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. 30, 1979
Filed:
Apr. 08, 1976
Gustav Guanella, Zurich, CH;
Patelhold Patentverwertungs- & Holding AG, Glaurus, CH;
Abstract
Method and apparatus for demodulation of a phase shift keyed carrier in which a plurality of auxiliary signal frequency sources are provided and a substantially constant phase difference is maintained therebetween. Each auxiliary signal frequency is mixed with the modulated carrier and the mixer outputs are combined to form the product thereof to yield a control signal for regulating the auxiliary. The sum and differences of the mixer output may be formed prior to forming the product thereof. Input signals to the product forming circuit are amplitude limited to limit variation of the control signal r between -1 .ltoreq.r .ltoreq.+1. A filter may be employed to smooth the control voltage and may be incorporated with switching means to periodically interrupt the control signal to limit evaluation only during the established keying phase.