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:
Jul. 27, 2004
Filed:
Dec. 04, 2002
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A bias circuit is provided for attenuating harmonic distortions of a signal having a simple construction and which can be applied to a high-frequency amplifier used in a communication device, such as a mobile telephone. The circuit reduces a voltage drop therein and thus provides a high-frequency amplifier having reduced power consumption and an increased operating efficiency. The high-frequency amplifier includes an amplifier circuit, an output matching circuit, and the bias circuit. In the bias circuit, a parallel circuit including a first transmission line and a first capacitor has one end connected between the amplifier and the output matching circuit. The other end of the parallel circuit is connected to a power source and is grounded via a second capacitor. In the circuit, the bias circuit can be short-circuited in a desired frequency band while being an open circuit in a frequency band of a signal to be amplified, hence attenuating the harmonic distortions without using a low pass filter.