Invention Grant
US08736402B2 Elastic wave filter device with IDT electrodes that include a narrower-pitch portion
有权
具有IDT电极的弹性波滤波器装置,其包括窄节距部分
- Patent Title: Elastic wave filter device with IDT electrodes that include a narrower-pitch portion
- Patent Title (中): 具有IDT电极的弹性波滤波器装置,其包括窄节距部分
-
Application No.: US13045587Application Date: 2011-03-11
-
Publication No.: US08736402B2Publication Date: 2014-05-27
- Inventor: Yuichi Takamine
- Applicant: Yuichi Takamine
- Applicant Address: JP Kyoto
- Assignee: Murata Manufacturing Co., Ltd.
- Current Assignee: Murata Manufacturing Co., Ltd.
- Current Assignee Address: JP Kyoto
- Agency: Keating & Bennett, LLP
- Priority: JP2008-244506 20080924
- Main IPC: H03H9/64
- IPC: H03H9/64 ; H03H9/145 ; H03H9/02 ; H03H9/00

Abstract:
An elastic wave filter device having improved sharpness of filter characteristics includes a longitudinally-coupled resonator-type elastic wave filter section including first to third IDT electrodes each including a plurality of electrode fingers, and first and second reflectors. The first to third IDT electrodes include narrower-pitch portions provided in end portions thereof, which are each adjacent to another IDT electrode in a direction of propagation of elastic waves, each of the narrower-pitch portions having a smaller period of electrode fingers than a period of electrode fingers in the remaining portion of the relevant IDT electrode. The number of electrode fingers in the narrower-pitch portion of the second IDT electrode, which is disposed on the side closer to the first IDT electrode, and the number of electrode fingers in the narrower-pitch portion of the second IDT electrode, which is disposed on the side closer to the third IDT electrode, differ from each other.
Public/Granted literature
- US20110156842A1 ELASTIC WAVE FILTER DEVICE Public/Granted day:2011-06-30
Information query