BS EN 50298-1-8-2017 Communication cables Specifications for test methods Electrical test methods Attenuation《通信电缆 试验方法规范 电气试验方法 衰减》.pdf

1、BS EN 50298-1-8:2017Communication cables Specifications for test methodsPart 1-8: Electrical test methods AttenuationBSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS EN 50298-1-8:2017 BRITISH STANDARDNational forewordThis British Standard is the UK implementation o

2、f EN 50298-1-8:2017. It supersedes BS EN 50289-1-8:2001 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee EPL/46, Cables, wires and waveguides, radio frequency connectors and accessories for communication and signalling.A list of organizations represente

3、d on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2017.Published by BSI Standards Limited 2017ISBN 978 0 580 943

4、77 5 ICS 33.120.20Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 March 2017.Amendments/corrigenda issued since publicationDate Text affectedBS EN 50298-1-8:2

5、017EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 50289-1-8 March 2017 ICS 33.120.20 Supersedes EN 50289-1-8:2001 English Version Communication cables - Specifications for test methods - Part 1-8: Electrical test methods - Attenuation Cbles de communication - Spcifications des mthodes dessai P

6、artie 1-8: Mthodes dessais lectriques - Affaiblissement Kommunikationskabel - Spezifikationen fr Prfverfahren Teil 1-8: Elektrische Prfverfahren - Dmpfung This European Standard was approved by CENELEC on 2016-12-16. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which

7、 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 CEN-CENELEC Management Centre or to any CENELEC member. This

8、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 CEN-CENELEC Management Centre has the same status as the official versions. CENELE

9、C members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherland

10、s, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung CEN-CENELEC Management

11、 Centre: Avenue Marnix 17, B-1000 Brussels 2017 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members. Ref. No. EN 50289-1-8:2017 E BS EN 50298-1-8:2017EN 50298-1-8:2017 2 Contents Page European foreword 3 1 Scope . 4 2 Normative references . 4 3 Term

12、s and definitions 4 4 Test method for attenuation 5 4.1 Method A: Balun-based test method for symmetrical cables 5 4.1.1 Test equipment . 5 4.1.2 Test sample . 5 4.1.3 Calibration procedure 5 4.1.4 Measuring procedure . 5 4.2 Method B: Balun-less test method for symmetrical cables . 6 4.2.1 Test equ

13、ipment . 6 4.2.2 Test sample . 7 4.2.3 Calibration procedure 7 4.2.4 Measuring procedure . 7 4.3 Method C: Test method for coaxial cables 8 4.3.1 Test equipment . 8 4.3.2 Test sample . 9 4.3.3 Calibration procedure 9 4.3.4 Measuring procedure . 9 4.4 Method D: Open/short method 9 4.4.1 Test equipmen

14、t . 9 4.4.2 Test sample . 9 4.4.3 Calibration procedure 9 4.4.4 Measuring procedure . 10 5 Expression of test results 10 5.1 Expression . 10 5.2 Temperature correction . 11 6 Test report . 11 Bibliography . 12 BS EN 50298-1-8:2017EN 50298-1-8:2017 3 European foreword This document EN 50289-1-8:2017

15、has been prepared by CLC/TC 46X “Communication cables“. The following dates are fixed: latest date by which this document has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2017-09-16 latest date by which the national standards conflictin

16、g with this document have to be withdrawn (dow) 2019-12-16 This document supersedes EN 50289-1-8:2001. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CENELEC shall not be held responsible for identifying any or all such patent ri

17、ghts. EN 50289-1, Communication cables Specifications for test methods, is currently composed with the following parts: Part 1-1: Electrical test methods General requirements; Part 1-2: Electrical test methods DC resistance; Part 1-3: Electrical test methods Dielectric strength; Part 1-4: Electrical

18、 test methods Insulation resistance; Part 1-5: Electrical test methods Capacitance; Part 1-6: Electrical test methods Electromagnetic performance; Part 1-7: Electrical test methods Velocity of propagation; Part 1-8: Electrical test methods Attenuation; Part 1-9: Electrical test methods Unbalance att

19、enuation (longitudinal conversion loss, longitudinal conversion transfer loss); Part 1-10: Electrical test methods Crosstalk; Part 1-11: Electrical test methods Characteristic impedance, input impedance, return loss; Part 1-12: Electrical test methods Inductance; Part 1-13: Electrical test methods C

20、oupling attenuation or screening attenuation of patch cords / coaxial cable assemblies / pre-connectorised cables; Part 1-14: Electrical test methods Coupling attenuation or screening attenuation of connecting hardware; Part 1-15: Electromagnetic performance Coupling attenuation of links and channel

21、s (Laboratory conditions); Part 1-16: Electromagnetic performance Coupling attenuation of cable assemblies (Field conditions); Part 1-17: Electrical test methods Exogenous Crosstalk ExNEXT and ExFEXT. BS EN 50298-1-8:2017EN 50298-1-8:2017 4 1 Scope This European Standard details the test methods to

22、determine attenuation of finished cables used in analogue and digital communication systems. It is bound to be read in conjunction with EN 50289-1-1, which contains essential provisions for its application. 2 Normative references The following documents, in whole or in part, are normatively referenc

23、ed in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 50289-1-1, Communication cables - Specifications for test methods - Part 1

24、-1: Electrical test methods - General requirements EN 50289-1-11, Communication cables - Specifications for test methods - Part 1-11: Electrical test methods - Characteristic impedance, input impedance, return loss EN 50290-1-2, Communication cables - Part 1-2: Definitions 3 Terms and definitions Fo

25、r the purposes of this document, the terms and definitions given in EN 50289-1-1 and EN 50290-1-2 and the following apply. 3.1 cable attenuation decrease in magnitude of power of a signal that propagates along the cable 3.2 insertion loss (IL) of a network (e.g. cable or cable assembly) ratio of pow

26、er P1delivered to a specified load in a transmission system, before insertion of the given network, to the power P2delivered to the same load after insertion of the network: ( )PILP= 1210 dBlog (1) Note 1 to entry: The insertion loss of a network depends on the network itself as well as the transmis

27、sion system in which it is inserted (including the load). The insertion loss is generally expressed in decibels. Note 2 to entry: In a transmission system where the load and source impedances are equal, the insertion loss can be expressed by the scattering parameter S21.: ( ) ( )IL S=2120 dBlog (2)

28、Note 3 to entry: For a cable which is matched to the transmission system in which it is inserted, the insertion loss is equivalent to the cable attenuation. Note 4 to entry: Further information on definitions of attenuation can be found in IEC/TR 62152. BS EN 50298-1-8:2017EN 50298-1-8:2017 5 4 Test

29、 method for attenuation 4.1 Method A: Balun-based test method for symmetrical cables 4.1.1 Test equipment The test equipment consists of a vector network analyser (VNA) having at least 2 ports, and the following: S-parameter set-up (shall be capable of performing S21measurements). Baluns to convert

30、the unbalanced signal of the VNA to a balanced signal. The baluns shall have an impedance on the primary (unbalanced) side equal to the nominal impedance of the measuring devices (in general 50 ) and on the secondary (balanced) side equal to the nominal impedance of the cable under test (CUT) (e.g.

31、100 ). The baluns shall fulfil the requirements of Class A baluns as described in EN 50289-1-1. Calibration artefacts to perform the required calibration of the test equipment on the secondary side of the baluns. To perform a full 2-port calibration a short circuit, an open circuit, a reference load

32、, and a short connection cable or similar, are required. The short circuit shall have negligible inductance and the open circuit shall have negligible capacitance. The load resistor shall have a value close (within 1%) to the nominal impedance of the CUT (e.g. 100 ) and with negligible inductance an

33、d capacitance. The connection cable shall be as short as possible and well matched to the nominal impedance. Resistor termination networks (RTN) for termination of inactive pairs. The resistor termination network shall provide the differential mode and the common mode reference termination impedance

34、s. It is recommended to use resistor termination networks in accordance with Annex C of EN 50289-1-11. Baluns may be used for termination of the inactive pairs if they provide the specified differential and common mode terminations. As an alternative to a network analyser, a generator and vector vol

35、tmeter may be used. Accuracy of test set-up shall be better than 1 %. 4.1.2 Test sample The CUT shall have a minimum length as specified in the relevant sectional specification. Both ends of the CUT shall be prepared, such that when connected to the terminals of the test equipment the influence to t

36、he test result is minimized. The twisting of the pairs/quads shall be maintained. 4.1.3 Calibration procedure It is not the intent of the standard to detail the algorithms applied by a VNA to correct the measured results based on a calibration procedure but to detail the calibration procedure. Furth

37、er information may be obtained in the manuals of the VNA supplier. The calibration shall be performed on the secondary side of the baluns. A full two-port calibration is recommended using open, short, and load calibration artefacts at the terminals of the balun, and a short connection cable between

38、the two baluns for the through calibration. 4.1.4 Measuring procedure The CUT shall be connected to the terminals of the test equipment as depicted in Figure , including proper termination of the active pairs, the inactive pairs, and the screen. The connection of the CUT to the test ports shall be o

39、ptimized, such that the mismatch at the connection is minimized. For the inactive pairs, it is recommended to apply resistor termination networks as referenced in 4.1.1. BS EN 50298-1-8:2017EN 50298-1-8:2017 6 Figure 1 Attenuation measurement using baluns The scattering parameter S21shall be measure

40、d over the whole specified frequency range and at the same frequency points as for the calibration procedure. All pairs/quads of the CUT shall be measured. Under matched conditions, the attenuation a of the CUT is given by: ( ) ( )( )af S=10 2120 log dB (3) 4.2 Method B: Balun-less test method for s

41、ymmetrical cables 4.2.1 Test equipment Method B is the preferred one for balanced cables for frequencies above 1 000 MHz as it avoids the use of baluns which are often limited to 1 000 MHz. With this configuration it is possible to measure both the differential mode and the common mode attenuation o

42、f the cable. Please refer to EN 50289-1-1 for a general description of the balun-less test method and nomenclature. The test equipment consists of a multiport vector network analyser VNA having at least 4 ports, and the following: S-parameter set-up. A mathematical conversion from unbalanced to bala

43、nced, i.e. the mixed mode set-up which is often referred to as an unbalanced, modal decomposition or balun-less setup. This allows measurements of balanced devices without use of an RF balun in the signal path. With such a test set-up, all balanced and unbalanced parameters can be measured over the

44、full frequency range. Coaxial interconnection cables in accordance with the relevant clause of EN 50289-1-1 to connect the VNA, switching matrix (if used), and the test fixture. The connection cables shall have characteristic impedance equal to the nominal impedance of the VNA, and a low transfer im

45、pedance. BS EN 50298-1-8:2017EN 50298-1-8:2017 7 Coaxial calibration standards for calibration at the end of the coaxial interconnection cables (if applied). To perform a calibration at the end of the coaxial interconnection cable coaxial reference standards, so called calibration standards, i.e. a

46、short circuit, an open circuit and a reference load, are required. An alternative to the before mentioned open, short and load references is the use of an electronic multiport calibration kit (E-cal module) which is supplied by the supplier of the VNA. Calibration artefacts in accordance with the re

47、levant clause of EN 50289-1-1 for calibration at the test interface (if applied). To perform a calibration at the test interface, calibration artefacts, i.e. a short circuit, an open circuit and a reference load, are required. Resistor termination networks (RTN) for termination of inactive pairs. Th

48、e resistor termination network shall provide the differential mode and the common mode reference termination impedances. It is recommended to use resistor termination networks in accordance with Annex C of EN 50289-1-11. 4.2.2 Test sample The CUT shall have a minimum length as specified in the relev

49、ant sectional specification. Both ends of the CUT shall be prepared, such that when connected to the terminals of the test equipment the influence to the test result is minimized. The twisting of the pairs/quads shall be maintained. 4.2.3 Calibration procedure It is not the intent of the standard to detail the algorithms applied by a VNA to correct the measured results based on a calibration procedure but to detail the calibration procedure. Further infor