SIST EN IEC 61788-7:2020

SLOVENSKI STANDARD
SIST EN IEC 61788-7:2020
01-julij-2020
Nadomešča:
SIST EN 61788-7:2007
Superprevodnost - 7. del: Meritve elektronskih lastnosti - Površinska upornost
visokotemperaturnih superprevodnikov pri mikrovalovnih frekvencah (IEC 61788-
7:2020)
Superconductivity - Part 7: Electronic characteristic measurements - Surface resistance
of high-temperature superconductors at microwave frequencies (IEC 61788-7:2020)
Supraleitfähigkeit - Teil 7: Charakteristische elektronische Messungen -
Oberflächenwiderstand von Supraleitern bei Frequenzen im Mikrowellenbereich (IEC
61788-7:2020)
Supraconductivité - Partie 7: Mesures des caractéristiques électroniques - Résistance de
surface des supraconducteurs aux hyperfréquences (IEC 61788-7:2020)
Ta slovenski standard je istoveten z: EN IEC 61788-7:2020
ICS:
17.220.20 Merjenje električnih in Measurement of electrical
magnetnih veličin and magnetic quantities
29.050 Superprevodnost in prevodni Superconductivity and
materiali conducting materials
SIST EN IEC 61788-7:2020 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN IEC 61788-7:2020

---------------------- Page: 2 ----------------------
SIST EN IEC 61788-7:2020


EUROPEAN STANDARD EN IEC 61788-7

NORME EUROPÉENNE

EUROPÄISCHE NORM
May 2020
ICS 29.050; 17.220.20 Supersedes EN 61788-7:2006 and all of its amendments
and corrigenda (if any)
English Version
Superconductivity - Part 7: Electronic characteristic
measurements - Surface resistance of high-temperature
superconductors at microwave frequencies
(IEC 61788-7:2020)
Supraconductivité - Partie 7: Mesurages des Supraleitfähigkeit - Teil 7: Messungen der elektronischen
caractéristiques électronique - Résistance de surface des Charakteristik - Oberflächenwiderstand von
supraconducteurs haute température critique aux Hochtemperatur-Supraleitern bei Frequenzen im
hyperfréquences Mikrowellenbereich
(IEC 61788-7:2020) (IEC 61788-7:2020)
This European Standard was approved by CENELEC on 2020-04-24. 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 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 translation
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,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.


European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN IEC 61788-7:2020 E

---------------------- Page: 3 ----------------------
SIST EN IEC 61788-7:2020
EN IEC 61788-7:2020 (E)
European foreword
The text of document 90/447/FDIS, future edition 3 of IEC 61788-7, prepared by IEC/TC 90
"Superconductivity" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
EN IEC 61788-7:2020.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2021-01-24
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2023-04-24
document have to be withdrawn

This document supersedes EN 61788-7:2006 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.

Endorsement notice
The text of the International Standard IEC 61788-7:2020 was approved by CENELEC as a European
Standard without any modification.

2

---------------------- Page: 4 ----------------------
SIST EN IEC 61788-7:2020
EN IEC 61788-7:2020 (E)
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60050-815 - International Electrotechnical Vocabulary - - -
Part 815: Superconductivity

3

---------------------- Page: 5 ----------------------
SIST EN IEC 61788-7:2020

---------------------- Page: 6 ----------------------
SIST EN IEC 61788-7:2020




IEC 61788-7

®


Edition 3.0 2020-03




INTERNATIONAL



STANDARD




NORME



INTERNATIONALE
colour

inside










Superconductivity –

Part 7: Electronic characteristic measurements – Surface resistance of

high‑temperature superconductors at microwave frequencies




Supraconductivité –

Partie 7: Mesurages des caractéristiques électronique – Résistance de surface


des supraconducteurs haute température critique aux hyperfréquences













INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 17.220.20; 29.050 ISBN 978-2-8322-7917-5




Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

---------------------- Page: 7 ----------------------
SIST EN IEC 61788-7:2020
– 2 – IEC 61788-7:2020 © IEC 2020
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 8
4 Requirements . 8
5 Apparatus . 9
5.1 Measurement system . 9
5.2 Measurement apparatus for R . 10
s
5.3 Dielectric rods . 12
6 Measurement procedure . 12
6.1 Specimen preparation . 12
6.2 Set-up . 13
6.3 Measurement of reference level . 13
6.4 Measurement of the frequency response of resonators . 14
6.5 Determination of surface resistance of the superconductor and ε′ and tan δ
of the standard sapphire rods. 16
7 Uncertainty of the test method . 17
7.1 Surface resistance . 17
7.2 Temperature . 18
7.3 Specimen and holder support structure . 18
7.4 Specimen protection . 19
7.5 Uncertainty of surface resistance measured by standard two-resonator
method . 19
8 Test report . 19
8.1 Identification of test specimen . 19
8.2 Report of R values . 19
s
8.3 Report of test conditions . 19
Annex A (informative) Additional information relating to Clauses 1 to 8 . 20
A.1 Scope . 20
A.1.1 General . 20
A.1.2 Cylindrical cavity method [10] [17] . 20
A.1.3 Parallel-plates resonator method [18] [19] . 20
A.1.4 Microstrip-line resonance method [20] [21] . 20
A.1.5 Dielectric resonator method [22] [23] [24] [25] . 20
A.1.6 Image-type dielectric resonator method [26] [27] . 21
A.1.7 Two-resonator method [28] [29] . 22
A.2 Requirements . 22
A.3 Theory and calculation equations . 22
A.4 Apparatus . 25
A.5 Dimensions of the standard sapphire rods . 26
A.6 Dimension of the closed type resonator . 28
A.7 Sapphire rod reproducibility . 30
A.8 Test results . 30
A.9 Reproducibility of measurement method . 31

---------------------- Page: 8 ----------------------
SIST EN IEC 61788-7:2020
IEC 61788-7:2020 © IEC 2020 – 3 –
A.10 tan δ deviation effect of sapphire rods on surface resistance . 32
Annex B (informative) Evaluation of relative combined standard uncertainty for surface
resistance measurement . 34
B.1 Practical surface resistance measurement . 34
B.2 Determination of surface resistance of the superconductor . 35
B.3 Combined standard uncertainty . 36
B.3.1 General . 36
B.3.2 Calculation of c to c (12 GHz resonance at 20 K) . 36
2 5
B.3.3 Determination of u to u . 37
1 5
B.3.4 Combined relative standard uncertainty . 39
Bibliography . 41

Figure 1 – Schematic diagram of measurement system for temperature dependence of
R using a cryocooler . 9
s
Figure 2 – Typical measurement apparatus for R . 11
s
Figure 3 – Insertion attenuation, IA, resonant frequency, f , and half power bandwidth,
0
∆f, measured at T kelvin . 14
Figure 4 – Reflection scattering parameters (S and S ) . 16
11 22
Figure 5 – Term definitions in Table 4 . 18
Figure A.1 – Schematic configuration of several measurement methods for the surface
resistance . 21
Figure A.2 – Configuration of a cylindrical dielectric rod resonator short-circuited at
both ends by two parallel superconductor films deposited on dielectric substrates . 23
Figure A.3 – Computed results of the u-v and W-v relations for TE mode . 24
01p
Figure A.4 – Configuration of standard dielectric rods for measurement of R and tan δ . 25
s
Figure A.5 – Three types of dielectric resonators . 26
Figure A.6 – Mode chart to design TE resonator short-circuited at both ends by
011
parallel superconductor films [28] . 27
Figure A.7 – Mode chart to design TE resonator short-circuited at both ends by
013
parallel superconductor films [28] . 28
Figure A.8 – Mode chart for TE closed-type resonator [28] . 29
011
Figure A.9 – Mode chart for TE closed-type resonator [28] . 30
013
Figure A.10 – Temperature-dependent R of YBCO film with a thickness of 500 nm
s
and size of 25 mm square . 31
Figure A.11 – Temperature dependent R of YBCO film when R was measured three
s s
times. 32
Figure B.1 – Schematic diagram of TE and TE mode resonance . 34
011 013
Figure B.2 – Typical frequency characteristics of TE mode resonance . 35
011
Figure B.3 – Frequency characteristics of a resonator approximated by a Lorentz
distribution . 39

Table 1 – Typical dimensions of pairs of single-crystal sapphire rods for 12 GHz,
18 GHz and 22 GHz . 12
Table 2 – Dimensions of superconductor film for 12 GHz, 18 GHz, and 22 GHz . 13
Table 3 – Specifications for vector network analyzer . 17

---------------------- Page: 9 ----------------------
SIST EN IEC 61788-7:2020
– 4 – IEC 61788-7:2020 © IEC 2020
Table 4 – Specifications for sapphire rods . 17
Table A.1 – Standard deviation of the surface resistance calculated from the results of
Figure A.11 . 32
Table A.2 – Relationship between x, defined by Equation (A.12), and y, defined by
Equation (A.13) . 33

---------------------- Page: 10 ----------------------
SIST EN IEC 61788-7:2020
IEC 61788-7:2020 © IEC 2020 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

SUPERCONDUCTIVITY –

Part 7: Electronic characteristic measurements –
Surface resistance of high-temperature
superconductors at microwave frequencies

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attention of conformity. Independent certification bodies provide conformity
assessment service and, in some areas access to IEC marks of conformity. IEC is not responsible for any services
carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
8) Attention is drawn to the normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61788-7 has been prepared by IEC technical committee 90:
Superconductivity.
This third edition cancels and replaces the second edition, published in 2006. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) informative Annex B, relative combined standard uncertainty for surface resistance
measurement has been added;
b) precision and accuracy statements have been converted to uncertainty;
c) reproducibility in surface resistant measurement has been added.

---------------------- Page: 11 ----------------------
SIST EN IEC 61788-7:2020
– 6 – IEC 61788-7:2020 © IEC 2020
The text of this International Standard is based on the following documents:
FDIS Report on voting
90/447/FDIS 90/452/RVD

Full information on the voting for the approval of this International Standard can be found in the
report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 61788 series, published under the general title Superconductivity,
can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the document will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.

---------------------- Page: 12 ----------------------
SIST EN IEC 61788-7:2020
IEC 61788-7:2020 © IEC 2020 – 7 –
INTRODUCTION
Since the discovery of some Perovskite-type Cu-containing oxides, extensive research and
development (R & D) work on high-temperature superconductors (HTS) has been, and is being,
done worldwide, and its application to high-field magnet machines, low-loss power transmission,
electronics and many other technologies is in progress.
In various fields of electronics, especially in telecommunication fields, microwave passive
devices such as filters using HTS are being developed and are undergoing on-site testing
1
[1] [2].
Superconductor materials for microwave resonators [3], filters [4], antennas [5] and delay
lines [6] have the advantage of very low loss characteristics. The parameters of superconductor
materials needed for the design of microwave low loss components are the surface resistance,
(R ) and the temperature dependence of the R . Knowledge of this parameter is of primary
s s
importance for the development of new materials on the supplier side and for the design of
superconductor microwave components on the customer side.
R of high quality HTS films is generally several orders of magnitude lower than that of normal
s
metals [7] [8] [9] [10], which has increased the need for a reliable characterization technique to
measure this property. Traditionally, the R of niobium or any other low-temperature
s
superconducting material was measured by first fabricating an entire three-dimensional
resonant cavity and then measuring its Q-value [11]. The R could be calculated by solving the
s
electro-magnetic field (EM) distribution inside the cavity. Another technique involves placing a
small sample inside a larger cavity. This technique has many forms but usually involves the
uncertainty introduced by extracting the loss contribution due to the HTS films from the
experimentally measured total loss of the cavity.
The best HTS samples are epitaxial films grown on flat crystalline substrates and no high-quality
films have been grown on any curved surface so far. What is needed is a technique that: can
use these small flat samples; requires no sample preparation; does not damage or change the
film; is highly repeatable; has great sensitivity (down to 1/1 000 the R of copper); has great
s
dynamic range (up to the R of copper); can reach high internal powers with only modest input
s
powers; and has broad temperature coverage (4,2 K to 150 K).
The dielectric resonator method is selected among several methods to determine the surface
resistance at microwave frequencies because it is considered to be the most popular and
practical at present. Especially, the sapphire resonator is an excellent tool for measuring
the R of HTS materials [12] [13] [14]
s
The test method given in this document can also be applied to other superconductor bulk plates
materials.
including low T
c
This document is intended to provide an appropriate and agreeable technical base for the time
being to engineers working in the fields of electronics and superconductivity technology.
The test method covered in this document is based on the VAMAS (Versailles Project on
Advanced Materials and Standards) pre-standardization work on the thin film properties of
superconductors.


___________
1
 Numbers in square brackets refer to the bibliography.

---------------------- Page: 13 ----------------------
SIST EN IEC 61788-7:2020
– 8 – IEC 61788-7:2020 © IEC 2020
SUPERCONDUCTIVITY –

Part 7: Electronic characteristic measurements –
Surface resistance of high-temperature
superconductors at microwave frequencies



1 Scope
This part of IEC 61788 describes measurement of the surface resistance (R ) of
s
superconductors at microwave frequencies by the standard two-resonator method. The object
of measurement is the temperature dependence of R at the resonant frequency.
s
The applicable measurement range of R for this method is as follows:
s
– Frequency: 8 GHz < f < 30 GHz
– Measurement resolution: 0,01 mΩ at 10 GHz

2
The R data at the measured frequency, and that scaled to 10 GHz, assuming the f rule for
s
comparison, is reported.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60050-815, International Electrotechnical Vocabulary (IEV) – Part 815: Superconductivity
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-815 apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
4 Requirements
The R of a superconductor film shall be measured by applying a microwave signal to a dielectric
s
resonator with the superconductor film specimen and then measuring the attenuation of the
resonator at each frequency. The frequency shall be swept around the resonant frequency as
the centre, and the 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 less than 20 % for the
measurement temperature range from 20 K to 80 K.

---------------------- Page: 14 ----------------------
SIST EN IEC 61788-7:2020
IEC 61788-7:2020 © IEC 2020 – 9 –
It is the responsibility of the user of this document to establish appropriate safety and health
practices and to determine the applicability of regulatory limitations prior to use.
Hazards exist in this type of measurement. The use of a cryogenic system is essential to cool
the superconductors to 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. The use of an RF generator is also essential to measure high-frequency
properties of materials. If its power is too high, direct contact to human bodies can cause an
immediate burn.
5 Apparatus
5.1 Measurement system
Figure 1 shows a schematic diagram of the system required for the microwave measurement.
The system consists of a network analyzer system for transmission measurement, a
measurement apparatus, and a thermometer for monitoring the measuring temperature
...