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:
Aug. 04, 2015
Filed:
Jan. 17, 2012
Applicants:
Tomohiko Shibuya, Tokyo, JP;
Atsushi Ajioka, Tokyo, JP;
Atsushi Tsumita, Tokyo, JP;
Inventors:
Assignee:
TDK CORPORATION, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03G 3/20 (2006.01); H03F 1/26 (2006.01); H03F 1/02 (2006.01); H03F 3/19 (2006.01); H03F 3/24 (2006.01); H03F 1/32 (2006.01);
U.S. Cl.
CPC ...
H03F 1/26 (2013.01); H03F 1/0222 (2013.01); H03F 1/3205 (2013.01); H03F 3/19 (2013.01); H03F 3/245 (2013.01); H03F 2200/102 (2013.01);
Abstract
The problem to be solved is to alleviate the distortion characteristic of an amplifier and to prevent the drop in gain with respect to a low-level high-frequency signal. A bias control circuit () for controlling the bias of an amplifier () which amplifies a high-frequency signal is provided herein with a detector () for detecting the envelope of the high-frequency signal, a first bias circuit () for supplying a constant bias current to the amplifier () and a second bias circuit () for supplying a bias current that varies with the variation of the level of the envelope of the high-frequency signal to the amplifier.