EP1342317A1 - Filtre a resonateurs a couplage transversal - Google Patents

Filtre a resonateurs a couplage transversal

Info

Publication number
EP1342317A1
EP1342317A1 EP01984707A EP01984707A EP1342317A1 EP 1342317 A1 EP1342317 A1 EP 1342317A1 EP 01984707 A EP01984707 A EP 01984707A EP 01984707 A EP01984707 A EP 01984707A EP 1342317 A1 EP1342317 A1 EP 1342317A1
Authority
EP
European Patent Office
Prior art keywords
resonator
distance
tine
centers
port
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP01984707A
Other languages
German (de)
English (en)
Inventor
Günter Martin
Bert Wall
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tele Filter Zweigniederlassung der Dover Germany GmbH
Original Assignee
Tele Filter Zweigniederlassung der Dover Germany GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tele Filter Zweigniederlassung der Dover Germany GmbH filed Critical Tele Filter Zweigniederlassung der Dover Germany GmbH
Publication of EP1342317A1 publication Critical patent/EP1342317A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/46—Filters
    • H03H9/64—Filters using surface acoustic waves
    • H03H9/6423—Means for obtaining a particular transfer characteristic
    • H03H9/6433—Coupled resonator filters
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/46—Filters
    • H03H9/64—Filters using surface acoustic waves
    • H03H9/6423—Means for obtaining a particular transfer characteristic
    • H03H9/6433—Coupled resonator filters
    • H03H9/644—Coupled resonator filters having two acoustic tracks
    • H03H9/6456—Coupled resonator filters having two acoustic tracks being electrically coupled
    • H03H9/6459—Coupled resonator filters having two acoustic tracks being electrically coupled via one connecting electrode
    • H03H9/6463—Coupled resonator filters having two acoustic tracks being electrically coupled via one connecting electrode the tracks being electrically cascaded
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/46—Filters
    • H03H9/64—Filters using surface acoustic waves
    • H03H9/6423—Means for obtaining a particular transfer characteristic
    • H03H9/643—Means for obtaining a particular transfer characteristic the transfer characteristic being determined by reflective or coupling array characteristics

Definitions

  • the invention relates to the field of electrical engineering / electronics.
  • Objects for which the application is possible and expedient are components based on surface acoustic waves, such as bandpass filters with a relative bandwidth of the order of 0.1 percent and resonators for oscillators.
  • Transversely coupled resonator filters are known in which a plurality of one-port resonator structures are arranged side by side on a piezoelectric substrate, which are composed of two strip reflectors which enclose a flat cavity and whose reflector strips are short-circuited by short-circuit strips, and of an interdigital transducer which is on the flat Cavity is arranged, where in each one-port resonator structure the stripe areas of the stripe reflectors or the tine areas of the interdigital transducers together with the short-circuit stripes or with the collecting electrodes form waveguides for surface acoustic waves and the one-port resonator structures together because of the waveguide effect are coupled.
  • the most common specific embodiment consists of two one-port resonator structures (M. Tanaka, T. Morita, K. Ono and Y. Nakazawa, "narrow bandpass filter using double-mode SAW resonators on quartz", 38 th Annual Frequency Control Symposium 1984, S 286-293 [1])
  • the two converters which are operated as filter inputs and outputs, have a common collecting electrode, which is connected to ground potential, usually two identical filters of this type are connected in a cascade.
  • the invention is based on the object of changing transversely coupled resonator filters on the basis of surface acoustic waves of the known type in such a way that the insertion loss of the filters is reduced in particular by reducing the attenuation due to cascading.
  • This object is achieved according to the invention with the transversely coupled resonator filter described in the claims.
  • the resonator filter according to the invention is characterized in that at least one one-port resonator structure differs from the other one-port resonator structures by the ratio of the tine width to the distance between the tine centers and by the ratio of the width of the reflector strips to the distance between the centers of the reflector strips.
  • the propagation speed of surface acoustic waves depends, among other things, on the ratio of the tine width to the distance between the tine centers and the width of the reflector strips to the distance between the centers of the reflector strips, also called the metallization ratio.
  • the presence of one-port resonator structures with different metallization ratios therefore means that the propagation speeds in the tine and strip gratings of different one-port resonator structures differ from one another.
  • resonator filters can be designed which have a different propagation speed in those one-port resonator structures whose converters are coupling converters than in other one-port resonator structures.
  • Coupling converters are those converters of different filters that are directly connected to one another.
  • the invention can be expediently configured as follows.
  • transducers or strip reflectors of adjacent one-port resonator structures form common collecting electrodes or short-circuit strips.
  • Those one-port resonator structures that differ from the other one-port resonator structures by the ratio of the tine width to the distance between the tine centers and the width of the reflector strips to the distance between the centers of the reflector strips can also differ by the distance between the tine centers and the distance differentiate the middle of the reflector strips.
  • the distance between the tine centers and the distance between the centers of the reflector strips can also be the same in all one-port resonator structures.
  • the number of one-port resonator structures can be two.
  • the aperture of the transducers and reflectors can be the same or different in both one-port resonator structures.
  • the number of one-port resonator structures is particularly expedient to choose the number of one-port resonator structures to be greater than two. This results in the possibility that the one-port resonator structures form two groups, with all converters within a group being connected in parallel with one another and one group representing the input converter and the other group representing the output converter. It is sometimes advantageous if there are gaps between adjacent one-port resonator structures which are filled with reflector strips at the same potential.
  • the transducers in at least one one-port resonator structure can differ from the other transducers by the tine polarity.
  • two identical filters form a filter cascade, in which the same group is used as a coupling converter in both filters, the coupling converter being the group that is connected to a group of the other filter.
  • the group that forms the coupling converter in each case consists of one-port resonator structures with the same tine and reflector strip width and the same gaps between them.
  • the ratio of the tine width to the distance between the tine centers and the width of the reflector strips to the distance between the centers of the reflector strips in the group that forms the coupling converter can be larger or smaller than in all other one-port resonator structures.
  • the drawing shows in principle the design of a transversely coupled resonator filter according to the invention described in more detail in the following embodiment.
  • Two one-port resonator structures 2 and 3 are arranged next to one another on a piezoelectric substrate 1. They contain the reflectors 22 and 23 or 32 and 33 in the same order.
  • the interdigital transducers 21 and 31 are arranged between the reflectors 22 and 23 or 32 and 33.
  • the converter 21 consists of the collecting electrodes 212 and 213 and the tines 211.
  • the converter 31 forms the common collecting electrode 213 with the converter 21 and also consists of the collecting electrode 312 and the tines 311.
  • the reflectors 22 and 23 are made of the reflector strips 221 and 221, respectively 231 and the short-circuit strips 222 and 223 or 232 and 233.
  • the reflectors 32 and 33 form with the reflectors 22 and 23 common short-circuit strips 223 and 233 and are also composed of the reflector strips 321 and 331 and the short-circuit strips 322 and 332, respectively.
  • the center lines of the prongs 211 of the transducer 21 and the prongs 311 of the transducer 31 represent the continuations from one another and form the common center line 215. In an analogous manner, this also applies to the common center line 214.
  • the distance 216 of the common center lines 214 and 215 is accordingly the same in both converters 21 and 31. However, the tines 211 and 311 of the transducers 21 and 31 differ in their width.
  • the center lines of the reflector strips 221 of the strip reflector 22 and the reflector strips 321 of the strip reflector 32 represent the continuations from one another and form the common center line 224. In an analogous manner, this also applies to the common center line 225.
  • the distance 226 of the common center lines 224 and 225 is accordingly the same in both strip reflectors 22 and 32. However, the reflector strips 221 and 321 of the strip reflectors 22 and 32 differ in their width.
  • this description also applies to the strip reflectors 23 and 33 as follows.
  • the center lines of the reflector strips 231 of the strip reflector 23 and the reflector strips 331 of the strip reflector 33 represent the continuations from one another and form the common center line 235.
  • the short-circuit strips 222 and 232, 223 and 233 as well as 322 and 332 of the strip reflectors represent the extension of the collecting electrodes 212, 213 and 312 in the same order.
  • the short-circuit strips 223 and 233 together with the collecting electrode 213 form the coupling strip 4.
  • Each one-port resonator Structure is a waveguide for surface acoustic waves, which guides the waves in the tine and reflector strip area.
  • the coupling strip 4 influences the coupling between the two waveguides.
  • the converter 21 is connected to the filter input 5.
  • the converter 31 is connected to the filter input 6.
  • the reflectors 22, 23, 32 and 33 and the common collecting electrode 213 are connected to the ground potential 7.
  • a filter cascade can be formed from two resonator filters, one of which is shown in the drawing by connecting terminal 6 of the first filter, which is its output, to terminal 6 of the second filter, which is its input.
  • the converter 31 is the coupling converter. Due to the increased effective coupling factor in the coupling converters, the damping of the low-frequency resonance due to cascading is reduced.

Landscapes

  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
  • Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)

Abstract

Filtre à résonateurs à couplage transversal, sur la base d'ondes de surface acoustiques. L'objet de la présente invention est de modifier des filtres à résonateurs comportant plusieurs structures (2 ; 3) de résonateur monoportes placées les unes à côté des autres et constituées de deux réflecteurs à bandes (22 et 23 ; 32 et 33) et d'un transducteur interdigital (21 ; 31), qui forment ensemble un guide d'ondes pour des ondes de surface acoustiques, de manière telle que l'affaiblissement d'insertion des filtres est réduit, en particulier en raison de la réduction de l'affaiblissement due à un montage en cascade. A cet effet, au moins une structure (2 ; 3) de résonateur monoporte se différencie des autres structures de résonateur monoportes par le rapport entre la largeur des dents et l'écart (216) séparant les lignes médianes (214 ; 215) des dents et par le rapport entre la largeur des bandes (221 ; 231 ; 321 ; 331) de réflecteur et l'écart (226 ; 236) séparant les lignes médianes (224 ; 225 et 234 ; 235) des bandes (221 ; 231 ; 321 ; 331) de réflecteur. Le filtre selon la présente invention peut être utilisé en particulier dans des filtres passe-bande d'une largeur de bande relative de l'ordre de 0,1 pour cent et dans des résonateurs pour oscillateurs.
EP01984707A 2000-12-11 2001-12-10 Filtre a resonateurs a couplage transversal Withdrawn EP1342317A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10062847 2000-12-11
DE10062847A DE10062847C1 (de) 2000-12-11 2000-12-11 Transversal gekoppeltes Resonatorfilter
PCT/DE2001/004676 WO2002049212A1 (fr) 2000-12-11 2001-12-10 Filtre a resonateurs a couplage transversal

Publications (1)

Publication Number Publication Date
EP1342317A1 true EP1342317A1 (fr) 2003-09-10

Family

ID=7667483

Family Applications (1)

Application Number Title Priority Date Filing Date
EP01984707A Withdrawn EP1342317A1 (fr) 2000-12-11 2001-12-10 Filtre a resonateurs a couplage transversal

Country Status (6)

Country Link
US (1) US6762534B2 (fr)
EP (1) EP1342317A1 (fr)
JP (1) JP2004516703A (fr)
KR (1) KR100792050B1 (fr)
DE (1) DE10062847C1 (fr)
WO (1) WO2002049212A1 (fr)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7254634B1 (en) * 2002-03-08 2007-08-07 Akamai Technologies, Inc. Managing web tier session state objects in a content delivery network (CDN)
US7569971B2 (en) * 2007-10-02 2009-08-04 Delaware Capital Formation, Inc. Compensation of resonators for substrate and transducer asymmetry
US8258674B2 (en) * 2008-11-03 2012-09-04 Viorel Olariu Surface acoustic wave sensor and system
US8610518B1 (en) 2011-05-18 2013-12-17 Triquint Semiconductor, Inc. Elastic guided wave coupling resonator filter and associated manufacturing
CN104182708B (zh) * 2014-08-11 2017-05-03 东华大学 混合加权型声表面波式单尺度小波变换处理器

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2117992B (en) * 1982-03-24 1985-09-18 Philips Electronic Associated Parallel-series acoustic wave device arrangement
JPH01260911A (ja) * 1988-04-11 1989-10-18 Hitachi Ltd 弾性表面波共振器複合形フィルタ
US5202652A (en) * 1989-10-13 1993-04-13 Hitachi, Ltd. Surface acoustic wave filter device formed on a plurality of piezoelectric substrates
GB2296614B (en) * 1994-12-23 1999-09-15 Advanced Saw Prod Sa Saw filter
JP3360541B2 (ja) * 1995-10-20 2002-12-24 セイコーエプソン株式会社 弾性表面波装置及びその設計方法
DE19744948C2 (de) * 1997-10-10 1999-12-09 Siemens Ag Akustisches Filter, insbesondere Oberflächenwellen-Filter
DE19909470C2 (de) 1999-03-04 2003-09-25 Leibniz Inst Fuer Festkoerper Wandler für akustische Oberflächenwellen

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO0249212A1 *

Also Published As

Publication number Publication date
JP2004516703A (ja) 2004-06-03
US6762534B2 (en) 2004-07-13
DE10062847C1 (de) 2002-05-23
KR100792050B1 (ko) 2008-01-04
WO2002049212A1 (fr) 2002-06-20
US20030011279A1 (en) 2003-01-16
KR20020074512A (ko) 2002-09-30

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