GB1512790A - Acoustic surface wave devices - Google Patents

Acoustic surface wave devices

Info

Publication number
GB1512790A
GB1512790A GB3493175A GB3493175A GB1512790A GB 1512790 A GB1512790 A GB 1512790A GB 3493175 A GB3493175 A GB 3493175A GB 3493175 A GB3493175 A GB 3493175A GB 1512790 A GB1512790 A GB 1512790A
Authority
GB
United Kingdom
Prior art keywords
transducers
overlap
transducing means
amplitude
electrodes
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.)
Expired
Application number
GB3493175A
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.)
Philips Components Ltd
Original Assignee
Mullard Ltd
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 Mullard Ltd filed Critical Mullard Ltd
Priority to GB3493175A priority Critical patent/GB1512790A/en
Publication of GB1512790A publication Critical patent/GB1512790A/en
Expired 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
    • H03H9/6489—Compensation of undesirable effects
    • H03H9/6493—Side lobe suppression
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/125—Driving means, e.g. electrodes, coils
    • H03H9/145—Driving means, e.g. electrodes, coils for networks using surface acoustic waves
    • H03H9/14544—Transducers of particular shape or position
    • H03H9/1455—Transducers of particular shape or position constituted of N parallel or series transducers

Landscapes

  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)

Abstract

1512790 Surface wave filters MULLARD Ltd 22 Aug 1975 34931/75 Heading H3U A surface wave band-pass filter comprises first transducing means having one ore more variableoverlap transducers, and second transducing means having two or more interconnected transducers which have responses of uniform amplitude across their apertures and have mutually different amplitude-frequency responses, the combined amplitude-frequency response of the interconnected transducers having a main lobe of band-width substantially equal to that of the first transducing means and side lobes which are attenuated more than the side lobes of a In a first embodiment, Fig. 3, the first transducing means comprises identical variable-overlap output transducers 31, 32, centred on a frequency f 0 , which receive surface waves from respective uniform-overlap input transducers 21, 22 which constitute the second transducing means. Transducers 21, 22 have amplitude-frequency responses centred on slightly different frequencies on either side of f 0 so that a first side lobe of each is suppressed by a second side lobe of the other. More precise cancellation of the side lobes may be achieved by respectively increasing and decreasing the inter-electrode spacings of transducers 21, 22 from their centres towards their ends. In a modification, transducers 21, 22 may be arranged on each side of a single output transducer. The amplitude-frequency responses of input transducers 23, 24 in a second embodiment, Fig. 5, are rendered different (a) by omitting electrodes 5 from one transducer at positions corresponding to existing electrodes in the other input transducer, and (b) by providing in one transducer adjacent short electrodes 5 which do not overlap each other but each overlap an isolated electrode 5<SP>1</SP>. Alternatively adjacent short electrodes may overlap one of two or more isolated electrodes 5' which overlap each other. In modifications the transducers of each transducing means may be connected in series rather than in parallel. Also the aperture of the transducers on one path may differ from that of the transducers on another path.
GB3493175A 1975-08-22 1975-08-22 Acoustic surface wave devices Expired GB1512790A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB3493175A GB1512790A (en) 1975-08-22 1975-08-22 Acoustic surface wave devices

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB3493175A GB1512790A (en) 1975-08-22 1975-08-22 Acoustic surface wave devices

Publications (1)

Publication Number Publication Date
GB1512790A true GB1512790A (en) 1978-06-01

Family

ID=10371700

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3493175A Expired GB1512790A (en) 1975-08-22 1975-08-22 Acoustic surface wave devices

Country Status (1)

Country Link
GB (1) GB1512790A (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2452204A1 (en) * 1979-03-21 1980-10-17 Inst Radiotekh Elektron SURFACE ACOUSTIC WAVE FILTER
EP0322622A2 (en) * 1987-12-30 1989-07-05 Motorola, Inc. Monolithic lattice saw filter
US4878036A (en) * 1986-07-16 1989-10-31 Nihon Musen Kabushiki Kaisha Surface elastic wave filter
EP0367864A1 (en) * 1988-11-11 1990-05-16 Siemens Aktiengesellschaft Surface acoustic wave fibre with variable bandpass characteristics
US5592040A (en) * 1992-08-24 1997-01-07 Nec Corporation Acoustic wave resonator filter
FR2782568A1 (en) * 1998-08-21 2000-02-25 Thomson Csf ACOUSTIC FILTER WITH TWO DIFFERENT CHANNELS WITH REJECTION COMPENSATION
WO2000076067A1 (en) * 1999-06-03 2000-12-14 Matsushita Electric Industrial Co., Ltd. Saw filter
US6650206B2 (en) 2000-09-13 2003-11-18 Matsushita Electric Industrial Co., Ltd. Surface acoustic wave filter and communication apparatus with the same

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2452204A1 (en) * 1979-03-21 1980-10-17 Inst Radiotekh Elektron SURFACE ACOUSTIC WAVE FILTER
US4878036A (en) * 1986-07-16 1989-10-31 Nihon Musen Kabushiki Kaisha Surface elastic wave filter
GB2193060B (en) * 1986-07-16 1991-04-03 Japan Radio Co Ltd Surface elastic wave filter
EP0322622A2 (en) * 1987-12-30 1989-07-05 Motorola, Inc. Monolithic lattice saw filter
EP0322622A3 (en) * 1987-12-30 1990-08-08 Motorola, Inc. Monolithic lattice saw filter
EP0367864A1 (en) * 1988-11-11 1990-05-16 Siemens Aktiengesellschaft Surface acoustic wave fibre with variable bandpass characteristics
US5107234A (en) * 1988-11-11 1992-04-21 Siemens Aktiengesellschaft Surface-wave filter with selectively connectable tracks to provide a variable transmission band
US6437478B1 (en) 1992-08-24 2002-08-20 Nec Corporation Surface acoustic wave resonator filter
US5592040A (en) * 1992-08-24 1997-01-07 Nec Corporation Acoustic wave resonator filter
FR2782568A1 (en) * 1998-08-21 2000-02-25 Thomson Csf ACOUSTIC FILTER WITH TWO DIFFERENT CHANNELS WITH REJECTION COMPENSATION
EP0982859A1 (en) * 1998-08-21 2000-03-01 Thomson-Csf Acoustic filter with two different channels and rejection compensation
US6313717B1 (en) 1998-08-21 2001-11-06 Thomson-Csf Acoustic filter with two different channels with compensation for rejection
SG110996A1 (en) * 1998-08-21 2005-05-30 Thomson Csf Acoustic filter with two different channels with compensation for rejection
KR100698818B1 (en) * 1998-08-21 2007-03-23 탈레스 Acoustic filter with two different channels with compensation for rejection
WO2000076067A1 (en) * 1999-06-03 2000-12-14 Matsushita Electric Industrial Co., Ltd. Saw filter
CN100386965C (en) * 1999-06-03 2008-05-07 松下电器产业株式会社 SAW filter
US6650206B2 (en) 2000-09-13 2003-11-18 Matsushita Electric Industrial Co., Ltd. Surface acoustic wave filter and communication apparatus with the same

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee