Invention Grant
- Patent Title: Bandpass filter and process of fabricating the same
- Patent Title (中): 带通滤波器及其制造工艺
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Application No.: US12528070Application Date: 2008-02-19
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Publication No.: US08098118B2Publication Date: 2012-01-17
- Inventor: Atsushi Suwa , Koji Sasabe , Futoshi Nishimura , Yoshiki Hayasaki , Tomoaki Matsushima , Sibei Xiong , Takaaki Yoshihara , Norihiro Yamauchi , Takeo Shirai
- Applicant: Atsushi Suwa , Koji Sasabe , Futoshi Nishimura , Yoshiki Hayasaki , Tomoaki Matsushima , Sibei Xiong , Takaaki Yoshihara , Norihiro Yamauchi , Takeo Shirai
- Applicant Address: JP Osaka
- Assignee: Panasonic Electric Works Co., Ltd.
- Current Assignee: Panasonic Electric Works Co., Ltd.
- Current Assignee Address: JP Osaka
- Agency: Cheng Law Group, PLLC
- Priority: JP2007-044560 20070223
- International Application: PCT/JP2008/053128 WO 20080219
- International Announcement: WO2008/108193 WO 20080912
- Main IPC: H03H9/46
- IPC: H03H9/46 ; H01P3/08

Abstract:
A bandpass filter includes a combination of a BAW filter and a patterned planar filter with stubs. The BAW filter is composed of a plurality of piezoelectric resonators to give a specific frequency bandpass, while the planer filter is configured to attenuate frequencies near and outside the bandpass. The resonators are connected in a ladder configuration between a first signal transmission path and a ground. The planar filter includes a strip line formed on a dielectric layer to define a second signal transmission path. The BAW filter and the planar filter are formed on a common substrate with the first and second transmission paths connected to each other. The BAW filter, in combination with the patterned planar filter added with the stub, can improve a deep near-band rejection inherent to the BAW filter, exhibiting an excellent out-of-band rejection over certain adjacent frequency ranges outside of the bandpass, and therefore give a sharp and wide bandpass.
Public/Granted literature
- US20100117763A1 BANDPASS FILTER AND PROCESS OF FABRICATING THE SAME Public/Granted day:2010-05-13
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