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. 26, 2008
Filed:
Feb. 17, 2006
Irei Kyu, Kokubunji, JP;
Shigeki Koya, Kokubunji, JP;
Satoshi Tanaka, Kokubunji, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A 90-degree phase delay power divider part PSPD is connected to an input side of a carrier amplifier Ampand a peak amplifier Amp, and a variable electric length power combiner VTLis connected to an output side thereof. A control signal Sig is applied through a control terminal Ctrl of the variable electric length power combiner VTL, and adjustment is performed in correspondence to a carrier frequency band of a carrier signal RFs so that an electric length of the variable electric length power combiner VTLbecomes nearly 90 degrees. As a result, an electric length of an output power combining circuit of a Doherty type amplifier can be made variable, and a power-added efficiency can be enhanced for a multi-band or broad band.