IEC 61337-2:2004

IEC 61337-2 ®
Edition 1.0 2004-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Filters using waveguide type dielectric resonators –
Part 2: Guidance for use
Filtres utilisant des résonateurs diélectriques à modes guidés –
Partie 2: Lignes directrices d'utilisation

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé Fax: +41 22 919 03 00
CH-1211 Geneva 20 info@iec.ch
Switzerland www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing more than 30 000 terms and
Technical Specifications, Technical Reports and other definitions in English and French, with equivalent terms in 14
documents. Available for PC, Mac OS, Android Tablets and additional languages. Also known as the International
iPad. Electrotechnical Vocabulary (IEV) online.

IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a More than 55 000 electrotechnical terminology entries in
variety of criteria (reference number, text, technical English and French extracted from the Terms and Definitions
committee,…). It also gives information on projects, replaced clause of IEC publications issued since 2002. Some entries
and withdrawn publications. have been collected from earlier publications of IEC TC 37,

77, 86 and CISPR.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: csc@iec.ch.
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.

Catalogue IEC - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
Application autonome pour consulter tous les renseignements
Le premier dictionnaire en ligne de termes électroniques et
bibliographiques sur les Normes internationales,
électriques. Il contient plus de 30 000 termes et définitions en
Spécifications techniques, Rapports techniques et autres
anglais et en français, ainsi que les termes équivalents dans
documents de l'IEC. Disponible pour PC, Mac OS, tablettes
14 langues additionnelles. Egalement appelé Vocabulaire
Android et iPad.
Electrotechnique International (IEV) en ligne.

Recherche de publications IEC - www.iec.ch/searchpub
Glossaire IEC - std.iec.ch/glossary
Plus de 55 000 entrées terminologiques électrotechniques, en
La recherche avancée permet de trouver des publications IEC
en utilisant différents critères (numéro de référence, texte, anglais et en français, extraites des articles Termes et
comité d’études,…). Elle donne aussi des informations sur les Définitions des publications IEC parues depuis 2002. Plus
projets et les publications remplacées ou retirées. certaines entrées antérieures extraites des publications des

CE 37, 77, 86 et CISPR de l'IEC.
IEC Just Published - webstore.iec.ch/justpublished

Service Clients - webstore.iec.ch/csc
Restez informé sur les nouvelles publications IEC. Just
Published détaille les nouvelles publications parues. Si vous désirez nous donner des commentaires sur cette
Disponible en ligne et aussi une fois par mois par email. publication ou si vous avez des questions contactez-nous:
csc@iec.ch.
IEC 61337-2 ®
Edition 1.0 2004-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Filters using waveguide type dielectric resonators –

Part 2: Guidance for use
Filtres utilisant des résonateurs diélectriques à modes guidés –

Partie 2: Lignes directrices d'utilisation

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX U
ICS 31.140 ISBN 978-2-8322-1337-7

– 2 – 61337-2  IEC:2004
CONTENTS
FOREWORD . 4
INTRODUCTION . 6

1 Scope . 7
2 Normative references . 7
3 Application guide for filters using waveguide type dielectric resonators . 8
3.1 Classification of filters using waveguide type dielectric resonators . 8
3.2 Practical remarks for filters using waveguide type dielectric filters . 9
3.2.1 TE mode dielectric filter . 9
01δ
3.2.2 TM mode dielectric filter . 13
3.2.3 TEM mode coaxial dielectric filter . 15
3.2.4 Chip-type multilayered dielectric filter . 17
3.2.5 Stripline and microstripline dielectric filters . 20
4 Checklist of dielectric resonator specification . 24
4.1 Checklist . 24

Bibliography . 26

Figure 1 – Typical unloaded and maximum operating power of dielectric filters . 9
Q
Figure 2 – Example of practically equivalent unloaded of a TE mode dielectric filter
Q
01δ
compared with a TE mode metal cavity filter . 10
Figure 3 – Example of a TE mode dielectric band-pass filter . 11
01δ
Figure 4 – Example of a TE mode dielectric band-stop filter . 11
01δ
Figure 5 – Example of spurious responses for the TE mode dielectric band-pass filter. 12
01δ
Figure 6 – Example of a TE mode dielectric band-pass filter with quarter wavelength
01δ
coaxial resonators . 12
Figure 7 – TM and TM mode dielectric resonators . 13
010 110
Figure 8 – Example of the third-harmonic distortion level of dielectric resonator material
at 800 MHz . 14
Figure 9 – Example of an antenna filter and an antenna duplexer for cellular base stations 14
Figure 10 – Practically obtained unloaded Q of quarter wavelength TEM mode dielectric
resonators with an ε’ of 20, 40 and 90 (outer diameter = 3 mm; inner diameter = 1 mm;
practical conductivity of shielding conductor = 4,8 × 10 [S/m]) . 16
Figure 11 – Examples of antenna duplexers for portable phones using a TEM mode
dielectric resonator . 16
Figure 12 – Examples of the attenuation characteristics of a block-type duplexer for a
wideband CDMA portable phone . 17
Figure 13 – Example of a chip-type multilayered dielectric band-pass filter . 18
Figure 14 – Example of the attenuation characteristics of a chip-type multilayered
dielectric filter . 19
Figure 15 – Schematic configurations of stripline and microstripline dielectric filter . 20
Figure 16 – Example of the conductor pattern and attenuation characteristic of a
parallel-coupled band-pass stripline filter . 22

61337-2  IEC:2004 – 3 –
Figure 17 – Example of the conductor pattern and attenuation characteristic of an
interdigital band-pass stripline filter . 22
Figure 18 – Example of the conductor pattern and attenuation characteristic of a
comb-line band-pass stripline filter. 23
Figure 19 – Example of the conductor pattern and attenuation characteristic of a
band-stop stripline filter . 23

Table 1 – References to relevant publications . 24

– 4 – 61337-2  IEC:2004
INTERNATIONAL ELECTROTECHNICAL COMMISSION
––––––––––––
FILTERS USING WAVEGUIDE TYPE DIELECTRIC RESONATORS –

Part 2: Guidance for use
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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any equipment
declared to be in conformity with an IEC Publication.
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 61337-2 has been prepared by IEC technical committee 49:
Piezoelectric and dielectric devices for frequency control and selection.
This bilingual version (2014-02) corresponds to the monolingual English version, published in
2004-07.
The text of this standard is based on the following documents:
FDIS Report on voting
49/665/FDIS 49/683/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
The French version of this standard has not been voted upon.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

61337-2  IEC:2004 – 5 –
IEC 61337 consists of the following parts under the general title Filters using waveguide type
dielectric resonators:
Part 1: Generic specification;
Part 1-1: General information, standard values and test conditions – General information and
standard values;
Part 1-2: General information, standard values and test conditions − Test conditions;
Part 2: Guidance for use;
Part 3: Standard outlines .
The committee has decided that the contents of this publication 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 publication 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.

___________
To be published.
To be merged and replaced by IEC 61337-1 in the near future.
Under consideration.
– 6 – 61337-2  IEC:2004
INTRODUCTION
This part of IEC 61337 gives practical guidance on the use of filters using waveguide type
dielectric resonators that are used in telecommunications and radar systems. Refer to
IEC 61337-1-1 and IEC 61337-1-2 for general information, standard values and test conditions.
These dielectric filters have the features of small size, low loss, high reliability and high stability
against temperature and ageing. Dielectric filters are suitable for applications such as mobile
communication service, mobile satellite communication service, microwave terrestrial
communication service, and fixed satellite communication service. In particular, they are now
widely used for duplexers and filters of portable phones and cellular base stations.
This standard has been compiled in response to a generally expressed desire on the part of both
users and manufacturers for guidance for the use of filters using waveguide type dielectric
resonators, so that the filters may be used to their best advantage. For this purpose, general and
fundamental characteristics have been explained in this standard.

61337-2  IEC:2004 – 7 –
FILTERS USING WAVEGUIDE TYPE DIELECTRIC RESONATORS –

Part 2: Guidance for use
1 Scope
The scope of this part of IEC 61337 is limited to filters using waveguide type dielectric
resonators that are used for microwave applications such as portable phones, cellular base
stations and radio links.
It is not the aim of this standard either to explain the theory or to attempt to cover all the
eventualities that may arise in practical circumstances. This standard draws attention to some of
the more fundamental questions which should be considered by the user before he places an
order for dielectric filters for a new application. Such a procedure will be the user's insurance
against unsatisfactory performance.
Standard specifications, such as those given in IEC 61337, and national specifications or detail
specifications issued by manufacturers, will define the available combinations of mid-band
frequency, pass band, insertion attenuation, pass-band ripple, return attenuation, spurious
response, operating power, and so on. These specifications are compiled to include a wide
range of dielectric filters with standardized performances. It cannot be over-emphasized that the
user should, wherever possible, select his dielectric filters from these specifications, when
available, even if it involves making small modifications to his circuit to enable standard filters to
be used.
2 Normative references
The following referenced documents are indispensable for the application 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 60068-1:1988, Environmental testing – Part 1: General and guidance
IEC 60068-2-1:1990, Environmental testing – Part 2: Tests. Tests A – Cold
IEC 60068-2-2:1974, Environmental testing – Part 2: Tests. Tests B – Dry heat
IEC 60068-2-6:1975, Environmental testing – Part 2: Tests. Test Fc: Vibration (sinusoidal)
IEC 60068-2-7:1983, Environmental testing – Part 2: Tests. Test Ga: Acceleration, steady state
IEC 60068-2-13:1983, Environmental testing – Part 2: Tests. Test M: Low air pressure
IEC 60068-2-14:1984, Environmental testing – Part 2: Tests. Test N: Change of temperature
IEC 60068-2-20:1979, Environmental testing – Part 2: Tests. Test T: Soldering
IEC 60068-2-21:1999, Environmental testing – Part 2-21: Tests – Test U: Robustness of
terminations and integral mounting devices

– 8 – 61337-2  IEC:2004
IEC 60068-2-27:1987, Environmental testing – Part 2: Tests. Test Ea and guidance: Shock
IEC 60068-2-30:1980, Environmental testing – Part 2: Tests. Test Db and guidance: Damp heat,
cyclic (12 + 12-hour cycle)
IEC 60068-2-58:1999, Environmental testing – Part 2-58: Tests – Test Td – Test methods for
solderability, resistance to dissolution of metallization and to soldering heat of surface mounting
devices (SMD)
IEC 60068-2-78:2001, Environmental testing – Part 2-78: Tests – Test Cab: Damp heat, steady
state
IEC 61337-1-1, Filters using waveguide type dielectric resonators − Part 1-1: General
information, standard values and test conditions – General information and standard values
IEC 61337-1-2, Filters using waveguide type dielectric resonators – Part 1-2: General
information, standard values and test conditions – Test conditions
3 Application guide for filters using waveguide type dielectric resonators
3.1 Classification of filters using waveguide type dielectric resonators
mode
Filters using waveguide type dielectric resonators are classified into six types: TE
01δ
dielectric filter, TM mode dielectric filter, TEM mode coaxial dielectric filter, stripline and
microstripline dielectric filter, and multilayered chip-type filter.
These dielectric filters are classified according to their operating power and the unloaded Q of
their resonance mode. Figure 1 shows the relationship between the unloaded Q and the
maximum power durability for these filters in practical applications.
High-power durability of up to 100 W is the advantage of dielectric filters. The maximum
operating power, however, should be limited by the construction of filters and by the Q value of
the dielectric resonator used for the filters, because higher operating power causes a
temperature rise that results in inferior electric characteristics such as a shift of mid-band
frequency and an increase in insertion attenuation.

61337-2  IEC:2004 – 9 –
Multi-layered chip-type filter
Stripline and microstripline filter
TM mode filter
TE mode filter
δ
TEM mode
filter
0,1
10 100 1 000 10 000 100 000
Unloaded quality factor (Q)
IEC  850/04
Figure 1 – Typical unloaded and maximum operating power of dielectric filters
Q
3.2 Practical remarks for filters using waveguide type dielectric filters
3.2.1 TE mode dielectric filter
01δ
a) Features of the TE mode dielectric filter
01δ
The TE mode resonator obtains very high unloaded Q , as most of the resonance energy
01δ
is stored in the dielectric element, and the copper loss due to the resistivity of the shielding
conductor is minimized.
Figure 2 shows an example of the practically equivalent unloaded for the TE mode
Q
01δ
dielectric filter compared with the TE mode metal cavity. High unloaded Q from 5 000 to
10 000 is obtained by using high Q dielectric resonator materials with characteristics such
as an ε’ of 30 and a × f value of 150 000 GHz, or an ε’ of 25 and a × f value of
Q Q
300 000 GHz.
Using these TE mode dielectric resonators, miniaturized dielectric filters with low
01δ
insertion attenuation and high temperature stability are realized at the frequency range from
1 GHz to 20 GHz. The relative bandwidth of the TE mode dielectric band-pass filter is
01δ
usually less than 1 % of the mid-band frequency.

Maximum power durability W
– 10 – 61337-2  IEC:2004
Figure 2 – Example of practically equivalent unloaded Q of a TE mode dielectric filter
01δ
compared with a TE mode metal cavity filter
b) Construction of the TE mode dielectric filter
01δ
Figure 3 shows an example of the TE mode dielectric band-pass filter. Plural pieces of
01δ
columnar or cylindrical dielectric resonators are fixed in a metal case.
The dimensions a and b of the filter are determined to constitute the cut-off waveguide of
the dominant TE mode. The adjustment of the mid-band frequency by the trimming screw
is less than 1 % of the mid-band frequency for the dielectric filter, while the adjustment of the
mid-band frequency for the TE mode waveguide filter is 5 %.
Figure 4 shows an example of the TE mode dielectric band-stop filter. The columnar or
01δ
cylindrical dielectric resonators are coupled with the microstrip line. The resonators are fixed
at the three-quarters wavelength interval along the microstrip line.
The high unloaded Q of the dielectric resonators realizes the narrow bandwidth and the low
insertion loss in the neighbouring frequency of the rejection band of the TE mode
01δ
dielectric band-stop filter.
61337-2  IEC:2004 – 11 –
Figure 3 – Example of a TE mode dielectric band-pass filter
01δ
Figure 4 – Example of a TE mode dielectric band-stop filter
01δ
– 12 – 61337-2  IEC:2004
c) Characteristics of the TE mode dielectric filter
01δ
In the case of the TE mode dielectric filter, deterioration of the attenuation characteristics
01δ
are caused by the unnecessary spurious resonances that exist over 1,2 times the mid-band
frequency.
Figure 5 shows an example of the spurious response of the TE mode dielectric band-pass
01δ
filter. This spurious response can be suppressed by using the quarter wavelength coaxial
resonance elements for the first and last resonators of the filter. Figure 6 shows an example
of the filter with the coaxial resonance elements.

Figure 5 – Example of spurious responses for the TE mode dielectric band-pass filter
01δ
Figure 6 – Example of a TE mode dielectric band-pass filter
01δ
with quarter wavelength coaxial resonators

61337-2  IEC:2004 – 13 –
3.2.2 TM mode dielectric filter
a) Features of the TM mode dielectric filter
Figure 7 shows the construction of the TM and the TM mode dielectric resonators.

010 110
These resonators are often used for high-power applications such as filters for cellular base
stations, due to the construction that aids in the release of heat.
As the electric field passes from the bottom to the top of the shielding conductor, undesirable
frequency shift is caused if the air gap arises between the dielectric and the shielding
conductor due to the difference of the thermal-expansion coefficients. To solve this problem,
the practical TM mode resonator and the shielding cavity are made of a mono-block structure
using the same dielectric material. The silver conductor is fired on the surface of this
dielectric cavity. This mono-block structure realizes high temperature stability of the
resonance frequency and high reliability for the release of heat.
The dielectric resonator materials used for the filters of cellular base stations must have low
tanδ to restrain the heat generation and low intermodulation distortion level to restrain the
interference between plural signals.

Figure 7a – TM mode                 Figure 7b – TM mode
010 110
Figure 7 – TM and TM mode dielectric resonators
010 110
– 14 – 61337-2  IEC:2004
The materials with low tanδ have a low third-harmonic distortion level. Figure 8 shows the
third-harmonic distortion level at 800 MHz for three kinds of dielectric resonator materials.
(Zr,Sn)TiO material with an ε’ of 38 and a Q× f value of 50 000 has the low distortion level
of –150 dBc at a field intensity of 50 V/mm, which can be used for filters of cellular base
stations.
b) Construction of the TM mode dielectric filter
Figure 9 shows examples of an antenna filter and an antenna duplexer for cellular base
stations. The antenna filter is made of six TM mode dielectric resonators.

E  V/mm
IEC  858/04
Figure 8 – Example of the third-harmonic distortion level
of dielectric resonator material at 800 MHz

Figure 9a – Antenna filter Figure 9b – Antenna duplexer
Figure 9 – Example of an antenna filter and an antenna duplexer
for cellular base stations
rd
3 harmonic distortion  dBc
61337-2  IEC:2004 – 15 –
The antenna duplexer is composed of six sections Tx filter and Rx filter, each of which is
made of three TM dual-mode dielectric resonators.

One TM dual-mode resonator works as two TM single-mode resonators. The volume of

110 110
this duplexer is one-half of the duplexer using the TM single-mode resonators.

c) Characteristics of the TM mode dielectric filter
The characteristics of the duplexer shown in Figure 9b are 900 MHz of the mid-band
frequency, 100 W of the maximum applied power, and –160 dBc of the third intermodulation
distortion level under the two-tone applied powers, each of which is 30 W. Its dimension is
87 mm × 54 mm × 13 mm.
3.2.3 TEM mode coaxial dielectric filter
a) Features of the TEM mode dielectric filter
Miniaturized dielectric filters using the quarter wavelength TEM mode dielectric resonators
are popularly used for the duplexer of portable phones. They are also used for wireless local
area network systems. These filters have the advantages of low insertion attenuation, high
attenuation characteristics, low frequency drift against temperature and high-power
availability.
The unloaded Q (Q ) of the quarter wavelength TEM mode resonator is given by the
u
following equation:
1 1 1
= + (1)
Q Q Q
u 0 C
where
Q is the quality factor due to the tanδ of the material; and
Q is the quality factor due to the conduction loss of the shielding conductor.
C
Q = 1/ tanδ (2)
ln(b /a)
Q = 2σω μ ⋅ (3)
C 0 0
2 /a+ 2 /b+ (2/L)ln(b /a)
where
σ is the conductivity of the shielding conductor;
a is the outer diameter of the quarter wavelength TEM mode resonator;
b is the inner diameter of the quarter wavelength TEM mode resonator; and
L is the length of the quarter wavelength TEM mode resonator.
As the Q of the quarter wavelength TEM mode resonator is much higher than the Q , its
0 C
unloaded Q is almost determined by Q . The larger a , b and L give a higher Q and
C C
consequently a higher unloaded Q of this resonator. Figure 10 shows practically obtained
unloaded Q as a function of frequency. The resonator with a lower ε’ has a longer length at
the same resonance frequency, which results in the higher unloaded Q .

– 16 – 61337-2  IEC:2004
b) Construction of the TEM mode dielectric filter
Figure 11 shows an example of two types of antenna duplexers for portable phones: the
discrete-type duplexer and the block-type duplexer. These duplexers are surface-mounted
on the circuit-board by the I/O terminals.
The discrete-type duplexer is made of plural TEM mode resonators, which are capacitively or
inductively coupled to each other on a copper-plated resin board.

ε’ = 20
ε’ = 40
ε’ = 90
0,5 2,5
1,0 1,5 2,0
Frequency  GHz
IEC  861/04
Figure 10 – Practically obtained unloaded Q of quarter wavelength TEM mode dielectric
resonators with an ε’ of 20, 40 and 90 (outer diameter = 3 mm; inner diameter = 1 mm;
practical conductivity of shielding conductor = 4,8 × 10 [S/m])

Shielding conductor
Inner conductor
I/O Terminals
Coupling pattern
IEC  863/04
Figure 11a – Discrete-type duplexer Figure 11b – Block-type duplexer
Figure 11 – Examples of antenna duplexers for portable phones
using a TEM mode dielectric resonator
The block-type duplexer is made of a monolithic dielectric block with plural holes. The
interior of the holes and the exterior of the block except the front end are metal-plated. At the
front end, the resonators are capacitively coupled to each other through the patterns of
electrodes.
The block-type duplexer has the advantage of lower height over the discrete-type duplexer,
because metal housing is unnecessary for this duplexer.

Unloaded Q
61337-2  IEC:2004 – 17 –
c) Characteristics of the TEM mode dielectric filter
Figure 12 shows an example of the attenuation characteristics of a block-type duplexer of the
wideband CDMA portable phone. Its insertion attenuations in the Tx and Rx pass-band width
are 1,5 dB and 2,4 dB, respectively, in the temperature range from –35 °C to 85 °C. The
maximum ripples are 1,0 dB in both of the Tx and Rx pass-bandwidths. The dimension of this
duplexer is 12,6 mm × 5,3 mm × 1,9 mm.

Tx
10 5
S21
0 0
-5
-10
-20 -10
-30
-15
-40 -20
S11
-50 -25
-60 -30
Tx.1
ANT.2
-70 -35
Rx.3
-80 -40
-90 -45
1 600 1 700 1 800 1 900 2 000 2 100 2 200 2 300 2 400

Frequency  MHz
IEC  864/04
Rx
10 5
S32
0 0
-10 -5
-20 -10
-30 -15
-40 -20
-50 -25
-60 -30
S22
-70 Tx.1 -35
ANT.2
Rx.3
-80 -40
-90 -45
1 600 1 700 1 800 1 900 2 000 2 100 2 200 2 300 2 400
Frequency  MHz
IEC  865/04
Figure 12 – Examples of the attenuation characteristics of a block-type duplexer
for a wideband CDMA portable phone
3.2.4 Chip-type multilayered dielectric filter

a) Features of the chip-type multilayered dielectric filter
The chip-type multilayered dielectric filter is popularly used in portable phones as a low-pass
filter on the transmitting side to eliminate the spurious responses or as an interstage
band-pass filter on the receiving side.
The advantages of this filter are small size, light weight, and easy handling for the surface
mount device. The disadvantages are the relatively high insertion attenuation due to its low
of around 100, and the limitation of maximum sections, generally three sections,
unloaded Q
due to the inferior adjustment structure of inside electrodes.
Insertion attenuation  dB
Insertion attenuation  dB
Return attenuation  dB
Return attenuation  dB
– 18 – 61337-2  IEC:2004
Inductor
Capacitor
Capacitor
Inductor
I/O terminals
Shielding
conductor
GND terminal
IEC  866/04
Figure 13a – Lumped-element type filter

Shielding
λ/4 stripline resonators
ă
conductor / ‚ S  res onators
Loaded capacitor
I/OI/O tterermmininalals s
Coupling
capacitor
GND terminal
Shielding
Shield electrode
conductor
IEC  867/04
Figure 13b – Distributed-constant type filter

Figure 13 – Example of a chip-type multilayered dielectric band-pass filter

61337-2  IEC:2004 – 19 –
b) Construction of the chip-type multilayered dielectric filter
Figure 13 shows the construction of a chip-type multilayered filter. The conductive patterns
are printed on dielectric sheets and they are stacked and co-fired together.
The chip-type filter is classified into two types. One is called the lumped-element filter that is
made of the L and C conductive patterns. The dielectric materials of this filter generally have
an ε’ of between 7 and 10. The other is called the distributed-constant type filter that is made
of the quarter wavelength stripline resonators. The dielectric materials of this filter has a
higher ε’ of between 20 and 80 to miniaturize the filter.
It is preferable to use the foot pattern recommended by each supplier, which removes the
unmatched impedance or the undesirable stray capacitance and achieves the prescribed
characteristics.
10 1
40 4
60 6
70 7
347 1 347
Frequency  MHz
IEC  868/04
Figure 14a – Attenuation characteristics of an 800 MHz band-pass filter

10 1
1 407 2 407
Frequency  MHz
IEC  869/04
Figure 14b – Attenuation characteristics of a 1,9 GHz band-pass filter

Figure 14 – Example of the attenuation characteristics of a chip-type
multilayered dielectric filter
Insertion attenuation  dB
Insertion attenuation  dB
Insertion attenuation  dB
Insertion attenuation  dB
– 20 – 61337-2  IEC:2004
c) Characteristics of the chip-type multilayered dielectric filter
Figure 14 shows examples of the characteristics for band-pass chip-type filters with
mid-band frequencies of 800 MHz and 1,9 GHz. These filters have an insertion attenuation
of between 1 dB and 2 dB. Their typical dimensions are 4,5 mm × 3,2 mm × 2,0 mm and
2,0 mm × 1,2 mm × 1,0 mm, respectively.
3.2.5 Stripline and microstripline dielectric filters
a) Features of stripline and microstripline dielectric filters
Stripline and microstripline dielectric filters are preferably used in planar and integrated
circuits. They have wide flexibility in designing the strip conductor patterns that realizes the
varieties of transmission characteristics.
These filters cover the frequency range from 300 MHz to 30 GHz and the maximum
operating power up to 10 W. They can also realize the broad pass bandwidth from 5 % to
50 % as a fractional bandwidth, by their close coupling between neighbouring resonators.
Their insertion attenuation, however, is relatively high compared with the TE , TM, and
01δ
TEM mode dielectric filters due to the lower unloaded Q of the stripline and microstripline
resonators.
Figure 15a – Stripline dielectric filter

Figure 15b – Microstripline dielectric filter

Figure 15 – Schematic configurations of stripline
and microstripline dielectric filter

61337-2  IEC:2004 – 21 –
b) Construction of the stripline and microstripline dielectric filters
Figures 15a and 15b show the schematic configuration of the stripline and microstripline
band-pass filters, respectively.
In the case of the stripline filter, the strip conductor patterns are sandwiched between two
layered dielectric substrates. PTFE or low-temperature co-fired ceramics (LTCC) are
commonly used for the dielectric materials. These materials have an ε’ from 2 to 10 and a
relatively low dielectric loss. They can be stacked or co-fired with high-conductivity metals
such as Ag, Cu, or Au.
The distance between the upper and lower outer conductors of this filter is designed to be
short so that the higher order modes could be suppressed over the operating frequency band
including the attenuation band. In addition, the upper and the lower ground conductors are
short-circuited by metal walls or by through-hole rows, which suppress the parallel
waveguide modes.
In the case of the microstripline dielectric filter, the strip conductor patterns are formed on
the front surface of a dielectric substrate by a high-precision photo-etching technique, and a
metal cover is attached in order to reduce the radiation loss and to obtain sharp attenuation
characteristics outside the pass-band.
The width of the metal cover is designed to be less than a half-wavelength of the upper-limit
frequency in the operation band for suppressing the waveguide modes. Materials such as
polytetrafluoroethylene (PTFE) or low-loss alumina ceramics are commonly used for the
substrate. Thinner substrate suppresses the surface radiation mode and an ε’ higher than 5
is desirable to obtain sufficient electric-field concentration in the dielectric substrates.
c) Characteristics of the stripline and microstripline dielectric filters
Figure 16 shows an example of the conductor pattern and attenuation characteristic of a
parallel-coupled stripline band-pass filter. The resonators are made of the half-wavelength
striplines open-circuited at both ends. This filter does not need any adjustment structure as
the long resonator elements have the advantage in the dimensional production dispersion.
In the transmission characteristics, the lowest spurious response appears at 2f where f is
0 0
the mid-band frequency of the first pass band.
Figure 17 shows an example of the conductor pattern and attenuation characteristic of an
interdigital band-pass filter. The resonators are made of quarter wavelength striplines, one
end of which is short-circuited and the other end open-circuited. The lowest spurious
response of this filter appears at 3f .
Figure 18 shows an example of the conductor pattern and attenuation characteristic of a
comb-line band-pass filter. The resonators are made of one-eighth wavelength striplines,
one end of which is short-circuited and the other end loaded with a lumped capacitor. The
lowest spurious response of this filter appears at about 3f and 5f .
0 0
Figure 19 shows an example of the conductor pattern and attenuation characteristic of a
band-stop filter. The resonators are made of stripline resonator stubs, one end of which is
short-circuited and the other capacitively coupled with the main stripline.
The resonance frequency of the resonator stub is adjusted so that the maximum
transmission attenuation is obtained at the mid-band frequency of the stop band.
As practical values, the three-section band-pass filters have an insertion attenuation of
between 0,5 dB and 1,5 dB with a mid-band frequency of 2 GHz and a fractional bandwidth
of 10 %, and the stop-band filter has an insertion attenuation of greater than 50 dB. These
attenuation characteristics are the function of the operating frequency, pass bandwidth,
number of resonators, and unloaded Q of resonators.
The characteristics of microstripline dielectric filters are relatively inferior to those of stripline
dielectric filters, because thinner substrates must be used to suppress the surface radiation
mode. Conductor patterns similar to the stripline filters are used for the microstripline
dielectric filters.
– 22 – 61337-2  IEC:2004
-20
-40
-60
-80
-100
0 2 4 6 8 10
Frequency  GHz
IEC  872/04
Figure 16 – Example of the conductor pattern and attenuation characteristic
of a parallel-coupled band-pass stripline filter

Resonators 0
Main stripline
-20
-40
λ/4
-60
-80
-100
Dielectric substrate
Short-circuited plane
0 2 4 6 8 10
Frequency  GHz
IEC  873/04
Figure 17 – Example of the conductor pattern and attenuation characteristic
of an interdigital band-pass stripline filter

Insertion attenuation  dB Insertion attenuation  dB

61337-2  IEC:2004 – 23 –
-20
-40
-60
-80
-100
0 2 4 6 8 10
Frequency  GHz
IEC  874/04
Figure 18 – Example of the conductor pattern and attenuation characteristic
of a comb-line band-pass stripline filter

0 0
S21(dB)
-10 -10
S11(dB)
-20 -20
-30 -30
-40 -40
-50 -50
-60 -60
-70 -70
-80 -80
1,5 1,75 2,0 2,25 2,5
Frequency  GHz
IEC  875/04
Figure 19 – Example of the conductor pattern and attenuation characteristic
of a band-stop stripline filter

Insertion attenuation  dB
Insertion attenuation  dB
Return attenuation  dB
– 24 – 61337-2  IEC:2004
4 Checklist of dielectric resonator specification
The following checklist provides guidance for the manufacturer to complete specifications for a
particular dielectric filter, including parameters and operating environmental characteristics. It
will also be useful for operation of the filter and for drawing up specifications. The prospective
u
...