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. 07, 2012
Filed:
Apr. 08, 2011
Suguru Maki, Tokyo, JP;
Suguru Maki, Tokyo, JP;
Mitsubishi Electric Corporation, Tokyo, JP;
Abstract
A power amplifier comprises: an amplifier transistor; a bias circuit supplying bias current to the amplifier transistor; and a collector voltage terminal connected to a collector of the amplifier transistor. The bias circuit includes: a reference voltage terminal into which a reference voltage is input; a power terminal connected to a power source; a transistor having a control terminal connected to the reference voltage terminal, a first terminal connected to the power terminal, and a second terminal that is grounded. The transistor supplies a bias current corresponding to the reference voltage to the amplifier transistor; a variable capacitor connected between the first terminal and a grounding point; and a logic circuit controlling capacitance of the variable capacitor.