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:
Dec. 03, 2002
Filed:
Dec. 13, 2000
Kazuo Yamashita, Mitaka, JP;
Akira Ito, Mitaka, JP;
Hironori Sakamoto, Mitaka, JP;
Keijiro Ito, Mitaka, JP;
Akira Yamada, Mitaka, JP;
Norihisa Kawasumi, Mitaka, JP;
Japan Radio Co., Ltd., Tokyo, JP;
Abstract
A feed-forward amplifier and a controller thereof. Two types of second pilot signals, sum frequency and difference frequency of a base pilot signal and a local oscillation signal, are generated by an injection-side mixer and injected into a distortion detection loop. Part of a signal appearing at an output terminal is branched, converted in frequency by a detection-side mixer using the local oscillation signal, filtered by a narrow-band filter, input to a synchronizing detector with the filtered output of the filter as error signals, and synchronizing detected with reference to the base pilot signal so as to generate control signals for a distortion rejection loop. The spectrums of the second pilot signals may be spread. A process to cancel the input signal component at the detection side may be performed. A simple circuit configuration enhances the distortion component rejection and suppression effect and shortens the time required until an optimum control state is established.