Title:
トランスバーサル型フィルタ
Document Type and Number:
Japanese Patent JP4654271
Kind Code:
B2
Abstract:
To provide a transversal type filter having weighted finger electrodes of at least either of an input IDT and an output IDT provided on a piezoelectric substrate, in which a diffraction of elastic wave output from an end face of the weighted IDT electrode is suppressed, a band width is wide, and a high flatness and a high selectivity are realized. In at least either of an input IDT and an output IDT, an apodized region in which a weighting is performed by using an apodizing method with which an aperture of finger electrodes is continuously changed is formed on a center portion of the electrode with respect to a propagation direction of an elastic wave, and dog-leg regions in which a weighting is performed by using a dog-leg method with which the aperture is made into 1/n by floating electrodes to form n tracks are formed on both sides of the apodized region. Subsequently, finger electrodes in each track of the dog-leg region are further weighted by using the apodizing method.
Inventors:
Tadaaki Tsuda
Application Number:
JP2008166431A
Publication Date:
March 16, 2011
Filing Date:
June 25, 2008
Export Citation:
Assignee:
Nippon Denpa Industry Co., Ltd.
International Classes:
H03H9/64; H03H9/145
Domestic Patent References:
| JP3163904A | ||||
| JP2001285014A | ||||
| JP53017133U | ||||
| JP5048373A |
Attorney, Agent or Firm:
Toshio Inoue