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:
Nov. 23, 1982
Filed:
Jun. 17, 1980
Mitsuo Isobe, Moriguchi, JP;
Matsushita Electric Industrial Co., Ltd., Kadoma, JP;
Abstract
An AGC circuit includes an amplitude synchronous detector using a phase-locked loop (PLL), a variable gain amplifier for supplying a signal to this detector, and a means for controlling the amplification degree of the amplifier to make the output signal level constant. More specifically, the AGC circuit includes a first AGC loop including an AGC detector and a low-pass filter provided before the AGC detector, a second AGC loop including a synchronous detector and a phase synchronized state detecting circuit DC coupled to the output end of the synchronous detector, the output signal from the phase synchronized state detecting circuit being used to control the AGC circuit, and a noise eliminating circuit provided at the final stage for adding the output signal from the phase synchronized state detecting circuit and the output signal from the synchronous detector, or for performing subtraction between both the signals.