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.

Date of Patent:
Jun. 22, 1999

Filed:

Oct. 30, 1996
Applicant:
Inventors:

Masanori Iwatsuki, Kawasaki, JP;

Shouichi Sato, Sendai, JP;

Kouichi Hayasaka, Sendai, JP;

Yasuhiro Shibuya, Sendai, JP;

Assignee:

Fujitsu Limited, Kanagawa, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
455116 ; 455126 ; 375297 ;
Abstract

Simple and low-cost linearizing circuit for compensating for amplitude and phase distortion produced in a power amplification stage of a radio transmitter apparatus that is required to have a high linearity. Amplitude distortion compensation means, disposed in an intermediate frequency amplifier, has a field-effect transistor whose gate bias voltage is set near to its pinchoff voltage and compensates for amplitude distortion produced in a radio frequency amplifier. On the other hand, phase distortion compensation means having a varactor diode and a branch-line hybrid is disposed in the radio frequency amplifier so as to compensate for phase distortion produced in the radio frequency amplifier. The phase distortion compensation means can be disposed in a local frequency oscillation circuit, alternatively.


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