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:
May. 04, 1976
Filed:
Mar. 06, 1975
Varn Richard Frank, Miamisburg, OH (US);
Ronald Eugene Wysong, Centerville, OH (US);
Michael David Valentine, Cincinnati, OH (US);
R. L. Drake Company, Miamisburg, OH (US);
Abstract
A single-sideband radiotelephone system includes a single-sideband transmitter which initially broadcasts two frequency-spaced tones simultaneously for a predetermined time interval, and thereafter broadcasts the two tones alternately in a unique code pattern to access a predetermined receiver. Each single-sideband receiver in the system includes a pair of detectors each having a narrow bandpass, the center frequencies of which are spaced apart by the difference in frequency of the transmitted tones. The center frequencies of the detectors are simultaneously varied relative to the initial two-tone broadcast while maintaining the frequency differential therebetween; and simultaneous detection of both tones will terminate the frequency varying mode of operation. The subsequently transmitted unique code pattern is then sensed by the detectors, the code pattern decoded, and the selected receiver is enabled to receive any subsequently broadcasted information.