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:
Mar. 16, 2010
Filed:
Mar. 28, 2008
Takeshi Ishigami, Hamura, JP;
Takeshi Ishigami, Hamura, JP;
Hitachi Kokusai Electric Inc., Tokyo, JP;
Abstract
There is disclosed a feedforward amplifier for compensating for distortion produced in an amplifier. The feedforward amplifier controls the phase in a vector adjuster effectively. The feedforward amplifier has a first variable phase shifter PHor PHfor varying the phase of a signal passed through the first variable phase shifter and a second variable phase shifter PHor PHfor varying the signal passed through the first variable phase shifter in either or both of a distortion detection loop for detecting the distortion and a distortion compensation loop for compensating for the distortion. A phase control portion controls the amount of variation in phase in the first variable phase shifter and values of the amount of variation in phase are concentrated toward either one of relatively-larger directions or relatively-smaller directions, the amount of variation in phase in the second phase shifter is controlled according to the concentrated values.