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:
May. 03, 2005
Filed:
Mar. 22, 2002
Yasuyuki Yufu, Tokyo, JP;
Kotaro Takenaga, Tokyo, JP;
Yasuyuki Yufu, Tokyo, JP;
Kotaro Takenaga, Tokyo, JP;
Hitachi Kokusai Electric, Inc., Tokyo, JP;
Abstract
An attenuator of the current invention allows the adjustment in attenuation at a constant impedance level. The attenuator includes at least three variable resistors. Two of the three variable resistors have the substantially same linear resistance characteristics and are controlled in a substantially identical manner. One of the three variable resistors has a non-linear resistance characteristic and is controlled concurrently with the above two variable resistors. As a result of the above resistance characteristics and control, the attenuation is adjusted with respect to the resistance while impedance is maintained at a constant level.