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:
Oct. 05, 2004
Filed:
Jun. 04, 2003
Takeshi Ishigami, Tokyo, JP;
Yoshinari Nanao, Tokyo, JP;
Hitachi Kokusai Electric Inc., Tokyo, JP;
Abstract
The object of this invention is to provide a feedforward amplifier that performs precise distortion compensation on a plurality of signal groups without adopting broadband frequency-band characteristics for the auxiliary amplifier. This is achieved by inputting a plurality of signal groups, each having a different frequency bandwidth respectively. In a distortion detection loop, a main amplifier is used to amplify this plurality of input signal groups and detect the distortion arising in said main amplifier . In a distortion compensation loop the distortion detected in the distortion detection loop is removed from the amplified signal from said main amplifier At this time, the distortion compensation loop has the same number of distortion amplification systems as the number of input signal groups that use the auxiliary amplifiers and to amplify distortion in each input signal group that contains distortion detected by the distortion detection loop, and that removes the sum total of the distortion of each input signal group amplified by this plurality of distortion amplification systems from the amplified signal from the main amplifier