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:
Feb. 15, 2005
Filed:
Jun. 23, 2003
Yoichi Okubo, Tokyo, JP;
Kiyoshi Funada, Tokyo, JP;
Yasuo Sera, Tokyo, JP;
Masaki Suto, Tokyo, JP;
Masato Horaguchi, Tokyo, JP;
Kazuyoshi Sato, Tokyo, JP;
Toshio Takada, Tokyo, JP;
Tetsuhiko Miyatani, Tokyo, JP;
Naoki Hongo, Tokyo, JP;
Yoichi Okubo, Tokyo, JP;
Kiyoshi Funada, Tokyo, JP;
Yasuo Sera, Tokyo, JP;
Masaki Suto, Tokyo, JP;
Masato Horaguchi, Tokyo, JP;
Kazuyoshi Sato, Tokyo, JP;
Toshio Takada, Tokyo, JP;
Tetsuhiko Miyatani, Tokyo, JP;
Naoki Hongo, Tokyo, JP;
Hitachi Kokusai Electric Inc., Tokyo, JP;
Abstract
A distortion compensator that compensates for distortion arising in a main amplifierthat amplifies a signal effectively compensates for third order distortion which is unbalanced between the higher frequency band and lower frequency band. An amplitude detectordetects the level of a signal subject to amplification and a signal level change direction detection meansdetects the direction of change in the level of the signal. A signal level change control meansstores the correspondence between the signal level and the mode of changing the signal in order to compensate for distortion for when the direction of change in the signal level is positive and when it is negative, and controls a signal change meansso that the amplitude and phase of the signal is changed in a mode of changing the signal corresponding to the detected direction of change in the signal level and the detected signal level. A signal change control content updating meansupdates the content of this correspondence so that the distortion contained in the signal after amplification is reduced.