SIST EN 60862-2:2003

SLOVENSKI SIST EN 60862-2:2003

STANDARD
oktober 2003
Surface acoustic wave (SAW) filters of assessed quality - Part 2: Guidance on use
(IEC 60862-2:2002)
ICS 31.160 Referenčna številka
SIST EN 60862-2:2003(en)
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

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EUROPEAN STANDARD EN 60862-2
NORME EUROPÉENNE
EUROPÄISCHE NORM September 2002

ICS 31.140


English version


Surface acoustic wave (SAW) filters of assessed quality
Part 2: Guidance on use
(IEC 60862-2:2002)


Filtres à ondes acoustiques de surface Oberflächenwellenfilter (OFW-Filter)
(OAS) sous assurance de la qualité mit bewerteter Qualität
Partie 2: Guide d'utilisation Teil 2: Leitfaden für die Anwendung
(CEI 60862-2:2002) (IEC 60862-2:2002)






This European Standard was approved by CENELEC on 2002-09-01. 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 Central Secretariat 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 Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,
Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta,
Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels


© 2002 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 60862-2:2002 E

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EN 60862-2:2002 - 2 -
Foreword

The text of document 49/542/FDIS, future edition 2 of IEC 60862-2, prepared by IEC TC 49,
Piezoelectric and dielectric devices for frequency control and selection, was submitted to the
IEC-CENELEC parallel vote and was approved by CENELEC as EN 60862-2 on 2002-09-01.

The following dates were fixed:

– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2003-06-01

– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2005-09-01

Annexes designated "normative" are part of the body of the standard.
In this standard, annex ZA is normative.
Annex ZA has been added by CENELEC.
__________

Endorsement notice

The text of the International Standard IEC 60862-2:2002 was approved by CENELEC as a European
Standard without any modification.
__________

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- 3 - EN 60862-2:2002
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions of any
of these publications apply to this European Standard only when incorporated in it by amendment or
revision. For undated references the latest edition of the publication referred to applies (including
amendments).
NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
Publication Year Title EN/HD Year
IEC 60368-2-1 1988 Piezoelectric filters - -
Part 2: Guide to the use of piezoelectric
filters
Section 1: Quartz crystal filters

IEC 60862 Series Surface acoustic wave (SAW) filters of - -
assessed quality

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NORME CEI
INTERNATIONALE IEC
60862-2
INTERNATIONAL
Deuxième édition
STANDARD
Second edition
2002-05
Filtres à ondes acoustiques de surface (OAS)
sous assurance de la qualité –
Partie 2:
Guide d'utilisation
Surface acoustic wave (SAW) filters
of assessed quality –
Part 2:
Guidance on use
© IEC 2002 Droits de reproduction réservés ⎯ Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in any
utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including
électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from
microfilms, sans l'accord écrit de l'éditeur. the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch  Web: www.iec.ch
CODE PRIX
XA
PRICE CODE
Commission Electrotechnique Internationale
International Electrotechnical Commission
ɆɟɠɞɭɧɚɪɨɞɧɚɹɗɥɟɤɬɪɨɬɟɯɧɢɱɟɫɤɚɹɄɨɦɢɫɫɢɹ
Pour prix, voir catalogue en vigueur
For price, see current catalogue

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60862-2 © IEC:2002 – 3 –
CONTENTS
FOREWORD.7
INTRODUCTION.11
1 Scope.13
2 Normative references .13
3 Terms and definitions .13
3.1 General terms .13
3.2 Response characteristics .19
3.3 SAW filter related terms .27
4 Preliminary remarks of a technical nature .27
5 Fundamentals of SAW transversal filters .29
5.1 Frequency response characteristics .29
5.2 Weighting methods.31
5.3 Filter configurations and their general characteristics .39
6 Fundamentals of SAW resonator filters.67
6.1 Classification of SAW resonator filters.67
6.2 Ladder and lattice filters .67
6.3 Coupled resonator filters .71
6.4 Interdigitated interdigital transducer (lIDT) resonator filters .89
7 Application guide.89
7.1 Substrate materials and their characteristics .89
7.2 Application to electronics circuits.99
7.3 Availability and limitations .101
7.4 Input levels.105
8 Practical remarks .107
8.1 Feed-through signals.107
8.2 Impedance matching condition .109
8.3 Miscellaneous .109
9 Ordering procedure .111
Figure 1 – Frequency response of a SAW filter .31
Figure 2 – Applicable range of frequency and relative bandwidth of the SAW filter and
the other filters .33
Figure 3 – Schematic diagram showing signal flow through a transversal filter.33
Figure 4 – Basic configuration of a SAW transversal filter .35
Figure 5 – Frequency response of the SAW transversal filter shown in figure 4, where
f is the centre frequency and N is the number of finger pairs of the IDT .35
0
Figure 6 – Apodization weighting obtained by apodizing fingers.37
Figure 7 – Withdrawal weighting obtained by selective withdrawal of the fingers.37
Figure 8 – Series weighting obtained by the dog-leg structure .37
Figure 9 – Split-finger (double electrode) configuration .39

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60862-2 © IEC:2002 – 5 –
Figure 10 – Typical characteristics of a SAW IF filter for radio transmission equipment
(nominal frequency of 70,0 MHz) .45
Figure 11 – Typical characteristics of a frequency asymmetrical SAW filter (nominal
frequency of 58,75 MHz for TV-IF use) .47
Figure 12 – SAW three-IDT filter .47
Figure 13 – Typical frequency response of a 900 MHz range SAW filter for
communication (mobile telephone use) .49
Figure 14 – Schematic of the IIDT (multi-IDT) filter.49
Figure 15 – Multi-phase unidirectional transducer .51
Figure 16 – Single-phase unidirectional transducers .53
Figure 17 – Frequency characteristics of a filter using multi-phase unidirectional
transducers.55
Figure 18 – Frequency characteristics of a filter using single-phase unidirectional
transducers.55
Figure 19 – Various reflector filter configurations .59
Figure 20 – Z-path filter configuration .61
Figure 21 – Dual-track reflector filter configuration.61
Figure 22 – SPUDT-based dual-track filter .63
Figure 23 – Frequency characteristics of Z-path filter.63
Figure 24 – Frequency characteristics of dual-track reflector filter.65
Figure 25 – Frequency characteristics of SPUDT-based reflector filter.65
Figure 26 – Structure of ladder and lattice filters.73
Figure 27 – Equivalent circuit of basic section of ladder and lattice filter .75
Figure 28 – Pattern layout of ladder filter .75
Figure 29 – Basic concept of ladder and lattice filter .77
Figure 30 – Typical characteristics of a 1,5 GHz range ladder filter.79
Figure 31 – SAW energy distribution and equivalent circuit of transversely coupled
resonator filter .81
Figure 32 – Typical characteristics of a transversely coupled resonator filter .83
Figure 33 – Basic configuration and SAW energy distribution of longitudinally coupled
resonator filter .85
Figure 34 – Typical characteristics of a longitudinally coupled resonator filter.87
Figure 35 – Schematic of IIDT resonator filter .91
Figure 36 – Frequency characteristics of a 820 MHz range IIDT resonator filter.91
Figure 37 – Minimum theoretical conversion losses for various substrates .93
Figure 38 – Relationship between relative bandwidth and insertion attenuation for
various SAW filters, with the practical SAW filters’ bandwidth for their typical
applications .103
Figure 39 – Ripples in the characteristics of a SAW filter caused by TTE or feed-
through signal: įf = 1/(2t) for the TTE, and įf = 1/t for the feed-through, where t is the
delay of the SAW main signal .105
Table 1 – Properties of typical single-crystal substrate materials .97
Table 2 – Properties of typical thin-film substrate materials.97
Table 3 – Properties of typical ceramic substrate materials.99

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60862-2 © IEC:2002 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SURFACE ACOUSTIC WAVE (SAW) FILTERS
OF ASSESSED QUALITY –
Part 2: Guidance on use
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the 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, the IEC publishes International Standards. 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. The 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 the 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 National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports or guides and they are accepted by the National
Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60862-2 has been prepared by IEC technical committee 49:
Piezoelectric and dielectric devices for frequency control and selection.
This second edition cancels and replaces the first edition published in 1991 and constitutes a
technical revision.
The text of this standard is based on the following documents:
FDIS Report on voting
49/542/FDIS 49/550/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.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 3.

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60862-2 © IEC:2002 – 9 –
IEC 60862 consists of the following parts, under the general title Surface acoustic wave
(SAW) filters of assessed quality
1)
– Part 1: General information, standard values and test conditions
– Part 2: Guidance on use
2)
– Part 3: Standard outlines
– Part 4: Sectional specification – Capability approval (under consideration)
– Part 4-1: Blank detail specification – Capability approval (under consideration)
Future standards in this series will carry the new general title as cited above. Titles of existing
standards in this series will be updated at the time of the next edition.
The committee has decided that the contents of this publication will remain unchanged
until 2007. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
________
1)
A second edition (generic specification) is under consideration.
2)
A second edition is under consideration.

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60862-2 © IEC:2002 – 11 –
INTRODUCTION
This part of IEC 60862 gives practical guidance on the use of SAW filters which are used
in telecommunications, measuring equipment, radar systems and consumer products.
IEC 60862-1 should be referred to for general information, standard values and test
conditions.
The features of these SAW filters are their small size, light weight, adjustment-free, high
stability and high reliability. SAW filters add new features and applications to the field of
crystal filters and ceramic filters. At the beginning, SAW filters meant transversal filters which
have two interdigital transducers (IDT). Although SAW transversal filters have a relatively
higher minimum insertion attenuation, they have excellent amplitude and phase
characteristics. Extensive studies have been made to reduce minimum insertion attenuation,
such as resonator filter configurations, unidirectional interdigital transducers (UDT),
interdigitated interdigital transducers (IIDT). Nowadays, various kinds of SAW filters with low
insertion attenuation are widely used in various applications and SAW filters are available in
the gigahertz range.
This standard has been compiled in response to a generally expressed desire on the part of
both users and manufacturers for guidance on the use of SAW filters, so that the filters may
be used to their best advantage. To this end, general and fundamental characteristics have
been explained here.

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60862-2 © IEC:2002 – 13 –
SURFACE ACOUSTIC WAVE (SAW) FILTERS
OF ASSESSED QUALITY –
Part 2: Guidance on use
1 Scope
SAW filters are now widely used in a variety of applications such as TV, satellite
communications, optical fibre communications, mobile communications and so on. While
these SAW filters have various specifications, many of them can be classified within a few
fundamental categories.
This part of IEC 60862 includes various kinds of filter configuration, of which the operating
frequency range is from approximately 10 MHz to 3 GHz and the relative bandwidth is about
0,02 % to 100 % of the centre frequency.
It is not the aim of this standard to explain theory, nor to attempt to cover all the eventualities
which 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 a SAW filter for a new application. Such a procedure will be the user's insurance
against unsatisfactory performance.
Standard specifications, given in IEC 60862, and national specifications or detail specifi-
cations issued by manufacturers, define the available combinations of nominal frequency,
pass bandwidth, ripple, shape factor, terminating impedance, etc. These specifications are
compiled to include a wide range of SAW filters with standardized performances. It cannot be
over-emphasized that the user should, wherever possible, select his SAW filters from these
specifications, when available, even if it may lead to making small modifications to his circuit
to enable standard filters to be used. This applies particularly to the selection of the nominal
frequency.
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 60368-2-1:1988, Piezoelectric filters – Part 2: Guide to the use of piezoelectric filters –
Section One: Quartz crystal filters
IEC 60862 (all parts), Surface acoustic wave (SAW) filters of assessed quality
3 Terms and definitions
For the purpose of this part of IEC 60862, the following terms and definitions apply.
3.1 General terms
3.1.1
surface acoustic wave (SAW)
acoustic wave, propagating along a surface of an elastic substrate, whose amplitude decays
exponentially with substrate depth

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60862-2 © IEC:2002 – 15 –
3.1.2
surface acoustic wave filter (SAW filter)
filter characterized by a surface acoustic wave which is usually generated by an interdigital
transducer and propagates along a substrate surface to a receiving transducer
3.1.3
power flow vector
vector, analogous to a Poynting vector, characterizing energy propagation caused by a surface
acoustic wave
3.1.4
propagation vector
vector characterizing the phase progression of a wave
3.1.5
power flow angle
angle between the direction of the power flow vector and the direction of the propagation
vector
3.1.6
SAW beam steering
SAW propagation phenomenon in anisotropic materials described by an angle of power flow
which is not zero
3.1.7
SAW diffraction
phenomenon (analogous to diffraction of light from a source of finite aperture) which causes
SAW beam spreading and wavefront distortion
3.1.8
2
SAW coupling coefficient ( k )
s
SAW electromechanical coupling coefficient is defined as follows:
∆ν
s
2
k = 2
s
ν
s
where
∆ν /ν is the relative velocity change produced by short-circuiting the surface potential from
s s
the open-circuit condition
3.1.9
interdigital transducer (IDT)
SAW transducer made of two comb-like conductive structures deposited on a piezoelectric
substrate transforming electrical energy into acoustic energy or vice versa
3.1.10
unidirectional interdigital transducer (UDT)
transducer capable of radiating and receiving surface acoustic waves in or from a single direction
3.1.11
multiphase transducer
interdigital transducer having more than two inputs which are driven in different phases.
Usually used as a unidirectional transducer
3.1.12
finger
element of the IDT comb electrode

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60862-2 © IEC:2002 – 17 –
3.1.13
dummy finger
passive finger which may be included in order to suppress wavefront distortion
3.1.14
split finger
finger formed of more than one element, so as to produce antireflection properties
3.1.15
bus bar
common electrode which connects individual fingers together and also connects the filter to
an external circuit
3.1.16
weighted-response transducer
transducer intended to produce a specified impulse response by design of the structure
(see, for example, 3.1.17 to 3.1.22)
3.1.17
finger overlap or source strength
length of a finger pair between which only electromechanical interaction is generated
3.1.18
apodization
weighting produced by the change of finger overlap over the length of the IDT
3.1.19
withdrawal weighting
weighting by removal of fingers or sources
3.1.20
capacitive weighting
weighting by change of capacitance between electrodes
3.1.21
series weighting
weighting by separation of a finger into individual elements having capacitive coupling
between them. The elements may be separated from the bus bar
3.1.22
phase weighting
weighting by change in period of finger arrangement inside the IDT
3.1.23
aperture
normalized beamwidth of the SAW generated at centre frequency and normalized to the
corresponding wavelength
3.1.24
multistrip coupler (MSC)
array of additional metal strips deposited on a piezoelectric substrate, in a direction
transverse to the propagation direction, which transfers acoustic power from one acoustic
track to an adjacent track

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60862-2 © IEC:2002 – 19 –
3.1.25
reflector
SAW reflecting component which normally makes use of the periodic discontinuity provided by
a metal strip array or a grooved array
3.1.26
spurious reflections
unwanted signals caused by reflection of SAW or bulk waves from substrate edges or
electrodes
3.1.27
triple transit echo (TTE)
unwanted signals in a SAW filter which have traversed three times the propagation path
between input and output IDTs caused by reflections from output and input transducers
3.1.28
bulk-wave signals
unwanted signals caused by bulk-wave excitation, detected at the filter output
3.1.29
feed-through signals (signals of electromagnetic interference)
unwanted signals from the input appearing at the filter output due to stray capacitances and
other electromagnetic couplings
3.1.30
suppression corrugation
grooves in the non-active side of a substrate for suppressing bulk-wave signals
3.1.31
acoustic absorber
material with high acoustic loss placed on any part of the substrate for acoustic absorption
purposes
3.1.32
shielding electrode
electrode intended for the reduction of electromagnetic interference signals
3.1.33
interdigitated interdigital transducer (IIDT)
SAW transducer made of a combination of three or more interdigital transducers. Same as a
multi-IDT
NOTE  In this standard, IIDT (or multi-IDT) resonator filters are referred to as SAW resonator filters composed of a
number of IDTs for input and output in a line alternating with grating reflectors confirming the IDT structure at both
ends.
3.2 Response characteristics
3.2.1
nominal frequency
frequency given by the manufacturer or the specification to identify the filter
3.2.2
centre frequency
arithmetic mean of the cut-off frequencies

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60862-2 © IEC:2002 – 21 –
3.2.3
reference frequency
frequency defined by the specification to which other frequencies may be referred
3.2.4
cut-off frequency
frequency of the pass-band at which the relative attenuation reaches a specified value
3.2.5
total power loss
logarithmic ratio of the available power at the given source to the power that the SAW filter
delivers to a load impedance under specified operating conditions
3.2.6
insertion attenuation
logarithmic ratio of the power delivered directly to the load impedance before insertion of the
filter to the power delivered to the load impedance after insertion of the filter
3.2.7
nominal insertion attenuation
insertion attenuation at a specified reference frequency
3.2.8
relative attenuation
difference between the attenuation at a given frequency and the attenuation at the reference
frequency
3.2.9
pass-band
band of frequencies in which the relative attenuation is equal to, or less than, a specified
value
3.2.10
pass bandwidth
separation of frequencies between which the relative attenuation is equal to, or less than, a
specified value
3.2.11
pass-band ripple
variation in insertion attenuation within a specified pass-band
3.2.12
TTE ripple
maximum variation in attenuation characteristics caused by TTE within a specified pass-band
3.2.13
minimum insertion attenuation
minimum value of insertion attenuation in the pass-band
3.2.14
stop-band
band of frequencies in which the relative attenuation is equal to, or greater than, a specified
value

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