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:
Apr. 17, 2007
Filed:
Dec. 22, 2004
Applicant:
Hideo Nagata, Ogasa-gun, JP;
Inventor:
Hideo Nagata, Ogasa-gun, JP;
Assignee:
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03F 1/52 (2006.01);
U.S. Cl.
CPC ...
Abstract
A directional coupler is provided on the output side of a power amplifier. An increase in reflected wave power from a load is detected through the directional coupler by an electric power detector (wave detector). Then, a detection signal of an electric power detector is provided to a power amplifier supply voltage control circuit. As a result, the supply voltage supplied to the power amplifier is reduced gradually. By virtue of this, the supply voltage provided to the power amplifier is gradually reduced when the power amplifier approaches a breakdown condition. This protects the power amplifier.