1、BRITISH STANDARD Connectors for electroni c equipment Tests and measurements Part 25-2: Test 25b: Attenuation (insertion loss) The European Standard EN 60512-25-2:2002 has the status ofa British Standard ICs 31.220.10 BS EN 605 12-25-21 2002 present to the responsible European committee any enquirie
2、s on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. - A list of organizations represented on this subcommittee can be obtained on request to its secretary. From 1 January 1997, al
3、l IEC publications have the number 60000 added to the old number. For instance, IEC 27-1 has been renumbered as IEC 60027-1. For a period of time during the change over fi-om one numbering system to the other, publications may contain identifiers from both systems. Cros s-r e fer en ces The British
4、Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search”faci1ity of the BSI Electronic Catalogue or of British Standards Online.
5、This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside
6、front cover, the EN title page, pages 2 to 14, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. O BSI 9 July 2002 ISBN O 580 39945 I EUROPEAN STANDARD EN 6051 2-25-2 NORME EUROPENNE EUROPISCHE NORM June 2002 ICs 31.
7、220.10 English version Connectors for electronic equipment - Tests and measurements Part 25-2: Test 25b: Attenuation (insertion loss) (IEC 6051 2-25-212002) Connecteurs pour quipements lectroniques - Essais et mesures Partie 25-2: Essai 25b: Attnuation (perte dinsertion) (CE1 6051 2-25-212002) Steck
8、verbinder fr elektronische Einrichtungen - Mess- und Prfverfahren Teil 25-2: Prfung 25b: Dmpfung (Einfgedmpfung) (IEC 60512-25-212002) This European Standard was approved by CENELEC on 2002-05-01. CENELEC members are bound to comply with the CENKENELEC Internal Regulations which stipulate the condit
9、ions 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 thr
10、ee 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 oficial versions. CENELEC members are the national electrotechnica
11、l committees of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Norm
12、alisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels O 2002 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60512-25-2:2002 E Page 2 EN 60512-25-220
13、02 Foreword The text of document 48B/1154/FDIS, future edition 1 of IEC 60512-25-2, prepared by SC 48B, Connectors, of IEC TC 48, Electromechanical components and mechanical structures for electronic equipment, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 60512-25
14、-2 on 2002-05-01. 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 - latest date by which the national standards conflicting with the EN have to be withdrawn Annexes designated “no
15、rmative“ are part of the body of the standard. Annexes designated “informative“ are given for information only. In this standard. annex A is normative and annex B is informative. (dop) 2003-02-01 (dow) 2005-05-01 En dorse ment not i ce The text of the International Standard IEC 60512-25-2:2002 was a
16、pproved by CENELEC as a European Standard without any modification. O BSI 9 July 2002 Page 3 EN 60512-25-22002 CONTENTS General 4 1 . 1 Scope 4 1.2 Definitions . 7 Test resources 4 2.1 Equipment 4 2.2 Fixture . 5 Test specimen 6 3.1 Description 6 Test procedure . 6 4.1 Fixture attenuation 6 4.2 Spec
17、imen attenuation measurement 7 4.3 Impedance analyzer (openkhort method) 8 4.4 Additional measurements 8 4.5 Time domain method . 8 Details to be specified 9 Test documentation 9 Annex A (normative) Annex B (informative) Diagrams and schematics of fixtures and equipment 10 Practical guidance 14 Figu
18、re A.l . Technical diagrams . 10 Figure A.2 . Single-ended terminations 11 Figure A.3 . Differential (balanced) terminations 12 Figure A.4 . Example of specimen in fixture for attenuation 13 O BSI 9 July 2002 Page 4 EN 60512-25-22002 CONNECTORS FOR ELECTRONIC EQUIPMENT - TESTS AND MEASUREMENTS - Par
19、t 25-2: Test 25b - Attenuation (insertion loss) 1 General 1.1 Scope and object This part of IEC 60512 is applicable to electrical connectors, sockets, cable assemblies or interconnection systems. This standard describes a frequency and a time domain method to measure attenuation/ insertion loss as a
20、 function of frequency. NOTE “Attenuation” is referenced throughout the document. Test professionals must use the appropriate term (attenuation or insertion loss) when summarizing and reporting the test measurements according to the type of specimen and transmission line being measured. 1.2 Definiti
21、ons For the purpose of this part of IEC 60512, the following definitions apply. 1.2.1 att en u at on the reduction of power during the transmission from the input to the output of the specimen, usually measured in decibels (dB) 1.2.2 insertion loss the loss of power resulting from the insertion of a
22、 connector or similar device into a transmission line, usually measured in dB 1.2.3 specimen environment impedance the impedance presented to the signal conductors by the fixture. This impedance is a result of transmission lines, termination resistors, attached receivers or signal sources, and fixtu
23、re parasitics 2 Test resources 2.1 Equipment 2.1.1 Frequency domain A network analyzer is preferred. When a greater dynamic range is desired, a signal generator and spectrum analyzer or vector network analyser (for measurement with full 2-port calibration) may alternatively be used. If necessary, ad
24、ditional equipment increasing the measurement sensitivity (e.g. broadband output amplifiers or low-noise pre-amplifiers) may be used. For differential measurements, a multiport network analyzer with appropriate software or baluns may be used. O BSI 9 July 2002 Page 5 EN 60512-25-22002 2.1.2 Time dom
25、ain A time domain reflectometer (TDR), triggered impulse generator and appropriate fast Fourier transform (FFT) software are preferred. 2.2 Fixture Unless otherwise specified in the reference document, the specimen environment impedance shall match the impedance of the test equipment. Typically, thi
26、s will be 50 R for single-ended measurements and 1 O0 R for differential measurements. 2.2.1 Specimen conductor assignments For each measurement, the line to be measured shall be fixed as indicated in the referencing document. The far end (destination) and the near end (driven) of the line shall be
27、terminated in the specimen environment impedance specified using one of the methods in figures A.2 or A.3. In the special case where the drive signal is differential and not balanced, the common mode energy shall be terminated. Signal lines adjacent to these should likewise be terminated, if possibl
28、e. NOTE Electrically long adjacent signal lines may resonate adding error to the results Unless otherwise specified, a 1 :I signal-to-ground ratio (2:l if differential measurements are performed) shall be used with each end having all grounds commoned. (For an example, see figure A.4). 2.2.2 Specime
29、n fixture and signal line terminations for specimen environment impedance Care should be taken to minimize the reactances of the resistive terminations over the range of test frequencies. NOTE The fixture geometry and materials may impact the measurements due to the fixture parasitics. Usually, the
30、products intended use dictates the most meaningful way to fix it. 2.2.3 Insertion technique The fixture shall be designed to allow the measurement of attenuation with and without the specimen, see figure A.la. If baluns are used for a measurement, or minimum loss pads used for impedance matching, th
31、ese are included in the fixture. Figures A.2 and A.3 show typical configurations with minimum loss pads. 2.2.4 Reference fixture technique In this technique, a separate fixture that combines both near end and far end is used for the fixture attenuation measurement; see figure A.lb. This fixture shal
32、l be a duplicate of the specimen fixture, only without the specimen. Traces, if used, shall include fixture connectors, vias, bends and corners. If baluns are used for a differential measurement, or minimum loss pads used for impedance matching, these are included in the fixture. Figures A.2 and A.3
33、 show typical configurations with minimum loss pads. O BSI 9 July 2002 Page 6 EN 60512-25-22002 3 Test specimen 3.1 Description For this test procedure, the test specimen shall be as follows: 3.1.1 Separable connectors A mated connector pair. 3.1.2 Cable assembly Assembled connectors and cables, and
34、 mating connectors. 3.1.3 Sockets A socket and test device or a socket and pluggable header adapter 4 Test procedure Unless otherwise specified, all measurement results shall contain a minimum of 200 frequency points. Each fixture measurement and its associated specimen attenuation measurement shall
35、 be taken at the same frequencies. Generate a magnitude versus frequency plot; 1 dB per division vertical scale and log frequency sweep are recommended. When applicable, single frequency results shall be tabulated, as specified in the reference document. Place the specimen at a minimum of 5 cm from
36、any objects that would affect measured results. NOTE Test professionals should be aware of the limitations of any math operation(s) performed by an instrument (e.g. normalization or software filtering). 4.1 Fixture attenuation Fixture attenuation shall be measured separately so that it can be remove
37、d from and compared to the specimen measurement. If the reference document specifies precisely the fixture so that its attenuation contribution is known, then the fixture attenuation measurement is optional. 4.1.1 Calibration 4.1.1.1 When using a network analyzer, as a minimum, a “through“ calibrati
38、on at the reference plane (including analyzer cables, but not the specimen fixture) shall be performed. Where possible, a 12 term calibration is recommended. 4.1.1.2 When using a spectrum analyzer and generator, take a reference measurement following the same procedure. The generator output shall be
39、 kept the same for both fixture and specimen-with-fixture attenuation measurements made later. NOTE a) The specimen attenuation is not greater than the fixture attenuation b) The fixture electrical length is greater than 1/8 wavelength at the highest test frequency, unless special precautions are ta
40、ken to ensure good impedance matching throughout the measurement path. This can be confirmed by sweeping across a wide frequency range and observing if there are nulls due to moding, fixture or balun resonances, etc. Results may be inaccurate when: O BSI 9 July 2002 Page 7 EN 60512-25-22002 4.1.2 In
41、sertion technique 4.1.2.1 Assemble the fixture so that the near end is connected to the far end without the specimen in between; see figure A.la. Connect the network analyzer ports, or the signal generator and spectrum analyzer, to the appropriate locations of the driven line fixture. 4.1.2.2 When u
42、sing a network analyzer, measure the fixture attenuation (S21). When using a spectrum analyzer, measure the power from the generator through the fixture. Then, divide the magnitude of this signal by that of the reference measurement performed in 4.1.1.2 at each frequency (subtract in dB). This is th
43、e fixture attenuation. 4.1.3 Reference fixture technique 4.1.3.1 Construct a reference fixture that duplicates the specimen fixture, but without the specimen. Include both near and far ends; see figure A.lb. Connect the network analyzer ports, or the signal generator and spectrum analyzer, to the ap
44、propriate locations of the driven line fixture. 4.1.3.2 When using a network analyzer, measure the fixture attenuation (S21). 4.1.3.3 When using a spectrum analyzer, measure the power from the generator through the fixture. Then, divide the magnitude of this signal by that of the reference measureme
45、nt performed in 4.1 .I .2 at each frequency (subtract in dB). This is the fixture attenuation. 4.2 4.2.1 Add specimen to fixture. Specimen attenuation meas u remen t 4.2.2 Network analyzer 4.2.2.1 the analyzer to the far end of the fixture. Connect the analyzer drive port to the near end of the fixt
46、ure and the receiver port of 4.2.2.2 Measure the specimen-with-fixture attenuation in dB 4.2.3 Spectrum analyzer 4.2.3.1 input to the far end of the fixture. Connect the generator output port to the near end of the fixture and the analyzer 4.2.3.2 Measure the signal power (typically in dBm). Divide
47、the magnitude of this signal by that of the reference measurement, see 4.1 .I .2, at each frequency (subtract in dBm). Record specimen-with-fixture results in dB. 4.2.4 Divide the specimen-with-fixture attenuation by the fixture attenuation (subtract in dB) and plot. This is the specimen attenuation
48、. Record single frequency results and tabulate, if requested. O BSI 9 July 2002 Page 8 EN 60512-25-22002 4.3 Impedance analyzer (open/short method) 4.3.1 Calibrate the instrument according to the manufacturers instructions. This is typically done using short and open-circuit standards connected one
49、at a time at the specimen measurement location of the fixture. 4.3.2 Connect the specimen to the fixture with the far end of the specimen open-circuited, and measure the magnitude and phase of the specimen plus fixture impedance. 4.3.3 Short-circuit the far end of the specimen, and measure the magnitude and phase of the specimen plus fixture impedance. 4.3.4 Calculate the attenuation of the specimen plus fixture using the following equations: P = ( I zOp I I zST I)” and + = (ST - cop) 12 where Zop and eo, are the open-circuit impedance and phase, respectively, and ZS
