f.);
341 R is the resistance, in Ω
342 In practice, it is normal for the source to be terminated with a load equal to the internal
343 resistance value, the noise voltage at the input is then U/2.
344 3.1.12
345 level
346 decibel ratio of any power P to the standard reference power P , i.e.
1 0
𝑃
347 10lg
𝑃
348 decibel ratio of any voltage U to the standard reference voltage U , i.e.
1 0
𝑈
349 20lg
𝑈
350 Note 1 to entry: The power level may be expressed in decibels relative to P = (U /R) = (1/75) pW, i.e. in dB(P ),
0 0 0
351 taking into account that the level of P corresponds to 0 dB(P ) or, as more usually, in dB(pW), taking into account
0 0
352 that the level of P corresponds to −18,75 dB(pW). The voltage level is expressed in decibels relative to 1 V (across
353 75 Ω), i.e. in dB(V).
354 3.1.13
355 MER
356 modulation error ratio
357 sum of the squares of the magnitudes of the ideal symbol vectors is divided by the sum of the
358 squares of the magnitudes of the symbol error vectors of a sequence of symbols, the result
359 being expressed as a power ratio in dB
𝑁 2 2
∑ (𝐼 +𝑄 )
𝑗=1 𝑗 𝑗
360 𝑅 = 10 lg { }   in dB
ME
𝑁 2 2
∑
(𝛿𝐼 +𝛿𝑄 )
𝑗=1 𝑗 𝑗
361 3.1.14
362 multi-switch
363 equipment used in distribution systems for signals that are received from satellites and
364 converted to a suitable IF
365 Note 1 to entry: The IF signals that are received from different polarisations, frequency bands and orbital positions
366 are input signals to the multi-switch. Subscriber feeders are connected to the multi-switch output ports. Each output
367 port is switched to one of the input ports, depending on control signals that are transmitted from the subscriber
368 equipment to the multi-switch. Besides a splitter for each input port and a switch for each output port, a multi -switch
369 can contain amplifiers to compensate for distribution or cable losses.
370 3.1.15
371 multi-switch loop through port
372 one or more ports to loop through the input signals through a multi-switch
373 Note 1 to entry: This enables larger networks with multiple multi-switches, each one installed close to a group of
374 subscribers. The multi-switches are connected in a loop through manner. The IF signals that are received by an
IEC CDV 60728-103 © IEC 2025
375 outdoor unit from different polarisations, frequency bands and orbital positions are input signals to a first multi -switch.
376 Cables connect the loop through ports of this multi-switch to the input ports of a second multi-switch and so on.
378 3.1.16
379 slope
380 difference in gain or attenuation at two specified frequencies between any two points in an
381 equipment or system
382 Note 1 to entry: The slope sign is considered
383 a) negative when the attenuation increases with frequency (cables) or the gain (amplifiers) decreases with
384 frequency,
385 b) positive when the gain (amplifiers) increases with frequency (compensating slope).
386 3.1.17
387 surge voltage
388 surge which is produced by a direct or indirect lightning stroke
389 3.2 Symbols
390 The following graphical symbols are used in the figures of this standard. These symbols are
391 either listed in IEC 60617 or based on symbols defined in IEC 60617.
IEC CDV 60728-103 © IEC 2025
Symbols Terms Symbols Terms
Ampere meter Voltmeter
based on based on
V
A
[IEC 60617-S00910 [IEC 60617-S00910

(2001-07)] (2001-07)]
Equipment under test Power meter
based on based on
EUT W
[IEC 60617-S00059 [IEC 60617-S00910
(2001-07)] (2001-07)]
Signal generator
Noise generator based on
G
G
[IEC 60617-S01230 [IEC 60617-S00899,
kT (2001-07)] IEC 60617-S01403

(2001-07)]
Variable signal generator
based on
Surge generator
G
[IEC 60617-S00081,
[IEC 60617-S01228
G
IEC 60617-S00899, IEC 60617-
(2001-07)]
S01403
(2001-09)]
Low-pass filter High-pass filter
[IEC 60617-S01248 [IEC 60617-S01247
(2001-07)] (2001-07)]
Band-pass filter Band-stop filter
[IEC 60617-S01249 [IEC 60617-S01250

(2001-07)] (2001-07)]
Spectrum analyser (electrical) Attenuator

based on A based on
P(f)
[IEC 60617-S00910 [IEC 60617-S01244
x dB
(2001-07)] (2001-07)]
Amplifier
Variable attenuator
[IEC 60617-S01245
[IEC 60617-S01239
A
(2001-07)]
(2001-07)]
Combiner
Variable resistor
based on
 [IEC 60617-S00557
[IEC 60617-S00059
(2001-07)]
(2001-07)]
Functional equipotential bonding RF choke
[IEC 60617-S01410 [IEC 60617-S00583

(2001-11)] (2001-07)]
Resistor
Capacitor
[IEC 60617-S00567
[IEC 60617-S00555
(2001-07)]
(2001-07)]
IEC CDV 60728-103 © IEC 2025
393 3.3 Abbreviated terms
AC alternating current
AM amplitude modulation
ANSI American national standards institute
BER bit error ratio
CATV community antenna television (system)
CCN carrier to composite noise
CIN composite intermodulation noise
CINR composite intermodulation and noise ratio
CW continuous wave
DC direct current
DVB-C digital video broadcasting baseline system for digital cable
television (ETSI EN 300 429)
EMC electromagnetic compatibility
EUT equipment under test
HP high pass
IF intermediate frequency
LF low frequency
LP low pass
MER modulation error ratio
OFDM orthogonal frequency-division multiplexing
QAM quadrature amplitude modulation
RF radio frequency
RMS root mean square
TCP total composite power
SCTE society of cable telecommunications engineers
TV television
394 4 Methods of measurement
395 4.1 General
396 This clause defines basic methods of measurement. Ensure that all test equipment is calibrated
397 and all connectors, leads, and terminations have an adequate quality in order to not affect the
398 test results.
399 Unless stated otherwise, all measurements shall be carried out with 0 dB plug-in attenuators
400 and equalisers. The position of variable controls used during the measurements shall be
401 published.
402 A network can be used to distribute terrestrial signals in addition to the signals received from
403 satellites. The terrestrial antennas are connected to an optional terrestrial input port of a multi-
404 switch. On each output port, the terrestrial signals are available in addition to the satellite IF
405 signals. Since the normal frequency ranges for terrestrial signals and satellite IF signals do not
406 overlap, both can be carried on the same cable.
407 For large networks with loop through connected multi-switches, two possibilities exist to carry
408 the terrestrial signals from one multi-switch to another multi-switch:
IEC CDV 60728-103 © IEC 2025
409 • to use a specialised cable for the terrestrial signal, in addition to the cables used for the
410 satellite IF signals and then, on each output port the terrestrial signal is combined with the
411 selected satellite IF signal;
412 • to combine the terrestrial signal with each satellite IF signal before the first multi -switch in
413 order to minimise the number of cables between multi-switches.
414 NOTE The signal coming from an outdoor unit for satellite reception can contain unwanted signal-components with
415 frequencies below the foreseen satellite IF frequency range. These signal-components overlap with the frequency
416 range of terrestrial signals. For example, an outdoor unit that converts the frequency band 11,7 GHz to 12,75 GHz
417 to the satellite IF frequency range can convert signals in the 10,7 GHz to 11,7 GHz band to frequencies below the
418 satellite IF frequency range. These frequencies have to be sufficiently filtered out to avoid interference with terrestrial
419 signals on the same cable.
420 For measurements on multi-switches, it is necessary that control signals be fed to the output
421 ports that are involved in the measurement. Therefore, a bias-tee has to be connected between
422 the multi-switch output port and the measurement set. The DC port of the bias-tee is connected
423 to a standard receiver that generates the required control signals. Care has to be taken that the
424 influence of the bias-tee on the measurement result is insignificant. This can be achieved by
425 including it into the calibration or using a network analyser with a built in bias-tee.
426 4.2 Linear distortion
427 4.2.1 Return loss
428 4.2.1.1 General
429 Return loss is the ratio of the reflected power to the incident power in dB. The method described
430 is applicable to the measurement of the return loss of equipment operating in the frequency
431 range 5 MHz to 3 000 MHz.
432 All input and output ports of the unit shall meet the specification under all conditions of
433 automatic and manual gain controls and with any combination of plug-in equalisers and
434 attenuators fitted.
435 4.2.1.2 Equipment required
436 A network analyser covering the frequency range of the equipment to be tested is required.
437 4.2.1.3 Measurement procedure
438 All coaxial input and output ports, other than those under test, shall be terminated in 75 Ω.
439 Ensure that there is no supply voltage on the port being measured as this could damage the
440 network analyser. If it is necessary to use a voltage blocking device, use one with a good return
441 loss (10 dB above the expected test result). Return loss shall be measured at all RF signal ports
442 of the EUT. Take into account the impact of test equipment mismatch as detailed in Annex B
443 and adjust the results accordingly.
444 4.2.1.4 Presentation of the results
445 The value of the return loss (in dB) and the frequency value (in MHz) of the measurement shall
446 be stated with the results.
447 4.2.2 Group delay variation
448 4.2.2.1 General
449 The group delay (G ) is a parameter affected by the physical length and propagation velocity in
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450 the passive and active circuits involved, where frequency-selective components, such as L-C
451 filters, e.g. diplexers, and amplifiers, are present.
IEC CDV 60728-103 © IEC 2025
452 GD is defined as the negative derivative of phase with respect to frequency, and is expressed
453 mathematically as
454 G = −(dφ/dω)
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455 The G value is measured in time units and usually expressed in nanoseconds.
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456 The group delay variation (GDV), also called group delay distortion, is the absolute value of the
457 difference between the maximum and minimum group delay within a specified frequency interval,
458 i.e. between one frequency and another in a circuit, device, or system. The group delay variation
459 (G ) is calculated using for formula (1).
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460 G = │- (dφ /dω ) │- │- (dφ /dω ) │ (1)
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1 1 2 2
461 The frequency interval is defined by the given specifications for the equipment under test or
462 can be derived from the specification of the transmission system. In cascaded systems , group
463 delay variation of each (cascaded) device accumulates and simple summation is assumed.
464 NOTE 1 Example for G derivation of cascaded systems:
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465 If the system allows a G of 120 ns, a maximum number of 6 devices, with a G of 20 ns for each device, can be
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466 cascaded.
467 NOTE 2 The term ‘group delay’ is wrongly used in some documents instead of group delay variation.
468 4.2.2.2 Equipment required
469 The following equipment is required: a vector network analyzer covering the frequency range
470 of the equipment to be tested and with features to measure transmission group delay (G ) and
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471 frequency response at the specified frequencies.
472 4.2.2.3 Measurement procedure
473 The measurement procedure is as follows:
474 a) Calibrate and align the vector network analyser in the same manner as for linear distortion
475 measurements.
476 b) Set frequency markers in frequency steps according to the specified frequency interval.
477 NOTE Examples of typical frequency intervals (bandwidths) can be found in IEC 60728-101:2016, Annex C.
478 c) The frequency interval over which the G measurement is made shall be recorded.
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479 d) Set the smoothing function in the network analyser according to the recommendations of
480 the manual of the test equipment manufacturer to get the optimum reading of the values.
481 e) Plot the GD curve versus the specified frequency interval and record it.
482 f) Read the G values for frequency 1 (ω ) and frequency 2 (ω ), calculate the difference (G )
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1 2
483 between the two values and record the result.
484 4.2.2.4 Presentation of the results
485 Present the group delay variation results (G ) and the specified frequency interval.
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486 4.3 Non-linear distortion
487 4.3.1 General
488 In a non-linear device, the expression for the output signal will, in general, have an infinity of
489 terms, each generated from one or more of the (assumed sinusoidal) terms in the input, and
490 particularly by the interaction of two or more terms.
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