1、AECMA STANDARD NORME AECMA AECMA NORM Edition approved for publication 28 February 2005 prEN 2591 -222 Edition P 1 February 2005 Comments should be sent within six months after the date of publication to AECMA-STAN ICs: Descriptors: ENGLISH VERSION Aerospace series Elements of electrical and optical
2、 connection Test methods Part 222: Insertion Loss (I.L.) Srie arospatiale Luft- und Raumfahrt Organes de connexion lectrique et optique Mthodes dessais Partie 222 : Pertes dinsertion Elektrische und optische Verbindungselemente P rfverfa h ren Teil 222: Einfgungsdmpfung This Xerospace Series“ Presta
3、ndard has been drawn up under the responsibility of AECMA-STAN (The European Association of Aerospace Industries - Standardization). It is published for the needs of the European Aerospace Industry. It has been technically approved by the experts of the concerned Domain following member comments. Su
4、bsequent to the publication of this Prestandard, the technical content shall not be changed to an extent that interchangeability is affected, physically or functionally, without re-identification of the standard. After examination and review by users and formal agreement of AECMA-STAN, it will be su
5、bmitted as a draft European Standard (prEN) to CEN (European Committee for Standardization) for formal vote and transformation to full European Standard (EN). The CEN national members have then to implement the EN at national level by giving the EN the status of a national standard and by withdrawin
6、g any national standards conflicting with the EN. Electrical Domain I I Copyright 2005 O by AECMA-STA/ Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
7、Page 2 prEN 2591-222:2005 Foreword This standard was reviewed by the Domain Technical Coordinator of AECMA-STANS Electrical Domain. After inquiries and votes carried out in accordance with the rules of AECMA-STAN defined in AECMA- STANS General Process Manual, this standard has received approval for
8、 Publication. Contents Page 1 Scope 2 Normative referen ces . 3 Preparation of specimens . 4 Apparatus 5 Proced Ure . . 6 Requirement . 7 Detail to be specified Annex A (normative) Definition of S parameters Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS un
9、der license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Page 3 prEN 2591-222:2005 1 Scope This standard specifies a measurement method of insertion loss, in the required frequency bandwith of coax contacts or connectors with characteristic impedance.
10、It shall be used together with EN 2591-100. The measurement is carried out according to vectorial method using Y parameters (see definition in Annex A). 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the ed
11、ition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 2591 -1 00, Aerospace series - Elements of electrical and optical connection - Test methods - Part 100: General 3 Preparation of specimens The sampling shall include, for
12、 each specified cable, a minimum of two section of coaxial cable with connector in both ends. The first section called “Reference” is constituted as follow (see Figure 1): - 60 cm k 2,5 mm of coaxial cable - 1 male coaxial connector (SMA, N or TNC type . . .) - 1 female coaxial connector (SMA, N or
13、TNC type . . .) 1 2 3 Key 1 Coaxial (Std) female connector 2 Coaxial (Std) male connector 3 Coaxial cable; Lg. = 60 cm f 2,5 mm Figure 1 1) Published as AECMA Prestandard at the date of publication of this standard Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by
14、 IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Page 4 prEN 2591-222:2005 The coaxial connectors shall be selected to offer optimum performances for each used cable and measured frequency range. They must have a reflection coefficient b
15、etter than 0,l (- 20 dB) in the test frequency rouge. It is necessary to use the same type of connector on each section of cable. The second section called “Measure” (see Figure 2) is constituted by the same elements as “Reference Section”, the sample to be measured shall be installed in the middle
16、of the section of the cable. I 2 3 4 4 Key 1 Coaxial (Std) female connector 2 Device under test 3 Coaxial (Std) male connector 4 Coaxial cable; Lg. = 2 x 30 cm f 2,5 mm Figure 2 4 Apparatus The apparatus shall comprise: Measure equipment include (see Figure 3): - vector network analyser - calibratio
17、n kit - standard precision adapters - a 75 SZ kit of transformation, to perform measurement from 50 SZ network analyser, when it is necessary. 5 Procedu re 5.1 Cali bration Select measure frequency range and sampling points number. Carry out the complete calibration of network analyse, Part 1 and Pa
18、rt 2 (YParameters, SI1, SI2, SZ1 and SZ2) Using calibration kit according to instructions specified by network analyser manufacturer. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitte
19、d without license from IHS-,-,-Page 5 prEN 2591-222:2005 5.2 Measurement Connect reference section on network analyser, using if necessary, standard precision adapter. Perform the measurement, and run the curves tracer or record the values (,Yl2, ,Yz1 parameters). Move ?reference section?, connect t
20、he ?measure section? on the equipment, run the measurement and curve tracer, or record the values as above. 6 Sample insertion loss, which is measured, is the result of: (section insertion loss - reference insertion loss). Req u i remen t Insertion loss shall not exceed the values specified in the p
21、roduct standard. (The insertion loss of one contact or connector shall be the insertion loss of the contact or connector pair divided by two). 7 Detail to be specified The following items shall be specified: - coaxial cables part number - standard coaxial connectors part number - network analyser, m
22、anufacturer, type and serial number - frequency range - sampling point number - standard precision adapter part number - measurement impedance (50 Q or 75 Q) - for coaxial contact, connection length - wiring instruction and tooling - for thread coupling connectors, the coupling torque of the couplin
23、g ring Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Page 6 prEN 2591-222:2005 Key 1 Vector network analyser 2 RF generator and 3” parameter test set
24、 Legend Precision hermaphroditic connectors Standard Precision Adapters Hermaphrodite Standard Coaxial I nt e rface Connector Interface Device Under Test Interface Figure 3 Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for Resal
25、eNo reproduction or networking permitted without license from IHS-,-,-Page 7 prEN 2591-222:2005 Annex A (normative) Definition of S parameters A.l Consider an E.M.F. source, E, measured in V, with an internal impedance Z, and a load impedance Z. Effective Power of a Sinusoidal source The applied pow
26、er P dissipated in Z is defined as JEJ %e(z) (Z+Z,) EZ (Z*+Zg E* *) 1 = Iz+z,I P=%e(VI*) = %e P is a maximum when Z = Z, * (balanced load). This maximum power is known as the effective or RMS nota - Root Mean Squared power for a given source (E, Z,) and can be expressed as In general, when Z has a d
27、ifferent value to Z, we define P as z-z, * P= 4 lE12 1 l-lz+zg I where z-z, * Z+Z, is known as the Power Reflection Coefficient. The power dissipated in Z can be expressed as the difference of two powers, and when the source (E, Z,) power is maximum and when Z Z, the amount of power reflected toward
28、s the source is equal to Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Page 8 prEN 2591-222:2005 A.2 Waves - Incident and Reflected (Kurokawa Waves)
29、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, R, as follows: - the power dissipated in Z= P = laI2 - lbI2 - the effective power generated by the source (E, R,
30、) = P, = laI2 Expressing a and b in terms of V, I, R, gives: V+R, I V-R, I a= 2JR, 2 If Z is supplied by the source (E, R,) we can state that E = V+ R,.Iwhich automatically validates i,= la1 . NOTE - - R, is known as the Reference Resistance for the “waves“ a and b The word wave is written inside sp
31、eech 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 2 is fed by a source of an internal resistance R, The power dissipated in 2 is independent o
32、f the characteristics of the source and is always equal to la12-lb12 The ratio of the waves b to a is equal to (when V= 2.4 - - - b Z-R, a Z+R, _- - which is the Reflection Coefficient of the impedance 2 with respect to the reference resistance R,. Copyright Association Europeene des Constructeurs d
33、e Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Page 9 prEN 2591-222:2005 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 w
34、e define an incident and reflected wave, al and bl, for the input side and incident and reflected wave, a2 and b2, for the output side, relative to the input and output reference resistances, RI and R2. We can state that the system is linear and we can therefore re-write the above equations to expre
35、ss on variable in function of two of the other unknowns. These S Parameters are also known as the system distribution parameters and characterise the quad pole in function of its input and output reference resistances, RI and R2. NOTE These S Parameters define the quad pole at a given frequency A.4
36、Physical Signification and Interest of S Parameters A.4.1 Physical significance of SI, If SI1 = bl/al, where a2 = O, then a2 is equivalent to V2 = - R2.12, the output of the quad pole is therefore closed loop on R2 and if Z, is the input impedance of Q, then in these conditions, we can state that VI
37、 = Zell and SI1 is the input reflection coefficient with respect to RI when the output impedance = R2. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
38、Page 10 prEN 2591-222:2005 A.4.2 Physical significance of S22 In the same way, if SZ2 = b2/u2 then when al = O, the input is closed loop on RI and under these conditions if Z, is the output impedance, we obtain SZ2 is the input reflection coefficient with respect to R2 when the input impedance = RI.
39、 The S, parameters are therefore defined as the Reflection Coefficients. A.4.3 Physical significance of S21 If SZ1 = b2/ul then when u2 = O, the output is closed loop on R2 and therefore If we assume that the quad pole Q is supplied by a source (E, RI) then E = VI + R1.Il and V2 = - R2.12 The quad p
40、ole being supplied by a source of impedance RI and with a load R2 will have a S Parameter S2, proportional to a voltage gain called the System Transmission Coefficient. If we take the square of SZ1 then we obtain where IS2112 is the Composite Power Gain. Copyright Association Europeene des Construct
41、eurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Page 11 prEN 2591-222:2005 A.4.4 Physical significance of Sq2 We can do a similar calculation as above and we will find that, for a quad pole (2 sup
42、plied by a source (E, R2) and whose input is closed loop on RI, the SI2 parameter is defined by Sz1 is called the 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
43、 are measurable at RI and R2. In practice we choose standard values for resistances RI and R2 such 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 closing each side of the circuit
44、allows frequency sweeping. - as the termination resistances RI and R2 are dissipative, the risks of instability during the analysis of the active quad pole are decreased (which is not the case for open or short-circuits). - a simple device already exists to separate a and b waves at high frequencies. This device is the directional coupler. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
