EN 62810:2015

Cylindrical cavity method to measure the complex permittivity of low-loss dielectric rods

IEC 62810:2015(E) relates to a measurement method for complex permittivity of a dielectric rod at microwave frequency. This method has been developed to evaluate the dielectric properties of low-loss materials in coaxial cables and electronic devices used in microwave systems. It uses the TM010 mode in a circular cylindrical cavity and presents accurate measurement results of a dielectric rod sample, where the effect of sample insertion holes is taken into account accurately on the basis of the rigorous electromagnetic analysis.

Zylindrisches Hohlraumverfahren zur Messung der komplexen Permittivität von verlustarmen dielektrischen Stäben

Mesure de la permitivité complexe des barreaux diélectriques à faibles pertes par la méthode de la cavité cylindrique

L'IEC 62810:2015 traite d’une méthode de mesure de la permittivité complexe d'un barreau diélectrique en hyperfréquence. La présente méthode a été développée pour évaluer les propriétés diélectriques des matériaux à faibles pertes dans les câbles coaxiaux et les dispositifs électroniques utilisés dans les systèmes à hyperfréquences. Elle utilise le mode TM010 dans une cavité cylindrique circulaire et présente des résultats de mesure précis d'un échantillon de barreau diélectrique, pour lequel l'effet des trous d'insertion de l’échantillon est pris en compte avec précision, en se fondant sur l'analyse électromagnétique rigoureuse.

Metoda s valjasto votlino za merjenje kompleksne permitivnosti (dielektrične konstante) nizkoizgubnih dielektričnih palic (IEC 62810:2015)

Ta mednarodni standard se nanaša na metodo za merjenje kompleksne permitivnosti dielektrične palice pri mikrovalovni frekvenci. Ta metoda je bila razvita za oceno dielektričnih lastnosti nizkoizgubnih materialov v koaksialnih kablih in elektronskih napravah, ki se uporabljajo v mikrovalovnih sistemih. Uporablja način TM010 v krožni valjasti votlini in predstavlja točne merilne rezultate vzorca dielektrične palice, pri čemer se učinek vstavitvenih lukenj v vzorcu točno upošteva na podlagi stroge elektromagnetne analize. V primerjavi z običajno metodo iz standarda IEC 60556 [2]1 ima ta metoda naslednje značilnosti:
• vrednosti relativne permitivnosti εr in izgubnega faktorja tanδ vzorca dielektrične palice je mogoče izmeriti točno in neporušitveno;
• merilna točnost je v območju 1,0 % za ε ' in znotraj 20 % za tand;
• učinek vstavitvenih lukenj v vzorcu se popravi z uporabo predstavljenih korekcijskih tabel;
• ta metoda se uporablja za meritve pod naslednjim pogojem:
– frekvenca: 1 GHz ≦ f ≦ 10 GHz;
– relativna permitivnost: 1 ≦ε ' ≦100;
– izgubni faktor: 10–4 ≦tand ≦10–1.

General Information

• Status: Published
• Publication Date: 21-May-2015
• Withdrawal Date: 23-Mar-2018
• ICS: 33.120.30 - RF connectors
• Technical Committee: CLC/SR 46F - RF and microwave passive components
• Drafting Committee: IEC/SC 46F - IEC_SC_46F
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 22-May-2015
• Completion Date: 22-May-2015
• Ref Project: SIST EN 62810:2015 - Cylindrical cavity method to measure the complex permittivity of low-loss dielectric rods (IEC 62810:2015)

Overview

EN 62810:2015 - "Cylindrical cavity method to measure the complex permittivity of low‑loss dielectric rods" (CLC adoption of IEC 62810:2015) defines a microwave measurement method for determining the complex permittivity (ε = ε' − jε") and loss tangent (tanδ) of low‑loss dielectric rods. The standard targets materials used in coaxial cables, RF/microwave passive components and other electronic devices operating at microwave frequencies. The method uses the TM010 resonance of a circular cylindrical cavity and applies rigorous electromagnetic analysis to correct for sample‑insertion holes, delivering non‑destructive and accurate permittivity measurements.

Key topics and requirements

• Measurement method: Resonant cavity technique using the TM010 mode in a circular cylindrical cavity with coaxial coupling.
• Measured parameters: Resonant frequency (f0) and unloaded Q‑factor (Qu) of the cavity with and without the sample; these determine ε' and tanδ.
• Two‑step calculation:
  • Initial perturbation estimates (neglecting insertion holes) to obtain approximate εp and tand_p.
  • Application of numerical correction factors (C1, C2) derived from rigorous electromagnetic analysis (Ritz–Galerkin method) to produce accurate ε' and tanδ.
• Performance & applicability:
  • Frequency range: ~1 GHz to 10 GHz.
  • Relative permittivity range: approximately 1 ≤ ε' ≤ 100.
  • Loss tangent range suitable for low‑loss materials (specified in standard).
  • Typical stated measurement accuracy: ≈1.0% for ε' and ≈20% for tanδ.
• Practical details included: Correction charts/tables for cavity aspect ratios and hole dimensions, measurement procedure (preparation, reference level, cavity parameter measurement, sample measurement), and uncertainty guidance.

Applications

• Material characterization labs measuring dielectric constants and loss for polymers, ceramics, PTFE blends and other rod‑shaped dielectrics.
• Manufacturers of coaxial cables, connectors and microwave passive components requiring dielectric data for design, modelling and quality control.
• R&D teams developing low‑loss substrates and components for radar, telecoms and microwave systems.
• Conformity testing where non‑destructive, accurate permittivity measurement of rod samples is needed.

Who should use this standard

• RF/microwave engineers, materials scientists, test‑laboratory personnel, quality assurance engineers and standards specialists involved in dielectric measurement or component design.

Related standards

• IEC 60556 (conventional dielectric rod/cavity methods) - EN 62810 compares and improves on aspects of the conventional method.
• EN 62810:2015 is the CENELEC/CLC adoption of IEC 62810:2015.

Keywords: EN 62810:2015, cylindrical cavity method, complex permittivity, low‑loss dielectric rods, TM010 mode, loss tangent, resonant cavity, dielectric measurement, microwave frequency.

Standards Content (Sample)

SLOVENSKI STANDARD
01-oktober-2015
0HWRGDVYDOMDVWRYRWOLQR]DPHUMHQMHNRPSOHNVQHSHUPLWLYQRVWLGLHOHNWULþQH
NRQVWDQWHQL]NRL]JXEQLKGLHOHNWULþQLKSDOLF,(&
Cylindrical cavity method to measure the complex permittivity of low-loss dielectric rods
(IEC 62810:2015)
Zylindrisches Hohlraumverfahren zur Messung der komplexen Permittivität von
verlustarmen dielektrischen Stäben (IEC 62810:2015)
Mesure de la permitivité complexe des barreaux diélectriques à faibles pertes par la
méthode de la cavité cylindrique (IEC 62810:2015)
Ta slovenski standard je istoveten z: EN 62810:2015
ICS:
33.120.30 5DGLRIUHNYHQþQLNRQHNWRUML R.F. connectors
5)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 62810
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2015
ICS 33.120.30
English Version
Cylindrical cavity method to measure the complex permittivity of
low-loss dielectric rods
(IEC 62810:2015)
Mesure de la permitivité complexe des barreaux Zylindrisches Hohlraumverfahren zur Messung der
diélectriques à faibles pertes par la méthode komplexen Permittivität von verlustarmen
de la cavité cylindrique dielektrischen Stäben
(IEC 62810:2015) (IEC 62810:2015)
This European Standard was approved by CENELEC on 2015-03-24. 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, 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.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 62810:2015 E
Foreword
The text of document 46F/242/CDV, future edition 1 of IEC 62810, prepared by SC 46F, "R.F. and
microwave passive components", of IEC TC 46, "Cables, wires, waveguides, R.F. connectors, R.F. and
microwave passive components and accessories" was submitted to the IEC-CENELEC parallel vote and
approved by CENELEC as EN 62810:2015.
The following dates are fixed:
(dop) 2015-12-24
• latest date by which the document has
to be implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2018-03-24
standards conflicting with the
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such patent
rights.
Endorsement notice
The text of the International Standard IEC 62810:2015 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 60556 NOTE Harmonised as EN 60556.

IEC 62810 ®
Edition 1.0 2015-02
INTERNATIONAL
STANDARD
colour
inside
Cylindrical cavity method to measure the complex permittivity of low-loss

dielectric rods
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.120.30 ISBN 978-2-8322-2264-5

– 2 – IEC 62810:2015 © IEC 2015

CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Measurement parameters . 5
4 Theory and calculation equations . 5
5 Measurement system . 12
6 Measurement procedure . 14
6.1 Preparation of measurement apparatus. 14
6.2 Measurement of reference level . 14
6.3 Measurement of cavity parameters: σ . 14
r
6.4 Measurement of complex permittivity of test sample: ε', tan d. 15
Annex A (informative) Example of measurement results and accuracy . 16
A.1 Measurement of ε' and tand values . 16
A.2 Measurement uncertainty of ε' and tand . 17
Bibliography . 19

Figure 1 – Structure of a cylindrical cavity resonator . 6
Figure 2 – Correction factor C for ε’. 7
Figure 3 – Correction factor C for tand with the different values of d . 9
2 1
Figure 4 – Schematic diagram of measurement systems . 13
Figure 5 – Resonance frequency f , insertion attenuation IA and half-power band
0 0
width f . 14
BW
Figure 6 – Frequency responses of the TM mode of cylindrical cavity . 15
Table 1 – Numerical values of correction factor C . 8
Table 2 – Numerical values of correction factor C . 10
Table 3 – Numerical values of correction factor C . 11
Table A.1 – The parameters of the cavity and the rod sample . 16
Table A.2 – The resonant frequencies and unloaded Q-factors . 16
Table A.3 – The approximate values and the relative conductivity value . 16
Table A.4 – Correction factors and the measurement results . 16
Table A.5 – The measurement uncertainty of ε’ . 17
Table A.6 – The measurement uncertainty of tand . 18

IEC 62810:2015 © IEC 2015 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
CYLINDRICAL CAVITY METHOD TO MEASURE
THE COMPLEX PERMITTIVITY OF LOW-LOSS DIELECTRIC RODS

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 attestation of conformity. Independent certification bodies provide conformity
assessment services 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 62810 has been prepared by subcommittee 46F: R.F. and
microwave passive components, of IEC technical committee 46: Cables, wires, waveguides,
R.F. connectors, R.F. and microwave passive components and accessories.
The text of this standard is based on the following documents:
CDV Report on voting
46F/242/CDV 46F/260/RVC
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be

– 4 – IEC 62810:2015 © IEC 2015
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

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.
IEC 62810:2015 © IEC 2015 – 5 –
CYLINDRICAL CAVITY METHOD TO MEASURE
THE COMPLEX PERMITTIVITY OF LOW-LOSS DIELECTRIC RODS

1 Scope
This International Standard relates to a measurement method for complex permittivity of a
dielectric rod at microwave frequency. This method has been developed to evaluate the
dielectric properties of low-loss materials in coaxial cables and electronic devices used in
microwave systems. It uses the TM mode in a circular cylindrical cavity and presents
accurate measurement results of a dielectric rod sample, where the effect of sample insertion
holes is taken into account accurately on the basis of the rigorous electromagnetic analysis.
In comparison with the conventional method described in IEC 60556 [2] , this method has the
following characteristics:
• the values of the relative permittivity ε' and loss tangent tand of a dielectric rod sample
can be measured accurately and non-destructively;
• the measurement accuracy is within 1,0 % for ε' and within 20 % for tand;
• the effect of sample insertion holes is corrected using correction charts presented;
• this method is applicable for the measurements on the following condition:
– frequency: 1 GHz ≦f ≦10 GHz;
– relative permittivity: 1 ≦ε' ≦100;
–4 –1
– loss tangent: 10 ≦tand ≦10 .
2 Normative references
Void.
3 Measurement parameters
The measurement parameters are defined as follows:
ε = ε'-jε" (1)
r
tand = ε"/ε' (2)
where ε' and ε" are the real and imaginary parts of the complex relative permittivity ε .
r
4 Theory and calculation equations
A resonator structure used in these measurements is shown in Figure 1. A cavity, made with
copper, with diameter D and height H has sample insertion holes with diameter d and depth g
having ε' and tand is inserted into
oriented coaxially. A dielectric rod sample of diameter d
the holes.
Figures in square brackets refer to the Bibliography.

– 6 – IEC 62810:2015 © IEC 2015
The TM mode, where the electric field component in the cavity is parallel to the sample
rod, is used for the measurement. Taking account of the effect of sample insertion holes
calculated on the basis of the rigorous electromagnetic field analysis, ε' and tand are
determined from the measured values of the resonant frequency f and the unloaded Q-factor
Q . To avoid the tedious numerical calculation and make the measurements easy, the
u
following process is taken in this measurement:
Cylindrical cavity Dielectric rod (sample)
Sample insertion hole
Coaxial cable
with small loop
Ød
Ød
ØD
IEC
Figure 1 – Structure of a cylindrical cavity resonator
The following steps shall be taken:
1) At the first step, obtain approximate values ε and tand from the f and Q values by
p p 0 u
using the simple perturbation formulas, where the effect of sample insertion holes is
neglected. The subscript p denotes the calculated values using the following perturbation
formulas:
1 f − f  D 
0 1
 
ε = +1 (3)
p
 
α f d
1 1
 
   
1 D 1 1
tand =    −  (4)
p
   
2αε d Q Q
p  1   u1 u0 
where α = 1 J ( x ) = 1,855 .
1 01
J ( x) is the Bessel function of order n of first kind and x = 2,405 is the first root of
n 01
J ( x) = 0 . f and Q are the resonant frequency and unloaded Q-factor measured for the
0 u0
cavity without a sample, respectively. f and Q are ones measured for the cavity with a
1 u1
sample.
2) In the second step, obtain accurate values ε' and tand from ε and tand values by using
p p
the following equations with correction factors calculated based on the rigorous analysis:
ε ′ = C ε
(5)
1 p
tand = C tand (6)
2 p
g H g
IEC 62810:2015 © IEC 2015 – 7 –
where correction factors C and C , due to the sample insertion holes and errors included
1 2
in the perturbation formulas, are calculated numerically by using the Ritz-Galerkin method
[3][5], as shown in Figure 2 and Figure 3, and the corresponding data are listed in detail in
Table 1, 2, and 3. The missing data of C and C can be obtained by interpolation or
1 2
extrapolation from the tables. The correction factors shown in these figures are calculated
for the cavity with D = 76,5 mm, H = 20,0 mm, d = 3,0 mm, and g = 10,0 mm, where the
resonant frequency is about 3 GHz. C is also used for a cavity having the same aspect
ratios as H/D, d /D and g/D.
It is found from the analysis for a cavity with insertion holes which constitute a cut-off TM
mode cylindrical waveguide that f converges to a constant value for g>10 mm and d = 3 mm.
0 2
Therefore, the correction factors shown in Figure 2 and Figure 3 are applicable to a dielectric
sample rod with d <3 mm and ε’ below the value c
...