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:
Aug. 14, 2001
Filed:
Apr. 15, 1999
Tomoya Kaneko, Tokyo, JP;
Makoto Akaishi, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An object of the present invention is to provide an ALC circuit for a transmitter device and its method which are capable of obtaining a detected voltage of sufficient and stable voltage over a wide high-frequency output power range. A signal extracted from a part of a transmission output signal by a directive coupler and a signal obtained by branching and amplifying a part of a local oscillation signal which is inputted to a first mixer for an up-convertor are inputted as a local oscillation signal of a second mixer. After the local oscillation signal has been down-converted into an intermediate frequency signal, it is inputted to a logarithmic amplifier through a band pass filter. The output signal of the logarithmic amplifier is extracted as a detected signal through a diode detector and amplified by a differential amplifier. The variable attenuator is controlled according to the amplified output to obtain a transmission output power.