1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationSuperconductivityPart 16: Electric characteristic measurements Power-dependent surface resistance of superconductors at microwave frequenciesBS EN 61788-16:2013National forewordT
2、his British Standard is the UK implementation of EN 61788-16:2013. It is identical to IEC 61788-16:2013. The UK participation in its preparation was entrusted to Technical Committee L/-/90, Super Conductivity.A list of organizations represented on this committee can be obtained on request to its sec
3、retary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2013.Published by BSI Standards Limited 2013.ISBN 978 0 580 69203 1 ICS 17.220.20; 29.050Compliance with a British Stan
4、dard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 April 2013.Amendments issued since publicationDate Text affectedBRITISH STANDARDBS EN 61788-16:2013EUROPEAN STANDARD EN 61788-16 NORME EUROP
5、ENNE EUROPISCHE NORM April 2013CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Management Centre: Avenue Marnix 17, B - 1000 Brussels 2013 CENELEC - All rights of exploitation in any form
6、 and by any means reserved worldwide for CENELEC members. Ref. No. EN 61788-16:2013 E ICS 17.220.20; 29.050 English version Superconductivity - Part 16: Electronic characteristic measurements - Power-dependent surface resistance of superconductors at microwave frequencies (IEC 61788-16:2013) Supraco
7、nductivit - Partie 16: Mesures de caractristiques lectroniques - Rsistance de surface des supraconducteurs aux hyperfrquences en fonction de la puissance (CEI 61788-16:2013) Supraleitfhigkeit - Teil 16: Messung der elektronischen Eigenschaften - Leistungsabhngiger Oberflchenwiderstand bei Mikrowelle
8、nfrequenzen (IEC 61788-16:2013) This European Standard was approved by CENELEC on 2013-02-20. 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
9、-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by tran
10、slation under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
11、Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN
12、61788-16:2013EN 61788-16:2013 Foreword The text of document 90/309/FDIS, future edition 1 of IEC 61788-16, prepared by IEC TC 90,“Superconductivity“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC asEN 61788-16:2013. The following dates are fixed: latest date by which the docu
13、ment has to be implemented at national level bypublication of an identical national standard or by endorsement (dop) 2013-11-20 latest date by which the national standards conflicting with thedocument have to be withdrawn (dow) 2016-02-20 Attention is drawn to the possibility that some of the elemen
14、ts of this document may be the subject ofpatent rights. CENELEC and/or CEN shall not be held responsible for identifying any or all such patentrights. Endorsement notice The text of the International Standard IEC 61788-16:2013 was approved by CENELEC as a EuropeanStandard without any modification. B
15、S EN 61788-16:2013EN 61788-16:2013 Annex ZA (normative) Normative references to international publicationswith their corresponding European publications The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated refe
16、rences, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HDapplies. Year Publication EN/HD Ti
17、tle Year Series IEC 60050 International electrotechnical vocabulary - - IEC 61788-15 Superconductivity - - Part 15: Electronic characteristicmeasurements - Intrinsic surface impedance of superconductor films at microwavefrequencies EN 61788-15 - BS EN 61788-16:201361788-16 IEC:2013 CONTENTS INTRODUC
18、TION . 6 1 Scope . . 7 2 Normative references . 7 3 Terms and definitions . 7 4 Requirements . 8 5 Apparatus . 8 5.1 Measurement system . 8 5.1.1 Measurement system for the tan of the sapphire rod . . 8 5.1.2 Measurement system for the power dependence of the surface resistance of superconductors at
19、 microwave frequencies 9 5.2 Measurement apparatus . . 10 5.2.1 Sapphire resonator 10 5.2.2 Sapphire rod . 10 5.2.3 Superconductor films . . 11 6 Measurement procedure . 11 6.1 Set-up . 11 6.2 Measurement of the tan of the sapphire rod . . 11 6.2.1 General . 11 6.2.2 Measurement of the frequency res
20、ponse of the TE021mode . 11 6.2.3 Measurement of the frequency response of the TE012mode . 13 6.2.4 Determination of tan of the sapphire rod . . 13 6.3 Power dependence measurement . 14 6.3.1 General . 14 6.3.2 Calibration of the incident microwave power to the resonator. 15 6.3.3 Measurement of the
21、 reference level 15 6.3.4 Surface resistance measurement as a function of the incident microwave power . 15 6.3.5 Determination of the maximum surface magnetic flux density 15 7 Uncertainty of the test method . . 16 7.1 Surface resistance. 16 7.2 Temperature . 17 7.3 Specimen and holder support stru
22、cture . . 18 7.4 Specimen protection . 18 8 Test report 18 8.1 Identification of the test specimen . 18 8.2 Report of power dependence of Rsvalues 18 8.3 Report of test conditions . . 18 Annex A (informative) Additional information relating to Clauses 1 to 7 . . 19 Annex B (informative) Uncertainty
23、considerations . . 24 Bibliography . 29 Figure 1 Measurement system for tan of the sapphire rod . . 9 Figure 2 Measurement system for the microwave power dependence of the surface resistance . . 9 BS EN 61788-16:201361788-16 IEC:2013 Figure 3 Sapphire resonator (open type) to measure the surface res
24、istance of superconductor films 10 Figure 4 Reflection scattering parameters (|S11| and |S22|) . . 13 Figure 5 Term definitions in Table 3 . 17 Figure A.1 Three types of sapphire rod resonators 19 Figure A.2 Mode chart for a sapphire resonator (see IEC 61788-15) . 20 Figure A.3 Loaded quality factor
25、 QLmeasurements using the conventional 3 dB method and the circle fit method 21 Figure A.4 Temperature dependence of tan of a sapphire rod measured using the two-resonance mode dielectric resonator method 3 . . 22 Figure A.5 Dependence of the surface resistance Rson the maximum surface magnetic flux
26、 density Bs max3 . 23 Table 1 Typical dimensions of the sapphire rod 11 Table 2 Specifications of the vector network analyzer . . 16 Table 3 Specifications of the sapphire rods . . 17 Table B.1 Output signals from two nominally identical extensometers . 25 Table B.2 Mean values of two output signals
27、 . 25 Table B.3 Experimental standard deviations of two output signals 25 Table B.4 Standard uncertainties of two output signals 26 Table B.5 Coefficient of Variations of two output signals 26 BS EN 61788-16:2013 6 61788-16 IEC:2013 INTRODUCTION Since the discovery of high-Tcsuperconductors (HTS), e
28、xtensive researches have been performed worldwide for electronic applications and large-scale applications. In the fields of electronics, especially in telecommunications, microwave passive devices such as filters using HTS are being developed and testing is underway on sites 1,2,3,41. Superconducto
29、r materials for microwave resonators, filters, antennas and delay lines have the advantage of ultra-low loss characteristics. Knowledge of this parameter is vital for the development of new materials on the supplier side and the design of superconductor microwave components on the customer side. The
30、 parameters of superconductor materials needed to design microwave components are the surface resistance Rsand the temperature dependence of the Rs. Recent advances in HTS thin films with Rs, several orders of magnitude lower than normal metals has increased the need for a reliable characterization
31、technique to measure this property 5,6. Among several methods to measure the Rsof superconductor materials at microwave frequencies, the dielectric resonator method 7,8,9 has been useful due to that the method enables to measure the Rsnondestructively and accurately. In particular, the sapphire reso
32、nator is an excellent tool for measuring the Rsof HTS materials 10. In 2002, the International Electrotechnical Commission (IEC) published the dielectric resonator method as a measurement standard 11. The test method given in this standard enables measurement of the power-dependent surface resistanc
33、e of superconductors at microwave frequencies. For high power microwave device applications such as those of transmitting devices, not only the temperature dependence of Rsbut also the power dependence of Rsis needed to design the microwave components. Based on the measured power dependence, the RF
34、current density dependence of the surface resistance can be evaluated. The simulation software to design the device gives the RF current distribution in the device. The results of the power dependence measurement can be directly compared with the simulation and allow the power handling capability of
35、 the device to be evaluated. The test method given in this standard can be also applied to other superconductor bulk plates including low-Tcmaterial. This standard is intended to give an appropriate and agreeable technical base for the time being to those engineers working in the fields of electroni
36、cs and superconductivity technology. The test method covered in this standard is based on the VAMAS (Versailles Project on Advanced Materials and Standards) pre-standardization work on the thin film properties of superconductors. _ 1Numbers in square brackets refer to the Bibliography. BS EN 61788-1
37、6:201361788-16 IEC:2013 7 SUPERCONDUCTIVITY Part 16: Electronic characteristic measurements Power-dependent surface resistance of superconductors at microwave frequencies 1 Scope This part of IEC 61788 involves describing the standard measurement method of power-dependent surface resistance of super
38、conductors at microwave frequencies by the sapphire resonator method. The measuring item is the power dependence of Rsat the resonant frequency. The following is the applicable measuring range of surface resistances for this method: Frequency: f 10 GHz Input microwave power: Pin) IEC 61788-15, Super
39、conductivity Part 15: Electronic characteristic measurements Intrinsic surface impedance of superconductor films at microwave frequencies 3 Terms and definitions For the purposes of this document, the definitions given in IEC 60050-815, one of which is repeated here for convenience, apply. 3.1 surfa
40、ce impedance impedance of a material for a high frequency electromagnetic wave which is constrained to the surface of the material in the case of metals and superconductors Note 1 to entry: The surface impedance governs the thermal losses of superconducting RF cavities. Note 2 to entry: In general,
41、surface impedance Zsfor conductors including superconductors is defined as the ratio of the electric field Etto the magnetic field Ht, tangential to a conductor surface: Zs= Et/Ht = Rs+ jXs, where Rsis the surface resistance and Xsis the surface reactance. BS EN 61788-16:2013 8 61788-16 IEC:2013 4 R
42、equirements The surface resistance Rsof a superconductor film shall be measured by applying a microwave signal to a sapphire resonator with the superconductor film specimen and then measuring the insertion attenuation of the resonator at each frequency. The frequency shall be swept around the resona
43、nt frequency as the center and the insertion attenuation - frequency characteristics shall be recorded to obtain the Q-value, which corresponds to the loss. The target relative combined standard uncertainty of this method is the coefficient of variation (standard deviation divided by the average of
44、the surface resistance determinations), which is less than 20 % for a measurement temperature range from 30 K to 80 K. It is the responsibility of the user of this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prio
45、r to use. Hazards exist in such measurement. The use of a cryogenic system is essential to cool the superconductors and allow transition into the superconducting state. Direct contact of skin with cold apparatus components can cause immediate freezing, as can direct contact with a spilled cryogen. T
46、he use of an RF-generator is also essential to measure the high-frequency properties of materials. If its power is excessive, direct contact to human bodies could cause immediate burns. 5 Apparatus 5.1 Measurement system 5.1.1 Measurement system for the tan of the sapphire rod Figure 1 shows a schem
47、atic diagram of the system required for the tan measurement. The system consists of a network analyzer system for transmission measurements, a measurement apparatus in which a sapphire resonator with superconductor films is fixed, and a thermometer for monitoring the measuring temperature. The incid
48、ent power generated from a suitable microwave source such as a synthesized sweeper is applied to the sapphire resonator fixed in the measurement apparatus. The transmission characteristics are shown on the display of the network analyzer. The measurement apparatus is fixed in a temperature-controlle
49、d cryocooler. To measure the tan of the sapphire rod, a vector network analyzer is recommended, since its measurement accuracy is superior to a scalar network analyzer due to its wide dynamic range. BS EN 61788-16:201361788-16 IEC:2013 9 Cryocooler Thermal sensor Measurement apparatus Vector network analyzer Thermometer Synthesized sweeper S-parameter test set SysteminterfaceIEC 003/13 Figure 1 Measurement system for tan of the sapphire rod 5
