The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 17, 2012
Filed:
Feb. 19, 2008
Atsushi Suwa, Osaka, JP;
Koji Sasabe, Hirakata, JP;
Futoshi Nishimura, Yawata, JP;
Yoshiki Hayasaki, Osaka, JP;
Tomoaki Matsushima, Kizugawa, JP;
Sibei Xiong, Tsukuba, JP;
Takaaki Yoshihara, Osaka, JP;
Norihiro Yamauchi, Shijounawate, JP;
Takeo Shirai, Osaka, JP;
Atsushi Suwa, Osaka, JP;
Koji Sasabe, Hirakata, JP;
Futoshi Nishimura, Yawata, JP;
Yoshiki Hayasaki, Osaka, JP;
Tomoaki Matsushima, Kizugawa, JP;
Sibei Xiong, Tsukuba, JP;
Takaaki Yoshihara, Osaka, JP;
Norihiro Yamauchi, Shijounawate, JP;
Takeo Shirai, Osaka, JP;
Panasonic Electric Works Co., Ltd., Osaka, JP;
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.