1、BRITISH STANDARD BS EN 60835-2-3:1995 BS 7573-2.3: 1995 IEC 835-2-3: 1992 Incorporating Amendment No. 1 Methods of measurement for equipment used in digital microwave radio transmission systems Part 2: Measurements on terrestrial radio-relay systems Section 2.3 RF branching networks The European Sta
2、ndard EN60835-2-3:1993has the status of a British Standard UDC 621.396.6:629.783:621.317.08BSEN60835-2-3:1995 This British Standard, having been prepared under the directionof the Electronic Equipment Standards Policy Committee, was published underthe authority of the Standards Board and comes into
3、effect on 15May1993 BSI 03-2000 The following BSI references relate to the work on this standard: Committee reference EEL/25 Draft for comment 90/33696 DC ISBN 0 580 21800 7 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Electronic Equi
4、pment Standards Policy Committee (EEL/-) to Technical Committee EEL/25, upon which the following bodies were represented: British Broadcasting Corporation British Radio and Electronic Equipment Manufacturers Association British Telecommunications plc Institution of Electrical Engineers Radio, Electr
5、ical and Television Retailers Association Radiocommunications Agency The following body was also represented in the drafting of the standard through subcommittees and panels: ERA Technology Ltd. Amendments issued since publication Amd. No. Date Comments 8692 August 1995 Indicated by a sideline in th
6、e marginBSEN60835-2-3:1995 BSI 03-2000 i Contents Page Committees responsible Inside front cover National foreword ii 1 Scope 3 2 Definition and general considerations 3 3 Return-loss/frequency characteristic 4 4 In-band characteristics 4 5 Isolation 4 6 Multi-carrier intermodulation products 4 Figu
7、re 1 Block diagram showing an example of an RF branching network incorporating filters 5 Table 1 Items usually measured between different ports 3 List of references Inside back coverBSEN60835-2-3:1995 ii BSI 03-2000 National foreword This Section of BS7573has been prepared under the direction of the
8、 Electronic Equipment Standards Policy Committee. It is identical with IEC835-2-3 Methods of measurement for equipment used in digital microwave radio transmission systems Part 2: Measurements on terrestrial radio-relay systems Section 3: RF branching networks, published by the International Electro
9、technical Commission (IEC). In 1993 the European Committee for Electrotechnical Standardization (CENELEC) accepted IEC835-2-3:1992 as European Standard EN60835-2-3:1993. As a consequence of implementing the European Standard this British Standard is renumbered as BSEN60835-2-3 and any reference to B
10、S7573-2.3 should be read as a reference to BSEN60835-2-3. BS 7573 is published in three Parts. The other Parts are: Part 1: Measurements common to terrestrial radio-relay systems and satellite earth stations; Part 3: Measurements on satellite earth stations. This Section of BS7573 is intended to be
11、used in conjunction with BS7573-1.2 and BS7573-1.3. A British Standard does not purport to include all the necessary provisions 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 ob
12、ligations. Cross-references International Standard Corresponding British Standard IEC 835-1-2:1992 BS 7573 Methods of measurement for equipment used in digital microwave radio transmission systems Section 1.2:1993 Basic characteristics (Identical) IEC 835-1-3:1992 Section 1.3:1993 Transmission chara
13、cteristics (Identical) Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theEN title page, pages 2 to 6, 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 indi
14、cated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 60835-2-3 August 1993 UDC 621.396.6:629.783:621.317.08 Descriptors: Radiocommunications, telecommunications, communication equipment, earth stations, radio-relay systems, radio frequencies, te
15、sts, characteristics, measurements English version Methods of measurement for equipment used in digital microwave radio transmission systems Part 2: Measurements on terrestrial radio-relay systems Section 3: RF branching networks (IEC 835-2-3:1992) Mthodes de mesure applicables au matriel utilis pou
16、r les systmes de transmission numrique en hyperfrquence Partie 2: Mesures applicables aux faisceaux hertziens terrestres Section 3: Dispositifs de branchement aux frquences radiolectriques (CEI 835-2-3:1992) Meverfahren fr Gerte in digitalen Mikrowellen-Fnkubertragungssytemen Teil 2: Messungen an te
17、rrestrischen Richtfunksystemen Hauptabschnitt 3: RF-Verzweigungsnetzwerke (IEC 835-2-3:1992) This European Standard was approved by CENELEC on1993-07-06. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the
18、 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 three official versions (English, French, Ger
19、man). 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 versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark
20、, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnisc
21、he Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1993 Copyright reserved to CENELEC members Ref. No. EN 60835-2-3:1993 EEN60835-2-3:1993 2 BSI 03-2000 Foreword The CENELEC questionnaire procedure, performed for finding out whether or not the International Standard IEC835-2-3:1993
22、could be accepted without textural changes, has shown that no common modifications were necessary for the acceptance as European Standard. The reference document was submitted to the CENELEC members for formal vote and was approved by CENELEC as EN60835-2-3 on6July1993. The following dates were fixe
23、d: Annexes designated “normative” are part of the body of the standard. In this standard, Annex ZA is normative. latest date of publication of an identical national standard (dop) 1994-08-01 latest date of withdrawal ofconflicting national standards (dow) 1994-08-01EN60835-2-3:1993 BSI 03-2000 3 1 S
24、cope This section of IEC 835-2 deals with methods of measurement for branching networks used in digital radio-relay systems. 2 Definition and general considerations A branching network is a multi-port network which provides the means to connect several transmitters and receivers, operating at differ
25、ent frequencies, to a common antenna feeder. An example of a branching network is shown in Figure 1, where it will be seen that the network is made up of a transmit branching assembly, a receive branching assembly, and a transmit-receive coupler. The paths from T nto C and from C to R nhave pass-ban
26、d and stop-band characteristics, and usually need unidirectional devices such as circulators. All ports should be connected to the measuring equipment as described in the following clauses for measuring the branching network parameters. Due to the lengthy procedure of disconnecting many waveguide fl
27、anges, the measurements are usually made as type tests only. In some cases, the branching filters are integral with the transmit-receive equipment and therefore ports T nand R nmay not be accessible for measurement. In such cases, filters of exactly the same type may be substituted in the measuring
28、set-up shown in Figure 1. The ports between which the measurements are to be carried out are summarised as shown in Table 1 below and are described in the following clauses. Table 1 Items usually measured between different ports Output port: C T 1 T 2 . T n R 1 R 2 . R n Input port: C R F F F T 1 F
29、R I I I T 2 F R I I IT n F R I I I R 1 I R I I R 2 I I R IR n I I I R NOTER = return loss measurement (see clause3); F = forward characteristics measurement (see clause4); I = isolation measurement (see clause5).EN60835-2-3:1993 4 BSI 03-2000 3 Return-loss/frequency characteristic See IEC 835-1-2. T
30、he return-loss/frequency characteristic should be measured within the pass-band of each port of the branching network with all other ports terminated either by matched loads or by transmitters and receivers. 4 In-band characteristics 4.1 Insertion loss See IEC 835-1-2. The insertion loss should be m
31、easured between ports T nand C and between C and R n(see Figure 1), at the pass-band centre-frequency of the ports in question, with all other ports terminated either by matched loads or by transmitters and receivers. In some cases, when transmitter and receiver specifications are referred to the ci
32、rculator ports, the reference points T 1. T nand R 1. R nshould also be referred to these ports. 4.2 Amplitude/frequency characteristic See IEC 835-1-3. The amplitude/frequency characteristic should be measured between ports T nand C and between C and R n(see Figure 1), both within the pass-band and
33、 within the stop-band of the ports in question, with all other ports terminated by matched loads or by transmitters and receivers. 4.3 Group-delay/frequency characteristic See IEC 835-1-3. The group-delay/frequency characteristic should be measured between parts T nand C and between C and R n(see Fi
34、gure 1), within the pass-band of the pods in question with all other ports terminated by matched loads or by transmitters and receivers. NOTEThe amplitude and group-delay/frequency characteristic of a transmit-receive section, including the contribution of the transmit and receive branching networks
35、, may be measured between the i.f. ports. 5 Isolation See IEC 835-1-2. The isolation should be measured by applying a c.w. signal at a specified level and at a frequency corresponding to the centre-frequency of the pass-band to each transmit or receive port in turn and by measuring the level of the
36、unwanted signal at all receive ports. The remaining unconnected transmit and receive ports should be terminated by matched loads or by transmitters and receivers, and port C should be terminated by a load corresponding to the antenna feeder impedance. NOTEDepending upon the radio-frequency channel a
37、rrangement, only some of the above port combinations may be of interest. 6 Multi-carrier intermodulation products 6.1 Definition and general considerations Multi-carrier intermodulation products are unwanted signals at frequencies which are combinations of the transmit port frequencies and which fal
38、l into the pass-band of some receive ports, thus introducing interference into the receivers. These products may be generated by non-linearities in the waveguide system, such as imperfect flanges or joints, or in circulators. Two transmit frequencies f 1and f 2may generate, for example, the products
39、 2f 1 f 2or 2f 2 f 1while three transmit frequencies f 1 , f 2and f 3may generate, for example, the product f 1 f 2+ f 3 . Only some of these frequency combinations may be of interest, depending on the radio frequency channel arrangement. 6.2 Method of measurement Signals from two or three high-leve
40、l generators, at specified levels and at frequencies corresponding to the mid-band frequencies of the transmit parts, are applied to the appropriate transmit ports of the branching network. It is essential that generators having low harmonic levels be used in order to avoid the generation of additio
41、nal products which would not otherwise be present in the equipment under test. A calibrated spectrum analyser is connected to a designated receive port having a pass-band which includes one of the combination frequencies given in6.1. Port C should be terminated by a load having negligible non-linear
42、ity and a specified impedance corresponding to that presented by the antenna feeder. All other ports should be terminated by matched loads. The bandwidth of the spectrum analyser should be narrow enough to ensure that noise does not affect the accuracy of the measurement. The level of the intermodul
43、ation product is read from the calibrated display of the spectrum analyser. 6.3 Presentation of results The measured level of the intermodulation product(s) and the type of product (e.g. 2f 1 f 2 ), together with the applied transmit frequencies and levels, should be tabulated.EN60835-2-3:1993 BSI 0
44、3-2000 5 6.4 Details to be specified The following items should be included, as required, in the detailed equipment specification: a) frequencies and levels of signals applied to the transmit ports; b) frequency of the intermodulation product(s) to be measured together with the type of product (e.g.
45、 2f 1 f 2 ); c) maximum permitted level of the intermodulation product(s). Figure 1 Block diagram showing an example of an RF branching network incorporating filtersEN60835-2-3:1993 6 BSI 03-2000 Annex ZA (normative) Other international publications quoted in this standard with the references of the
46、 relevant European publications When the international publication has been modified by CENELEC common modifications, indicated by (mod), the relevant EN/HD applies. IEC Publication Date Title EN/HD Date 835-1-2 1992 Methods of measurement for equipment used in digital microwave radio transmission s
47、ystems Part 1: Measurements common to terrestrial radio-relay systems and satellite earth stations Section 2: Basic characteristics EN 60835-1-2 1993 835-1-3 1992 Section 3: Transmission characteristics BSEN60835-2-3:1995 BSI 03-2000 List of references See national foreword.BS EN 60835-2-3:1995 BS 7
48、573-2.3: 1995 IEC 835-2-3: 1992 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter.
49、 Revisions BritishStandards are updated by amendment or revision. Users of BritishStandards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this BritishStandard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel:02089969000. Fa
