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. 20, 1996
Filed:
May. 10, 1995
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A power amplifier comprises opposite input and output terminals, a first amplifier circuit connected between the input terminal and the output terminal and comprising a first amplifier FET and a first matching circuit, and a second amplifier circuit connected between the input terminal and the output terminal and comprising a second amplifier FET, a second matching circuit, and a switching circuit. In this power amplifier, the first amplifier circuit outputs an output signal of a first power level when the first amplifier FET is operated while the second amplifier FET is not operated and the switching circuit is turned off, and the second amplifier circuit outputs an output signal of a second power level when the first amplifier FET is not operated while the second amplifier FET is operated and the switching circuit is turned on. Therefore, impedances of the output side matching circuits of the first and second amplifier circuits which output amplified signals of different power levels can be optimized with high precision. As the result, in both the high-power output operation and the low-power output operation, the efficiencies of the first and second amplifier circuits are significantly improved.