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. 03, 2010
Filed:
Dec. 27, 2004
Yuuichi Aoki, Minato-ku, JP;
Yuuichi Aoki, Minato-ku, JP;
NEC Corporation, Tokyo, JP;
Abstract
The present invention provides compensation for distortions in a multi-stage amplifier having a gain expansion characteristic. The present invention also provides an approach for using an amplification stage biased in a state close to B-class, which exhibits high power with added efficiency at low output, in order to have a gain expansion characteristic in all stages of a multi-stage amplifier. The amplifier of the present invention has a gain expansion characteristic which presents an increase in gain in response to an increase in input power or output power in a certain range of the input power or the output power. The amplifier is characterized in that an emitter grounded amplifier circuit comprising a first bipolar transistor has a base terminal to which an input matching circuit and a cathode of a first diode for supplying a bias voltage are connected through a first impedance element which does not block a direct current, and the first diode has an anode which is connected to a reference power supply which presents a sufficiently low impedance at high frequencies.