Title:
BALANCED SURFACE ACOUSTIC WAVE FILTER DEVICE
Document Type and Number:
WIPO Patent Application WO/2006/068087
Kind Code:
A1
Abstract:
A surface acoustic wave filter device having a balance-unbalance converting function and a high ratio between the impedance of the unbalance terminal and that of the balance terminal. A surface acoustic wave filter section (10) of longitudinally-coupled resonator type is fabricated on a piezoelectric substrate (2) and has first to fifth IDTs (11 to15) arranged in the propagation direction of the surface acoustic wave. The fist, third, and fifth IDTs (11, 13, 15) are connected to an unbalance terminal (3), and the second and fourth IDTs (12, 14) are connected to first and second balance terminals (4, 5), respectively. The second hand fourth IDTs (12, 14) have first and second division IDT sections (12a, 12b, 14a, 14b) divided in the cross width direction. The first and second division IDT sections (12a, 12b, 14a, 14b) are connected in series.
Inventors:
SHIBAHARA TERUHISA (JP)
Application Number:
PCT/JP2005/023261
Publication Date:
June 29, 2006
Filing Date:
December 19, 2005
Export Citation:
Assignee:
MURATA MANUFACTURING CO (JP)
SHIBAHARA TERUHISA (JP)
SHIBAHARA TERUHISA (JP)
International Classes:
H03H9/64; H01L41/09; H01L41/18; H03H9/145
Foreign References:
| JP2003289238A | 2003-10-10 | |||
| JP2004112594A | 2004-04-08 | |||
| JPH03129915A | 1991-06-03 | |||
| JP2002300005A | 2002-10-11 | |||
| JP2004088551A | 2004-03-18 | |||
| JP2004140785A | 2004-05-13 |
Attorney, Agent or Firm:
Miyazaki, Chikara (5-4 Tanimachi 1-chome, Chuo-k, Osaka-shi Osaka 12, JP)
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