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. 10, 2007
Filed:
Feb. 24, 2005
Nobuo Hirose, Hino, JP;
Nobuo Murata, Musashino, JP;
Yasutoshi Tada, Yokosuka, JP;
Nobuo Tsukamoto, Akishima, JP;
Nobuo Hirose, Hino, JP;
Nobuo Murata, Musashino, JP;
Yasutoshi Tada, Yokosuka, JP;
Nobuo Tsukamoto, Akishima, JP;
Hitachi Kokusai Electric, Inc., Tokyo, JP;
Abstract
A distortion compensating circuit for a power amplifier attains raised compensating accuracy with shorter convergence time by accurately and quickly generating a distortion compensation signal for pre-distortion. An error signal representing the difference between the input and output signals of the power amplifier is generated. From the error signal and the input signal, the coefficients of the third-order intermodulation distortion, fifth-order intermodulation distortion and seventh-order intermodulation distortion are calculated. According to these coefficients, a distortion compensating signal which is characteristically opposite in phase and gain to the intermodulation distortions is generated.