1、BRITISH STANDARD BS EN 60835-1-2:1995 BS 7573-1.2: 1993 IEC 835-1-2: 1992 Incorporating Amendment No. 1 to BS 7573-1.2:1993 (renumbers BS as BSEN 60835-1-2: 1995) and Amendment No. 1 to BS EN 60835-1-2:1995 Methods of measurement for equipment used in digital microwave radio transmission systems Par
2、t 1: Measurements common to terrestrial radio-relay systems and satellite earth stations Section 1.2 Basic characteristics The European Standard EN 60835-1-2:1993 together with its amendment A1:1995, has the status of a British Standard ICS 33.060.30BSEN60835-1-2:1995 This British Standard, having b
3、een prepared under the directionof the Electronic Equipment Standards Policy Committee, was published underthe authority of the Standards Board and comes intoeffect on 15 April 1993 BSI 03-2000 The following BSI references relate to the work on this standard: Committee reference EEL/25 Drafts for co
4、mment 89/24855 DC 90/33008 DC ISBN 0 580 21732 9 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Electronic Equipment Standards Policy Committee (EEL/-) to Technical Committee EEL/25, upon which the following bodies were represented: Bri
5、tish Broadcasting Corporation British Radio and Electronic Equipment Manufacturers Association British Telecommunications plc Institution of Electrical Engineers Radio, Electrical and Television Retailers Association Radiocommunications Agency The following body was also represented in the drafting
6、of the standard, through subcommittees and panels: ERA Technology Ltd. Amendments issued since publication Amd. No. Date Comments 8678 July 1995 Renumbers BS as BS EN 60835-1-2:1995 9600 September 1997 Indicated by a sideline in the marginBSEN60835-1-2:1995 BSI 03-2000 i Contents Page Committees res
7、ponsible Inside front cover National foreword ii Foreword 2 Introduction 3 1 Scope 3 2 Carrier frequency 3 3 Spectrum 4 4 Impedance (admittance) 6 5 Level (voltage/power level, gain) 7 6 Noise temperature and noise figure 10 Annex A (informative) Bibliography 20 Figure 1 Arrangement for measuring fr
8、equency 16 Figure 2 Arrangement for spectrum measurement 16 Figure 3 Typical arrangement for measuring intermodulation products 16 Figure 4 Typical arrangement for measuring return loss using a reflectometer 17 Figure 5 Arrangement for return loss measurements using the bridge method 17 Figure 6 Typ
9、ical arrangement for measuring insertion gain or loss 18 Figure 7 Arrangement for the measurement of noise figure using the Y-factor method 18 Figure 8 Arrangement for the measurement of noise figure using the 3 dB loss method with a variable level noise source 18 Figure 9 Arrangement for the measur
10、ement of noise figure using the 3 dB loss method with a fixed level noise source 19 Figure 10 Arrangement for the measurement of noise figure using the c.w. method 19BSEN60835-1-2:1995 ii BSI 03-2000 National foreword This Section of BS EN 60835 has been prepared by Technical Committee EPL/102 (form
11、erly EEL/25), and is the English language version of EN60835-1-2:1993 Methods of measurement for equipment used in digital microwave radio transmission systems Part1: Measurements common to terrestrial radio-relay systems and satellite earth stations Section 2: Basic characteristics, including amend
12、ment A1:1995, published by the European Committee for Electrotechnical Standardization (CENELEC). It is identical with IEC835-1-2:1992, including amendment No.1:1995, published by the International Electrotechnical Committee (IEC). A British Standard does not purport to include all the necessary pro
13、visions of a contract. Users of British Standards are responsible for their 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 front cover, pages i and ii, theEN title pa
14、ge, pages 2 to 20 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 60835-1-2 August 1993 + A1 March 1995 UDC 621
15、.396.6:629.783:621.317.08 Descriptors: Radiocommunications, telecommunications, satellite broadcasting, communication equipment, earth stations, radio-relay systems, microwave frequencies, tests, characteristics, measurements English version Methods of measurement for equipment used in digital micro
16、wave radio transmission systems Part1: Measurements common to terrestrial radio-relay systems and satellite earth stations Section 2: Basic characteristics (includes amendment A1:1995) (IEC 835-1-2:1992 + A1:1995) Mthodes de mesure applicables au matriel utilis pour les systmes de transmission numri
17、que en hyperfrquence Partie 1: Mesures communes aux faisceaux hertziens terrestres et aux stations terriennes de tlcommunications par satellite Section 2: Caractristiques de base (inclut lamendement A1:1995) (CEI835-1-2:1992 + A1:1995) Meverfahren fr Gerte in digitalen Mikrowellen-Funkbertragungssys
18、temen Teil 1: Messungen an terrestrischen Richtfunksystemen und Satelliten-Erdfunkstellen Hauptabschnitt 2: Grundlegende Eigenschaften (enthlt nderung A1:1995) (IEC835-1-2:1992 + A1:1995) This European Standard was approved by CENELEC on 1993-07-06. CENELEC members are bound to comply with the CEN/C
19、ENELEC 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 standards may be obtained on application to the Central Secretariat or to an
20、y 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 notified to the Central Secretariat has the same status as the official ver
21、sions. 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 and UnitedKingdom. CENELEC European Committee for Electrotechnical Standa
22、rdization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1993 Copyright reserved to CENELEC members Ref. No. EN 60835-1-2:1993 + A1:1995 EEN60835-1-2:1993 BSI 03-2000 2 Foreword The CENELEC que
23、stionnaire procedure, performed for finding out whether or not the InternationalStandard IEC835-1-2:1992 could be accepted without textural changes, has shown that no common modifications where necessary for the acceptance as a European Standard. The reference document was submitted to theCENELEC me
24、mbers for formal vote and was approved by CENELEC as EN60835-1-2 on 6 July1993. The following dates were fixed: Foreword to amendment A1 The text of document 12E(CO)164, future amendment 1 to IEC835-1-2:1992, prepared bySC12E, Radio-relay and satellite communications systems, of IECTC12, Radiocommun
25、ications, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as amendment A1 to EN60835-1-2:1993 on 1995-03-06. The following dates were fixed: latest date of publication ofan identical national standard (dop) 1994-08-01 latest date of withdrawal ofconflicting national standa
26、rds (dow) 1994-08-01 latest date by which the amendment has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 1996-03-01 latest date by which the national standards conflicting with the amendment have to be withdrawn (dow) 1996-03-01EN60835-
27、1-2:1993 BSI 03-2000 3 Introduction Modern test sets often combine a number of different measurement functions under the control of a microprocessor. In this way generally more than one parameter is checked and analysed step-by-step in accordance with specific software programmes. The results of the
28、 measurements are printed or plotted automatically and the programme description and tolerance analysis form part of the presentation of results. An example of such specialized equipment is a network analyser which combines two and four-port measurement facilities in one microprocessor-controlled un
29、it. 1 Scope This section of IEC 835-1 deals with the measurement of basic characteristics common to terrestrial radio-relay systems and satellite earth stations. These basic characteristics apply to all of the frequency ranges employed in the radio systems,i.e: radio frequency; intermediate frequenc
30、y; baseband (e.g.clock frequency of the digital baseband signal). The method of measurement for each parameter (e.g.return loss) is presented, wherever possible, asa single clause which is applicable to any of the above frequency ranges. Where exceptions occur, they will be given in the relevant cla
31、uses. 2 Carrier frequency 2.1 Definition and general consideration The carrier frequency is that frequency in the r.f. signal spectrum which is modulated by the information, or baseband, signal. The carrier frequency is normally measured without modulation. If energy dispersal is employed, it should
32、 be rendered inoperative, if possible, before making measurements. 2.2 Methods of measurement The arrangement for measuring frequency using a counter or digital frequency-meter is shown in Figure 1. The band-pass filter is required only if spurious signals are present. The amplifier and/or attenuato
33、r are required only if the input range of the frequency-meter does not cover the range of levels concerned. Both the equipment under test and the test equipment itself should be allowed to attain thermal stability before making any measurements. The digital frequency-meter indications are then read
34、during an interval of, for example, one second, depending upon the integrating time of the instrument used. Alternatively, a recorder may be used to record the indications of the digital frequency-meter for a number of counts. The number of counts will depend upon whether noise is present or not, an
35、d whether this modulates the signal or is superimposed uponit. Generally, the analysis of a statistical series averaged over several measuring intervals will provide evidence of the repeatability of the results. NOTEThe above method may also be used when the r.f. carrier is modulated by a zero mean
36、baseband signal, provided that the digital frequency-meter does not introduce errors which depend upon the modulating signal. The averaging interval of the digital frequency-meter should exceed100cycles of the modulating signal. Alternatively, e.g.when performing frequency measurements on baseband s
37、ignals, where a long time is required (10 s or more), several counter readings with a short averaging time can be taken and the average of these readings calculated. There are also other methods applicable for carrier frequency measurement with modulation. For example, the substitution or interferen
38、ce method using a spectrum analyser as an indicator in conjunction with a synthesizer as a reference frequency source. 2.3 Presentation of results The readings of the digital frequency-meter should be recorded manually or automatically as a function of time. The integrating time and the accuracy of
39、the digital frequency-meter should be stated. When several counter readings are taken they should be tabulated, together with the calculated average value.EN60835-1-2:1993 4 BSI 03-2000 The measured accuracy can be expressed as an absolute value, e.g.50kHz, or as a fractional value, e.g.one part in1
40、0 5 . The nominal carrier frequency should also be stated. 2.4 Details to be specified The following items should be included, as required, in the detailed equipment specification: a) nominal value of frequency and required accuracy; b) the part of the equipment to be measured and the port at which
41、the measurement is to be made; c) permitted frequency tolerance. 3 Spectrum It is necessary to evaluate the spectrum which is to be transmitted by the radio-relay or satellite earth station in terms of wanted or unwanted signals. Wanted signals within the necessary bandwidth are treated under “signa
42、l spectrum”, and unwanted signals which appear outside the necessary bandwidth are treated under “spurious emissions”. 3.1 Signal spectrum 3.1.1 Definitions and general considerations In accordance with reference 1 the spectrum of a modulated signal is defined by the following characteristics: neces
43、sary bandwidth; occupied bandwidth; out-of-band signal; unwanted spectrum components. The necessary bandwidth is a theoretical value which ensures that the information will be transmitted with the required quality, whereas the occupied bandwidth is a measurable value within which a specified percent
44、age of the total power of a given signal should lie (e.g.99%). The out-of-band signal is that part of the signal which is outside the necessary bandwidth and results from the modulation process and/or caused by spectral restoration or spectral spreading. Unwanted spectrum components within the neces
45、sary bandwidth are also measured. NOTEUnwanted components with an inadmissibly high level in the transmitted signal usually adversely affect the error ratio. These components therefore have a different significance in digital systems than in analogue systems. 3.1.2 Methods of measurement A suitable
46、measuring arrangement is shown inFigure 2. To measure the spectrum of the modulated signal, a random bit sequence modulation may be applied. Thisbit sequence is usually generated by a pseudo-random generator (e.g.a sequence of2 23 1bits for140Mbit/s systems). The resolution bandwidth of the analyser
47、 should be greater than the bit rate of the pseudo-random bit sequence by a factor of50 to100 e.g.for a bit rate of34Mbit/s and a sequence of2 151bits, the resolution bandwidth is (50:100) 34 10 6 /(2 15 1), approximately50:100kHz. To measure the level of the unwanted components within the necessary
48、 bandwidth it is necessary to operate the equipment under test without modulation. 3.2 Spectrum of spurious components 3.2.1 Definition and general considerations According to the Radio Regulations, a spurious emission is an emission on a frequency or frequencies which are outside the necessary band
49、width and the level of which may be reduced without affecting the corresponding transmission of information. Spurious emissions include harmonic emissions, parasitic emissions, intermodulation products and frequency conversion products, but exclude out-of-band emissions. Unwanted signal components may be divided into two categories: i) Spurious components excluding intermodulation products but including: harmonic signals; parasitic signals; frequency conversion products.EN60835-1-2:1993 BSI
