JPS6482706A - Surface acoustic wave narrow-band filter - Google Patents

Surface acoustic wave narrow-band filter

Info

Publication number
JPS6482706A
JPS6482706A JP23870287A JP23870287A JPS6482706A JP S6482706 A JPS6482706 A JP S6482706A JP 23870287 A JP23870287 A JP 23870287A JP 23870287 A JP23870287 A JP 23870287A JP S6482706 A JPS6482706 A JP S6482706A
Authority
JP
Japan
Prior art keywords
interdigital electrodes
reflected wave
surface acoustic
input
electrode
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.)
Pending
Application number
JP23870287A
Other languages
Japanese (ja)
Inventor
Takemitsu Takema
Norio Hosaka
Jun Yamada
Takashi Shiba
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.)
Hitachi Ltd
Original Assignee
Hitachi 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 Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP23870287A priority Critical patent/JPS6482706A/en
Publication of JPS6482706A publication Critical patent/JPS6482706A/en
Pending legal-status Critical Current

Links

Landscapes

  • Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)

Abstract

PURPOSE:To reduce the loss and to widen the band by specifying the relation between the center distance between opposite electrode fingers and the wavelength of a surface acoustic wave and the relation between the characteristic impedance discontinuation quantity between the surfaces of an electrode finger part and a no-electrode-finger part and the logarithm of interdigital electrodes for input and output. CONSTITUTION:The peak of an internal reflected wave is made coincident with the reflected wave peak between input and output interdigital electrodes 1 and 2. Namely, an inequality I holds, where (n) is a natural number including 0 and lambda is the wavelength of the surface acoustic wave. Further, when N1 and N2 couples of input and output interdigital electrodes 1 and 2 are provided, let N1 and N2>=n/¦epsilon¦ and N2>=3/2N1, where epsilon is the discontinuation quantity of the characteristic impedance between the surfaces of the electrode finger part and no-electrode-finger part of the interdigital electrodes, and an internal reflected wave is utilized. Consequently, the internal reflected wave peak P1 of the interdigital electrodes 1 and 2 and the reflected wave peak P2 between the input and output interdigital electrodes 1 and 2 are made coincident with each other to reduce the loss and widen the band.
JP23870287A 1987-09-25 1987-09-25 Surface acoustic wave narrow-band filter Pending JPS6482706A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP23870287A JPS6482706A (en) 1987-09-25 1987-09-25 Surface acoustic wave narrow-band filter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP23870287A JPS6482706A (en) 1987-09-25 1987-09-25 Surface acoustic wave narrow-band filter

Publications (1)

Publication Number Publication Date
JPS6482706A true JPS6482706A (en) 1989-03-28

Family

ID=17034018

Family Applications (1)

Application Number Title Priority Date Filing Date
JP23870287A Pending JPS6482706A (en) 1987-09-25 1987-09-25 Surface acoustic wave narrow-band filter

Country Status (1)

Country Link
JP (1) JPS6482706A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02202710A (en) * 1989-01-31 1990-08-10 Nippon Mining Co Ltd Surface acoustic wave resonator filter
JPH03270309A (en) * 1990-03-19 1991-12-02 Fujitsu Ltd Multi-electrode structure type surface acoustic wave element
US5130681A (en) * 1989-06-05 1992-07-14 Hitachi, Ltd. Saw filter and mobile telephone using same

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS50107840A (en) * 1974-01-30 1975-08-25
JPS58127426A (en) * 1982-01-26 1983-07-29 Nec Corp Surface acoustic wave device
JPS58141023A (en) * 1982-02-17 1983-08-22 Nec Corp Surface acoustic wave device
JPS5937724A (en) * 1982-08-26 1984-03-01 Nec Corp Surface acoustic wave resonator type filter
JPS61192112A (en) * 1985-02-20 1986-08-26 Nec Corp Surface acoustic wave device
JPS61281612A (en) * 1985-06-07 1986-12-12 Hitachi Ltd Surface acoustic wave resonator

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS50107840A (en) * 1974-01-30 1975-08-25
JPS58127426A (en) * 1982-01-26 1983-07-29 Nec Corp Surface acoustic wave device
JPS58141023A (en) * 1982-02-17 1983-08-22 Nec Corp Surface acoustic wave device
JPS5937724A (en) * 1982-08-26 1984-03-01 Nec Corp Surface acoustic wave resonator type filter
JPS61192112A (en) * 1985-02-20 1986-08-26 Nec Corp Surface acoustic wave device
JPS61281612A (en) * 1985-06-07 1986-12-12 Hitachi Ltd Surface acoustic wave resonator

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02202710A (en) * 1989-01-31 1990-08-10 Nippon Mining Co Ltd Surface acoustic wave resonator filter
US5130681A (en) * 1989-06-05 1992-07-14 Hitachi, Ltd. Saw filter and mobile telephone using same
JPH03270309A (en) * 1990-03-19 1991-12-02 Fujitsu Ltd Multi-electrode structure type surface acoustic wave element

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