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, 2011
Filed:
Feb. 25, 2010
Takayuki Matsuzuka, Tokyo, JP;
Kazuya Yamamoto, Tokyo, JP;
Atsushi Okamura, Tokyo, JP;
Mitsubishi Electric Corporation, Tokyo, JP;
Abstract
A power amplifier and bias circuit includes a combination circuit in which a voltage drive bias circuit and a current drive bias circuit are connected in a parallel relationship with each other. The power amplifier bias circuit also includes an idle current control circuit which uses the collector voltage of amplifier transistors. When the collector voltage of the amplifier transistors is lower than the threshold voltage of a first transistor (approximately 1.3 V), the first transistor is turned off. At that time, since the reference voltage (2.4-2.5 V) is higher than the voltage for turning on both a second transistor and a diode (namely, approximately 1.3 V plus 0.7 V), a current flows and the first transistor turns on. As a result, a current is drawn from the bases of the amplifier transistors to GND through two resistances, so that the idle currents of the amplifier transistors decrease.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile