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:
Sep. 22, 2015
Filed:
Jun. 29, 2012
Kimikazu Sano, Tokyo, JP;
Hiroyuki Fukuyama, Tokyo, JP;
Makoto Nakamura, Tokyo, JP;
Hideyuki Nosaka, Tokyo, JP;
Miwa Mutoh, Tokyo, JP;
Koichi Murata, Tokyo, JP;
Kimikazu Sano, Tokyo, JP;
Hiroyuki Fukuyama, Tokyo, JP;
Makoto Nakamura, Tokyo, JP;
Hideyuki Nosaka, Tokyo, JP;
Miwa Mutoh, Tokyo, JP;
Koichi Murata, Tokyo, JP;
NIPPON TELEGRAPH AND TELEPHONE CORPORATION, Tokyo, JP;
Abstract
An automatic gain control circuit () includes a peak detector circuit () that detects the peak voltage of the output signal from a variable gain amplifier (), an average value detection and output amplitude setting circuit () that detects the average voltage of the output signals from the variable gain amplifier () and adds a voltage ½ the desired output amplitude of the variable gain amplifier () to the average voltage, and a high gain amplifier () that amplifies the difference between the output voltage of the peak detector circuit () and the output voltage of the average value detection and output amplitude setting circuit () and controls the gain of the variable gain amplifier () using the amplification result as a gain control signal. The peak detector circuit () includes transistors (Q, Q, Q), a current source (I), and a filter circuit. The filter circuit includes a series connection of a resistor (Ra) and a capacitor (C).