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:
Jun. 15, 2004
Filed:
Nov. 26, 2002
Takao Moriwaki, Tokyo, JP;
Kousei Maemura, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
Base biases that are supplied to an RF transistor when the RF transistor is in high output power operation and in low output power operation, respectively, are supplied from different voltage sources. When an amplifier is in high output power operation, a base bias is output from a bias circuit unit. At this time, the RF transistor operates at a constant voltage based on the bias that is output from the bias circuit unit. When the amplifier is in low output power operation, a base bias is supplied from a reference voltage terminal via a resistor. This makes it possible to decrease variation in base bias voltage. When the amplifier is in low output power operation, operation of the bias circuit unit is prohibited and hence no current is consumed in the bias circuit unit, whereby efficiency of the amplifier is increased.