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:
Jan. 20, 1976
Filed:
Dec. 01, 1972
Antal Csicsatka, Utica, NY (US);
General Electric Company, Syracuse, NY (US);
Abstract
A broadcast system capable of transmitting and receiving a broadcast signal containing four discrete stereophonically related audio frequency inputs in which there is produced within the transmitter four matrix outputs, each of which is a function of one or more of the inputs. A main carrier wave is then frequency modulated with the first matrix output, with the sidebands of a suppressed first and second subcarrier which has been amplitude modulated with the second and third matrix outputs in quadrature relationship with each other, and with the lower sideband and a relatively small portion of the upper sideband of a depressed third subcarrier that has been amplitude modulated with the fourth matrix output. The modulation of the third subcarrier is limited to a maximum voltage level substantially below the highest level otherwise possible. The first, second, and third subcarriers are regenerated in the receiver and the four matrix outputs are detected. These outputs are then dematrixed to reproduce the four original inputs. The restricted sideband modulation associated with the third subcarrier and the amplitude limiting of its modulation signal maintain the out-of-band radiation of the transmitted energy within acceptable limits.