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. 30, 1986
Filed:
Apr. 26, 1985
Sony Corporation, Tokyo, JP;
Abstract
A demodulating circuit for an amplitude-modulated signal comprises an input terminal to be supplied with an input signal comprising at least a modulated carrier signal amplitude-modulated by an information signal, the modulated carrier signal having a predetermined phase; an oscillator for generating a first demodulating carrier the phase of which is displaced from that of the modulated carrier signal by 90.degree., and a second demodulating carrier which has the same phase as that of the modulated carrier signal; a first synchronous demodulator for demodulating the input signal with the first demodulating carrier; a second synchronous demodulator for demodulating the input signal with the second demodulating carrier; a level detector for detecting the level of a predetermined portion of the demodulated output of the first synchronous detector; a control circuit supplied with the output of the level detector for controlling the oscillator so that the phase of the second demodulating carrier is synchronous with that of the modulated carrier signal; and an output terminal connected to the second synchronous detector for receiving the demodulated information signal from the second synchronous detector. The demodulator circuitry according to the invention performs stable demodulation without using a limiter, and with the phase of the carrier signal for demodulation under its control, thus being free from dependence of the phase of carrier signals for demodulation on the level of input signals.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile