Wave transmission lines and networks – Coupling networks – Electromechanical filter
Reexamination Certificate
2008-05-06
2008-05-06
Summons, Barbara (Department: 2817)
Wave transmission lines and networks
Coupling networks
Electromechanical filter
C333S195000
Reexamination Certificate
active
07369015
ABSTRACT:
A surface acoustic wave filter includes first to fifth IDTs arranged on a piezoelectric substrate along a surface acoustic wave propagation direction. The second IDT and the fourth IDT have a phase difference of 180° with respect to each other. The second and fourth IDTs are connected to an unbalanced terminal. The third IDT includes a first sub-IDT portion and a second sub-IDT portion. The first IDT and the first sub-IDT portion are connected to a first balanced terminal, and the second sub-IDT portion and the fifth IDT are connected to a second balanced terminal. The following conditions: 1.55≦N3/N1≦2.58 and N1=N5are satisfied, where N1denotes the number of electrode fingers that determines the center frequency of the first IDT, N3denotes the number of electrode fingers that determines the center frequency of the third IDT, and N5denotes the number of electrode fingers that determines the center frequency of the fifth IDT.
REFERENCES:
patent: 5568002 (1996-10-01), Kawakatsu et al.
patent: 5790000 (1998-08-01), Dai et al.
patent: 6268782 (2001-07-01), Hartmann et al.
patent: 6329888 (2001-12-01), Hirota
patent: 6667673 (2003-12-01), Strauss
patent: 6720842 (2004-04-01), Sawada
patent: 6744333 (2004-06-01), Sawada
patent: 6759928 (2004-07-01), Endou et al.
patent: 6762657 (2004-07-01), Takamine
patent: 6781485 (2004-08-01), Takamine et al.
patent: 2004/0066115 (2004-04-01), Takamine
patent: 2004/0080383 (2004-04-01), Takamine
patent: 2004/0080385 (2004-04-01), Takamine et al.
patent: 2005/0212621 (2005-09-01), Takamine
patent: 06-204781 (1994-07-01), None
patent: 11-097966 (1999-04-01), None
patent: 2000-091883 (2000-03-01), None
patent: 2001-308672 (2001-11-01), None
patent: 2001-313540 (2001-11-01), None
patent: 2003-507917 (2003-02-01), None
patent: 2003-179462 (2003-06-01), None
patent: 2004-088551 (2004-03-01), None
patent: 2004-096244 (2004-03-01), None
patent: 01/13514 (2001-02-01), None
patent: 02/03549 (2002-01-01), None
Official Communication for PCT Application No. PCT/JP2005/018754; mailed on Jan. 17, 2006.
Official communication issued in counterpart European Application No. 05793732.8, mailed on Dec. 21, 2007.
Keating & Bennett LLP
Murata Manufacturing Co. Ltd.
Summons Barbara
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