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:
Nov. 12, 1996
Filed:
Sep. 19, 1994
Hitachi, Ltd., Tokyo, JP;
Hitachi Tohbu Semiconductor, Ltd., Saitama-ken, JP;
Abstract
A mobile communication apparatus is provided, in which the linearity during a small output power of a radio-frequency power amplifier can be maintained as during a large output power. The input signal power to a radio-frequency power amplifier is decreased by an attenuator during a small power output. The resulting downward trend of the transmission signal power is compensated for by increasing the gain of the radio-frequency amplifier circuit through a transmission power control circuit. Under this condition, the radio-frequency power amplifier is made operable in a linear region of the transistor in the same manner as during a large power output. As a result, the linearity of the amplifier is guaranteed over the whole operating range of the transmission power.