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:
Oct. 08, 2002
Filed:
Jan. 12, 2001
Satoshi Ichikawa, Tokyo, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A band filter is provided which can freely set the bandwidth and blocking characteristic without any need for a high level designing and adjustment. To this end, a surface acoustic wave device is so constructed as to connect a main filter Fm and sub-filter Fs in a parallel array. Here, relative to a frequency area corresponding to a passband of the main filter Fm the frequency-attenuation amount characteristic of the sub-filter Fs has a blocking band and, relative to a slope portion formed outside a passband of the main filter Fm, the frequency-attenuation characteristic of the sub-filter Fs has a rising area constituting a passband and signals involved provide an opposite-phase relation.