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:
May. 25, 2004
Filed:
Apr. 25, 2002
Yoichi Okubo, Tokyo, JP;
Kiyoshi Funada, Tokyo, JP;
Masaki Suto, Tokyo, JP;
Masato Horaguchi, Tokyo, JP;
Toshio Takada, Tokyo, JP;
Naoki Hongo, Tokyo, JP;
Hitachi Kokusai Electric Inc., Tokyo, JP;
Abstract
There is provided a distortion canceling circuit for reducing an unbalance between a higher and a lower 3rd order distortion at frequencies of (2·f −f ) and (2·f −f ), respectively, the distortions being generated by an amplifier which amplifies an input signal having at least two frequency components, i.e., f and f . Phase modulation control means supply a control signal, which has a difference frequency of (f −f ), to phase modulation means, the control signal being generated based on the amplified input signal outputted from the amplifier. The phase modulation means performs phase modulation on the amplified input signal based on the supplied control signal to thereby generate a higher and a lower side-band signal having frequencies of (2·f −f ) and (2·f −f ), respectively, each of which has an identical amplitude and a phase difference of 180° with respect to each other. The distortion canceling circuit reduces the unbalance by using the side-band signals.