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. 28, 2003
Filed:
Jul. 11, 2001
Akio Yokoyama, Osaka, JP;
Hisashi Takahashi, Osaka, JP;
Michiyo Yamamoto, Kyoto, JP;
Norihide Kinugasa, Kyoto, JP;
Mamoru Arayashiki, Kanagawa, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
To tune the center frequency of a gm-C filter, which is a bandpass filter with a narrow bandwidth, to a target frequency, only while the filter is being tuned, the original circuit configuration of the filter is replaced with an alternative configuration that realizes a high signal-to-noise ratio. A characteristic tuner generates and inputs an impulse signal, pulse signal or step signal to the filter being tuned and thereby detects and adjusts the center frequency of the filter. And the tuning result is stored on a nonvolatile memory for future reuse. When the filter is operated, the characteristic tuner stops operating to cut down the power dissipation.