BS EN 60510-2-5-1996 Methods of measurement for radio equipment used in satellite earth stations - Measurements for sub-systems - Frequency modulators《卫星地面站用无线电设备测量方法 第2部分 分系统测量 第5.pdf

1、BRITISH STANDARD BS EN 60510-2-5:1996 IEC 510-2-5: 1992 Methods of Measurement for radio equipment used in satellite earth stations Part 2: Measurements for sub-systems Section 2.5 Frequency modulators The European Standard EN60510-2-5:1994 has the status of a British Standard ICS 33.060.30BSEN60510

2、-2-5:1996 This British Standard, having been prepared under the directionof the ElectrotechnicalSector Board, was published under the authorityof the Standards Boardand comes into effect on 15July1996 BSI 01-2000 The following BSI references relate to the work on this standard: Committee reference E

3、PL/12/5 Draft announced in BSI News, Update September1995 ISBN 0 580 26113 1 Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical Committee EPL/12, Radio communication, to Subcommittee EPL/12/5, Radio communication systems, upon which t

4、he following bodies were represented: British Broadcasting Corporation British Radio and Electronic Equipment Manufacturers Association British Telecommunications plc ERA Technology Ltd. Institution of Electrical Engineers Radio, Electrical and Television Retailers Association Radiocommunications Ag

5、ency Amendments issued since publication Amd. No. Date CommentsBSEN60510-2-5:1996 BSI 01-2000 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 Text of EN 60510-2-5 3 List of references Inside back coverBSEN60510-2-5:1996 ii BSI 01-2000 National foreword This

6、Section of BS EN60510 has been prepared by Subcommittee EPL/12/5 and is the English language version of EN60510-2-5:1994 Methods of measurement for radio equipment used in satellite earth stations Part 2: Measurement for sub-systems Section 5: Frequency modulators, published by the European Committe

7、e for Electrotechnical Standardization (CENELEC). It is identical with IEC510-2-5:1992, published by the International Electrotechnical Commission (IEC). This standard is published in three Parts. The other Parts are: Part 1: Methods common to sub-systems and combinations of sub-systems; Part 3: Met

8、hods of measurement for combinations of sub-systems. References in the text to IEC page numbers should be ignored. For ease of reproduction, some of the figures also include the French text. A British Standard does not purport to include all the necessary provisions of a contract. Users of British S

9、tandards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references Publication referred to Corresponding British Standard BS EN 60510 Methods of measurement for radio equipment used in satellite earth

10、 stations EN 60510-2-6:1994 (IEC 510-2-6:1992) Part 2 Measurements for sub-systems Section 2.6:1996 Frequency demodulators EN 60510-3-4:1994 (IEC 510-3-4:1992) Part 3 Methods of measurement on combinations of sub-systems Section 4:1996 Measurements for frequency division multiplex (f.d.m.) transmiss

11、ion Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, the EN title page, pages2 to12, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendmen

12、t table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN60510-2-5 June1994 UDC621.389.6:629.783:621.317.08 Descriptors: Radiocommunications, telecommunications, satellite broadcasting, radio equipment, earth stations, characteristics, measurements, frequency modulation,

13、 modulators English version Methods of measurement for radio equipment used in satellite earth stations Part 2: Measurements for sub-systems Section 5: Frequency modulators (IEC 510-2-5:1992) Mthodes de mesure pour les quipements radiolctriques utiliss dans les stations terriennes de tlcommunication

14、 par satellites Partie 2: Mesures sur les sous-ensembles Section cinq: Modulateurs de frquence (CEI 510-2-5:1992) Meverfahren fr Funkgert in Satelliten-Erdfunkstellen Teil 2: Messungen an Untersystemen Hauptabschnitt Fnf: Frequenzmodulatoren (IEC 510-2-5:1992) This European Standard was approved by

15、CENELEC on1994-03-08. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which 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 stan

16、dards may be obtained on application to the Central Secretariat or to any CENELEC member. This 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 not

17、ified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland a

18、nd UnitedKingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1994 Copyright reserved to CENELEC members Ref. No. EN60510-2-5:

19、1994 EEN60510-2-5:1994 BSI 01-2000 2 Foreword The CENELEC questionnaire procedure, performed for finding out whether or not the International Standard IEC510-2-5:1992 could be accepted without textual changes, has shown that no common modifications were necessary for the acceptance as European Stand

20、ard. The reference document was submitted to the CENELEC members for formal vote and was approved by CENELEC as EN60510-2-5 on8March1994. The following dates were fixed: Annexes designated “normative” are part of the body of the standard. In this standard,Annex ZA is normative. Contents Page Forewor

21、d 2 1 Scope 3 2 Definition 3 3 General 3 4 I.F.output characteristics 3 5 Baseband input impedance and return loss 4 6 Deviation sensitivity 4 7 Sense of modulation 5 8 Differential gain/non-linearity and differential phase/group delay 5 9 Unwanted amplitude modulation 6 10 Baseband amplitude/freque

22、ncy characteristic 7 11 Frequency division multiplex (f.d.m.) telephony measurements 8 12 Television measurements 8 13 Carrier-energy dispersal sub-system 8 14 References 8 Annex ZA (normative) Other international publications quoted in this standard with the references of the relevant European publ

23、ications 11 Figure 1 Arrangement of a typical satellite earth station frequency modulator sub-system 9 Figure 2 Simplified arrangement for measuring the differential gain, differential phase and i.f. amplitude/frequency characteristic of a modulator 10 latest date of publication of an identical nati

24、onal standard (dop) 1995-03-15 latest date of withdrawal of conflicting national standards (dow) 1995-03-15EN60510-2-5:1994 BSI 01-2000 3 1 Scope Methods are given in this section for the measurement of the electrical characteristics of frequency modulators. Furthermore, where possible, only measure

25、ments involving the basic modulator are considered, that is excluding the baseband section comprising the pre-emphasis network and the networks associated with sound sub-carrier signals, pilot signals and auxiliary signals. Methods of measurement for frequency demodulators are given in section6 of p

26、art2 of this publication. Measurements between baseband terminals of modulator/demodulator assemblies are covered by various sections of part3 of this publication. 2 Definition For the purpose of this standard, a frequency modulator is a sub-system which, by analogue means, modulates an intermediate

27、 frequency (i.f.) carrier by a baseband signal: this may be a multi-channel f.d.m, telephony signal or television signal with associated sound sub-carrier signals, pilot signals and auxiliary signals. Such baseband signals are normally analogue but digital signals are not excluded. However the metho

28、ds of measurement described in this section are intended for assessing the performance of the modulator when analogue signals are transmitted. A modulator sub-system usually comprises the following three main sections: a baseband section; a baseband to i.f.section (modulator); an i.f.section. 3 Gene

29、ral A block diagram for a typical modulator sub-system is shown inFigure 1. The characteristics to be measured can be divided into three principal categories: non-transfer characteristics; baseband to i.f.characteristics; certain baseband-to-baseband transmission characteristics in conjunction with

30、a measurement demodulator. The first category concerns measurements at the baseband port only or at the i.f.port only including frequency and spurious/harmonic signal measurements at the i.f.output. These measurements are described elsewhere in this publication. The second category of measurements f

31、orms an essential part of this section because of the nature of the device under test transfer from baseband toi.f. The third category of measurements includes those to be carried out on a complete modulator/demodulator (modem) assembly except that the actual or system demodulator is replaced by a m

32、easurement demodulator. It is very important to know the separate contribution of a modulator to the total permitted tolerances of performance characteristics because in an operational situation, modulators of one design or manufacturer may have to work with demodulators of another design or manufac

33、turer. Compensation effects between modulator and demodulator are therefore undesirable and each modulator should fulfill the prescribed specification in association with a measurement demodulator. This procedure requires the measurement demodulator to have a better performance than that specified f

34、or the modulator under test. 4 I.F.output characteristics 4.1 Return loss See part1, section3 of this publication: Measurements in the i.f.range. The measurement shall be made without the modulator output signal being present. This can be achieved, for example, by disabling the oscillator within the

35、 modulator. 4.2 Level See part1, section3 of this publication: Measurements in the i.f.range. 4.3 Carrier frequency See part1, section3 of this publication: Measurements in the i.f.range (Amendment1). 4.4 I.F.spurious and/or harmonic signals 4.4.1 Method of measurement The i.f.output of the modulato

36、r shall be checked by means of a suitable spectrum analyzer or selective level-meter to verify that the level of any i.f.spurious and/or harmonic signals is within specified limits. It shall be noted that the measurement of i.f.spurious and harmonic signals shall be made without modulation and with

37、the energy-dispersal generator disabled.EN60510-2-5:1994 4 BSI 01-2000 4.4.2 Presentation of results The results should be presented preferably as a photograph, plot or X-Y record of the calibrated spectrum analyzer display. Alternatively, the more significant spurious and/or harmonic levels may be

38、expressed in decibels relative to the level of the wanted signal. 4.4.3 Details to be specified The following items should be included as required in the detailed equipment specification: a) permitted maximum level of spurious signals in decibels relative to the wanted signal; b) permitted maximum l

39、evel of harmonics in decibels relative to the wanted signal; c) the frequency range over which measurements are required; d) the level of the wanted signals. 5 Baseband input impedance and return loss See part1, section4 of this publication: Measurements in the baseband. 6 Deviation sensitivity 6.1

40、Definition and general considerations The deviation sensitivity (S m ) of a modulator for a sinusoidal signal of a given frequency is expressed as the ratio of the frequency deviation (f) to the value of the baseband input voltage (V b ): V band f are both expressed either in peak values or in r.m.s

41、.values. The deviation sensitivity is usually a function of the baseband frequency due to the effect of the pre-emphasis network 1 1)2 1) . When it is possible to gain access to the baseband input point (seeFigure 1) after the pre-emphasis network, the measured deviation sensitivity of the modulator

42、 is independent of the baseband frequency used. 6.2 Method of measurement The method of measurement is known as the “Bessel zero” method which is based on the fact that, in the case of sinusoidal modulation, the carrier frequency spectral line first disappears at a modulation index (m f ) as follows

43、: where f is the peak frequency deviation and f is the modulating frequency. The “zero”, i.e.the point where the i.f.carrier first disappears, is observed on the spectrum analyzer, but a perfect zero may not be obtained due to residual harmonic distortion of the baseband signal generator. However, a

44、 decrease in carrier level of30 dB or more is regarded as adequate. Since there are many values of the modulation index at which a carrier-zero may be obtained, the best way of ensuring that the first zero is used is by increasing the modulating voltage smoothly from zero to the point where the carr

45、ier disappears for the first time. The measurement procedure is as follows: a) the baseband generator is set to the required frequency at which the deviation sensitivity is to be measured; b) the output level of the generator is set to zero and then smoothly increased until the i.f.carrier on the sp

46、ectrum analyzer first disappears; c) the r.m.s.voltage (V b ) at the baseband input of the modulator is measured; d) the modulator deviation sensitivity (S m ) at modulation frequency f is then calculated from equation 63: NOTEAs a modulation index of2,40483 corresponds to an occupied i.f.bandwidth

47、which increases linearly with modulation frequency, the use of this method is restricted to modulation frequencies which do not cause the modulated signal spectrum to exceed the system bandwidth. An alternative method is to employ a calibrated measurement demodulator. 6.3 Presentation of results The

48、 results should be presented as in the following examples: “The deviation sensitivity (S m ) was (MHz/V)” or “At a baseband input level of.dBm, the r.m.s.frequency deviation waskHz”. 6.4 Details to be specified The following items should be included as required in the detailed equipment specificatio

49、n: a) the method of measurement (see6.2 or note); b) the frequency of the baseband input signal; c) the frequency deviation of the i.f.output signal; d) the required deviation sensitivity or output deviation at the specified input level; (61) 1) The figures in square brackets indicate the references given in clause14. (62) S m f V b - = MHz/V () m f f f -2,404 83 = = (63) S m 2,404 83 f 2V b - = MHz/VEN60510-2-5:1994 BSI 01-2000 5 e) the baseband connection point (i.e.befor