1、Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 05/09/2008 02:21, Uncontrolled Copy, (c) BSIg49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58c
2、onnection Test methods Part 221: Voltage Standing Wave Ratio (VSWR)ICS 49.060Aerospace series Elements of electrical and optical BRITISH STANDARDBS EN 2591-221:2007BS EN 2591-221:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 05/09/2008 02:21, Uncontrolled Copy, (c) BSIThis British Stand
3、ard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2008 BSI 2008ISBN 978 0 580 56475 8Amendments/corrigenda issued since publicationDate CommentsCompliance with a British Standard cannot confer immunity from legal obligations.National forewordThis British
4、 Standard is the UK implementation of EN 2591-221:2007. The UK participation in its preparation was entrusted to Technical Committee ACE/6, Aerospace avionic electrical and fibre optic technology.A list of organizations represented on this committee can be obtained on request to its secretary.This p
5、ublication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 2591-221December 2007ICS 49.060English VersionAerospace series - Elements of electrical and optical connection- Test
6、methods - Part 221: Voltage Standing Wave Ratio(VSWR)Srie arospatiale - Organes de connexion lectrique etoptique - Mthodes dessais - Partie 221 : Ratio dOndesStationnairesLuft- und Raumfahrt - Elektrische und optischeVerbindungselemente - Prfverfahren - Teil 221:StehwellenverhltnisThis European Stan
7、dard was approved by CEN on 27 April 2006.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning suc
8、h nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language a
9、nd notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg
10、, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of ex
11、ploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 2591-221:2007: ELicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 05/09/2008 02:21, Uncontrolled Copy, (c) BSI2 Contents Page Foreword3 1 Scope 4 2 Normative references 4 3 Preparation of specimens.4
12、4 Apparatus .5 5 Procedure .6 6 Requirement.6 7 Detail to be specified.6 Annex A (normative) Definition of S parameters .8 BS EN 2591-221:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 05/09/2008 02:21, Uncontrolled Copy, (c) BSI3 Foreword This document (EN 2591-221:2007) has been prepar
13、ed by the Aerospace and Defence Industries Association of Europe - Standardization (ASD-STAN). After enquiries and votes carried out in accordance with the rules of this Association, this Standard has received the approval of the National Associations and the Official Services of the member countrie
14、s of ASD, prior to its presentation to CEN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by June 2008, and conflicting national standards shall be withdrawn at the latest by June 2008. Attention i
15、s drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the fo
16、llowing countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, S
17、lovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 2591-221:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 05/09/2008 02:21, Uncontrolled Copy, (c) BSI4 1 Scope This standard specifies a measurement method of VSWR, in the required frequency bandwidth of coax contacts or co
18、nnectors with characteristic impedance. It shall be used together with EN 2591-100. The measurement is carried out according to vectorial method using “S” parameters (see definition in Annex A). 2 Normative references The following referenced documents are indispensable for the application of this d
19、ocument. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 2591-100, Aerospace series Elements of electrical and optical connection Test methods Part 100: General. 3 Preparation of specim
20、ens Method “A” This method is applicable, when a calibrated adapter, for the series of connectors or contacts to be tested, exists. The sampling shall include, for each specified cable, one section of coaxial cable with device under test at both ends. The section is constituted/described only as fol
21、lows (see Figure 1): (600 2,5) mm of coaxial cable 1 male coaxial device 1 female coaxial device Key 1 Male coaxial device 2 Female coaxial device 3 Coaxial cable; Lg. = (600 2,5) mm Figure 1 BS EN 2591-221:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 05/09/2008 02:21, Uncontrolled Cop
22、y, (c) BSI5 Method “B” This method is applicable, when a calibrated adapter, for the series of connectors or contacts to be tested, exists. The sampling shall include for each specified cable, one section of coaxial cable with standard connectors at both end, and the device under test in the middle
23、of the section of the cable. The section is constituted/described only as follows (see Figure 2): (600 5) mm of coaxial cable divided in 2 (2 300 mm) 1 male coaxial standard connector (SMA, Nor TNC type ) 1 female coaxial standard connector (SMA, Nor TNC type ) 1 male coaxial device 1 female coaxial
24、 device Key 1 Coaxial (Std) male connector 2 Device under test 3 Coaxial (Std) female connector 4 Coaxial cable; Lg. = 2 (300 2,5) mm Figure 2 4 Apparatus The apparatus shall comprise measuring equipment which includes (see Figure 3): vector network analyser calibration kit standard precision adapte
25、rs a 75 kit of transformation, to perform measurement from 50 network analyser, when it is necessary. BS EN 2591-221:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 05/09/2008 02:21, Uncontrolled Copy, (c) BSI6 5 Procedure 5.1 Calibration Select frequency range to be measured and number o
26、f sampling points. Carry out the complete calibration of network analyser, Part 1 and Part 2 (“S” Parameters, S11, S12, S21and S22) using the calibration kit according to instructions specified by network analyser manufacturer. 5.2 Measurement Method A Connect the section in measure on network analy
27、ser, using if necessary, standards accurate adapters, and perform the measurement. The VSWR of one coaxial device is determined by using the temporal response (time domain) and a function called “GATE“ to isolate the coaxial device, which must be connected to the standard precision adapter. Method B
28、 Connect the section in measure on network analyser, using if necessary, standards accurate adapters, and perform measurement. The VSWR of the two mated coaxial devices is determined by using the temporal response (time domain) and a function called “GATE“ to isolate the two mated coaxial devices, f
29、rom the coaxial cable. 6 Requirement The Voltage Standing Wave Ratio (VSWR) does not exceed specified values in the product standard. 7 Detail to be specified The following items shall be specified: coaxial devices (contact or connector) part numbers coaxial cables part number standard coaxial conne
30、ctors part number network analyser, manufacturer, type and serial number frequency range sampling point number standard precision adapter part number measurement impedance (50 or 75 ) for coaxial contact, connection length wiring instruction and tooling for thread coupling connectors, the coupling t
31、orque of the coupling ring. BS EN 2591-221:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 05/09/2008 02:21, Uncontrolled Copy, (c) BSI7 Key 1 Vector network analyser 2 RF generator and “S” parameter test set Legend Precision hermaphroditic connectors Standard Precision Adapters Figure 3
32、Hermaphrodite Interface Standard Coaxial Connector Interface Device Under Test Interface BS EN 2591-221:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 05/09/2008 02:21, Uncontrolled Copy, (c) BSI8 Annex A (normative) Definition of S parameters A.1 Effective Power of a Sinusoidal source C
33、onsider an E.M.F. source, E, measured in Vrmswith an internal impedance Zgand a load impedance Z. The applied power P dissipated in Z is defined as () ()Z eZZE*Z*Z*EZZZEe*I V e Pggg+=+=22)()(P is a maximum when *ZZg= (balanced load). This maximum power is known as the effective or RMS nota Root Mean
34、 Squared power for a given source (E, Zg) and can be expressed as Prms= )(2gdZeEP=4In general, when Z has a different value to Zg, we define P as +=221)(gggZZ*Z-ZZeEP4where ggZZ*ZZ+is known as the Power Reflection Coefficient. The power dissipated in Z can be expressed as the difference of two power
35、s, and when the source (E, Zg) power is maximum and when Z Zg, the amount of power reflected towards the source is equal to 2ggZZ*Z-Z+BS EN 2591-221:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 05/09/2008 02:21, Uncontrolled Copy, (c) BSI9 A.2 Waves Incident and Reflected (Kurokawa Wav
36、es) Let us define an impedance, Z, in terms of a potential difference, V, and a current I. We also define an Incident Wave, a, and a Reflected Wave, b, with respect to a Reference Resistance, Rg, as follows: the power dissipated in Z = P = |a|2 |b|2 the effective power generated by the source (E, Rg
37、) = Prms= |a|2Expressing a and b in terms of V, I, Rg, gives: ggRI R Va2+= ggRI R Vb2= If Z is supplied by the source (E, Rg) we can state that E = V + Rg.I which automatically validates Prms = |a|2. NOTE - Rgis known as the Reference Resistance for the “waves“ a and b - The word wave is written ins
38、ide speech marks because a and b do not show the typical electromagnetic behaviour associated with classical waves they are rather Power Waves - The definition of a and b is independent of that fact that the dipole Z is fed by a source of an internal resistance Rg- The power dissipated in Z is indep
39、endent of the characteristics of the source and is always equal to |a|2|b|2- The ratio of the waves b to a is equal to (when V = Z.I) ggR ZR - Zab+= which is the Reflection Coefficient of the impedance Z with respect to the reference resistance Rg. BS EN 2591-221:2007Licensed Copy: Wang Bin, ISO/EXC
40、HANGE CHINA STANDARDS, 05/09/2008 02:21, Uncontrolled Copy, (c) BSI10 A.3 S Parameters of a quad pole Let us apply the precedent definition to the input and output of a quad pole device. This time we define an incident and reflected wave, a1and b1, for the input side and incident and reflected wave,
41、 a2and b2, for the output side, relative to the input and output reference resistances, R1and R2. 111112 R I RVa+= 222222 R I RVa+= 111112 R I RVb= 222222 R I RVb= We can state that the system is linear and we can therefore re-write the above equations to express on variable in function of two of th
42、e other unknowns. b1= S11 a1+ S12 a2b2= S21 a1+ S22 a2These S Parameters are also known as the system distribution parameters and characterise the quad pole in function of its input and output reference resistances, R1and R2. NOTE These S Parameters define the quad pole at a given frequency A.4 Phys
43、ical Signification and Interest of S Parameters A.4.1 Physical significance of S11If S11= b1/a1, where a2= 0, then a2is equivalent to V2= R2.I2, the output of the quad pole is therefore closed loop on R2and if Zeis the input impedance of Q, then in these conditions, we can state that V1 = Ze.I1and S
44、11is the input reflection coefficient with respect to R1when the output impedance = R2. 1111RZRZSee+=BS EN 2591-221:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 05/09/2008 02:21, Uncontrolled Copy, (c) BSI11 A.4.2 Physical significance of S22In the same way, if S22= b2/a2then when a1=
45、0, the input is closed loop on R1and under these conditions if Zois the output impedance, we obtain S22is the input reflection coefficient with respect to R2when the input impedance = R1. The Smmparameters are therefore defined as the Reflection Coefficients. A.4.3 Physical significance of S21If S21
46、= b2/a1then when a2= 0, the output is closed loop on R2and therefore 111222211221IRVIRVRRabS+= If we assume that the quad pole Q is supplied by a source (E, R1) then E = V1+ R1.I1and V2= R2.I2The quad pole being supplied by a source of impedance R1and with a load R2will have a S Parameter S21proport
47、ional to a voltage gain called the System Transmission Coefficient. If we take the square of S21then we obtain )/12122221222221RMS PowerinRMS Power 44R (E, R RERVRREVS = where |S21|2is the Composite Power Gain. 2222RZRZSss+= EVRRS221212= BS EN 2591-221:2007Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA
48、 STANDARDS, 05/09/2008 02:21, Uncontrolled Copy, (c) BSI12 A.4.4 Physical significance of S12We can do a similar calculation as above and we will find that, for a quad pole Q supplied by a source (E, R2) and whose input is closed loop on R1, the S12parameter is defined by EVRRS112212= S21is called t
49、he Inverse Transmission Coefficient. These S Parameters are used to characterise the junctions in high frequency applications because they possess a number of advantages: these parameters are measurable at R1and R2. In practice we choose standard values for resistances R1and R2such as 50 ohms or 75 ohms. It is much easier to measure variables over a known resistance than on an open circuit (Z Parameters) or in a short circuit (Y Parameters); in
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