1、BRITISH STANDARD BS EN 61843:1997 IEC 61843:1997 Measuring method for the level of intermodulation products generated in a gyromagnetic device The European Standard EN 61843:1997 has the status of a British Standard ICS 29.100.10BSEN61843:1997 This British Standard, having been prepared under thedir
2、ectionof the Electrotechnical Sector Board,waspublished under theauthorityof the StandardsBoardand comes into effect on 15 October 1997 BSI 03-2000 ISBN 0 580 28423 9 National foreword This British Standard is the English language version of EN 61843:1997. It is identical with IEC 61843:1997. The UK
3、 participation in its preparation was entrusted to Technical Committee EPL/51, Transformers, inductors, magnetic components and ferrite materials, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the i
4、nterpretation, 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 committee can be obtained on request to its secretary. From 1 January 1997, all IEC publicati
5、ons 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 from one numbering system to the other, publications may contain identifiers from both systems. Cross-references Attention is drawn to the fact th
6、at CEN and CENELEC Standards normally include an annex which lists normative references to international publications with their corresponding European publications. The British Standards which implement these international or European publications may be found in the BSI Standards Catalogue under t
7、he section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct appli
8、cation. 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 page, pages 2 to 5 and a back cover. This standard has been updated (see copyright date) an
9、d may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSEN61843:1997 BSI 03-2000 i Contents Page National foreword Inside front cover Foreword 2 Text of EN 61843 3ii blankEUROPEAN STA
10、NDARD NORME EUROPENNE EUROPISCHE NORM EN 61843 August 1997 ICS 29.100.10 Descriptors: Gyromagnetic device, level of intermodulation products, principle of measurement, measuring arrangement, measuring procedure, expression of results English version Measuring method for the level of intermodulation
11、products generated in a gyromagnetic device (IEC 61843:1997) Mthode de mesure du niveau des produitsdintermodulation gnrs dans un dispositif gyromagntique (CEI 61843:1997) Meverfahren zur Bestimmung des Pegels von Intermodulationsprodukten, erzeugt in einem gyromagnetischen Bauelement (IEC 61843:199
12、7 This European Standard was approved by CENELEC on 1997-07-01. 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 bibliographica
13、l references concerning such national standards 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 CE
14、NELEC member into its own language and notified 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, Norw
15、ay, Portugal, Spain, Sweden, Switzerland and United Kingdom. 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 1997 CENELEC All righ
16、ts of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61843:1997 EEN61843:1997 BSI 03-2000 2 Foreword The text of document 51/440/FDIS, future edition 1 of IEC 61843, prepared by IEC TC 51, Magnetic components and ferrite materials, was submitted to the
17、IEC-CENELEC parallel vote and was approved by CENELEC as EN 61843 on 1997-07-01. The following dates were fixed: Endorsement notice The text of the International Standard IEC61843:1997 was approved by CENELEC as a European Standard without any modification. Contents Page Foreword 2 1 Scope and objec
18、t 3 2 Principle of measurement 3 3 Measuring arrangement 3 3.1 Generators (1 and 2) 3 3.2 Directional couplers 3 3.3 Frequency meters (1 and 2) 3 3.4 Power meters 3 3.5 Band-pass filters 4 3.6 Low-pass filter 4 3.7 Variable attenuators 4 3.8 Power combiner 4 3.9 Receiver 4 4 Measuring procedure 4 5
19、Expression of results 4 Figure1Measuring arrangement for intermodulation products 5 Table1Recommended conditions for generators 3 latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 1998-04-01 latest date by whi
20、ch the national standards conflicting with the EN have to be withdrawn (dow) 1998-04-01EN61843:1997 BSI 03-2000 3 1 Scope and object This International Standard describes the measuring method for the level of intermodulation products generated in a gyromagnetic device. When two or more signals of di
21、fferent frequencies enter into a device and/or equipment having non-linear characteristics (contact point, flexible waveguide, ferrite device, etc.), harmonics are generated in that device and/or equipment. Moreover, differential or added frequencies occur in the device due to mixing of harmonics or
22、 a harmonic and the fundamental frequency. These resultant frequencies create noise causing interference. In transmitter/receiver duplexing systems and radio relay systems, many frequencies are allocated to a specified band so that combinations of transmitting frequencies and harmonics may fall on t
23、he receiving band. This causes deterioration of communication quality due to intermodulation. Since the intermodulation interferences cannot be prevented by filtering, it is important to evaluate the intermodulation products level of the device to be employed in such a system. 2 Principle of measure
24、ment When a number of different frequencies, denoted by subscript i, exist, intermodulation frequency (f out ) is represented as follows: f out= n 1f 1 n 2f 2 . n i f i where n 1 , n 2 ,.,n iare integers. Since, in many cases, third order intermodulation products are the most probable, the measuring
25、 method for third order intermodulation will be described hereinafter. Two signals of specified power levels and frequencies (f 1and f 2 ) are combined utilizing a power combiner. The residual intermodulation product(2f 1 f 2or 2f 2 f 1 ) of the measuring system by connecting the combined signal dir
26、ectly to receiver should be less than 90 dBm.Then the intermodulation product of device under test is determined by connecting the device between the signal source and receiver. 3 Measuring arrangement The measuring arrangement is shown in Figure 1. It comprises two generators with specified power l
27、evels and frequencies, a power combiner, a low-pass filter, band-pass filters, a receiver and other components. Use of components with low insertion loss, lowest possible intermodulation product and adequate power handling capability is recommended. Requirements for the individual components are as
28、follows: 3.1 Generators (1 and 2) It is required that power levels at port A and frequencies are specified to simulate practical conditions causing intermodulation products. The recommended conditions are shown on Table 1. 3.2 Directional couplers 3.2.1 Directional couplers (1, 2 and 3) These couple
29、rs are used to provide partial power from the generator to the frequency meter and the power meter for monitoring. 3.2.2 Directional coupler (4) This coupler is used to reduce the power entering the receiver and to suppress the influence of fundamental signal reflection from the band-pass filter 3.
30、3.3 Frequency meters (1 and 2) These frequency meters are used to monitor the frequencies of the generators. A resonant cavity type wave meter or digital frequency counter is recommended. 3.4 Power meters 3.4.1 Power meters (1 and 2) These power meters are used to monitor the power levels of the gen
31、erators. 3.4.2 Power meter (3) This power meter is used to set the output level at port A. Table 1 Recommended conditions for generators Application Frequency band Power Separation of frequency Land mobile system 400 MHz, 800 MHz 1,5 GHz 1 W to 40 W 4 MHz to 130 MHz Microwave relay system 4, 5, 6, 1
32、1, 15, 20GHz 1 W to 4 W 160 MHz Satellite broadcast and communication system 4, 6, 12, 14, 20, 30GHz 30 W to 300 W 160 MHzEN61843:1997 4 BSI 03-2000 3.5 Band-pass filters 3.5.1 Band-pass filters (1 and 2) These filters are used to eliminate unwanted spectra of the fundamental signals. Attenuation of
33、40 dB or more is required in the out of band range. 3.5.2 Band-pass filter (3) This filter is used to prevent high level fundamental signals from entering into the receiver. Attenuation of 30 dB or more is required at fundamental signal frequencies. 3.6 Low-pass filter This filter is used to elimina
34、te higher harmonics contained in the source signals. Attenuation of40dB or more is required at second harmonics. 3.7 Variable attenuators 3.7.1 Variable attenuators (1 and 2) These attenuators are used to adjust the source signal power to specified level at port A. 3.7.2 Variable attenuator (3) This
35、 attenuator is used to adjust the input level entering into the receiver. 3.8 Power combiner It is a device, such as 3 dB hybrid or transmitting duplexer, which combines two signals having different frequencies (f 1and f 2 ). 3.9 Receiver It comprises a low distortion down converter, a low-noise hig
36、h gain wide dynamic range amplifier and a display section. A spectrum analyzer with a noise level less than 100 dBm and a third intermodulation product less than 100 dB is recommended as the receiver. 4 Measuring procedure a) Adjust the frequencies of the two generators to specified ones with the ai
37、d of a frequency meter. b) Connect port A to port B directly and adjust thepower level of the generators individually tospecified levels using the variable attenuators(1and 2). During the adjustment, the remaining generator should be turned off to ensure proper setting. c) Connect port A to port C d
38、irectly, and measure the intermodulation product at frequencies of 2f 1 f 2and 2f 2 f 1 . When the product is larger than 90 dBm, try to reduce the product by means of fastening uncertain contacts and exchanging components, if necessary. d) Connect the device under test between port A and port C, an
39、d measure the intermodulation products on the display of the receiver. 5 Expression of results The results are expressed in decibels referred to one milliwatt (dBm) for the frequencies and level of source signal.EN61843:1997 BSI 03-2000 5 Figure 1 Measuring arrangement for intermodulation productsBS
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