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:
Sep. 06, 1994
Filed:
Sep. 11, 1992
Ronald F McGuire, Rixeyville, VA (US);
Other;
Abstract
The present invention provides an apparatus and method for dual frequency demodulation of frequency shift keyed data signals and linear FM signals. A carrier frequency and first and second side bands are divided and multiplied by first and second local oscillators having different frequencies above and below the carrier frequency. The first oscillator frequency Fx1 is between the lower range F0 of the signal and the carrier frequency FC, and the second oscillator frequency Fx2 is provided between the upper range F1 of the signal and the carrier frequency FC, wherein F0<Fx1<FC<Fx2<F1. The multiplied divided signals are filtered and amplified and converted to either digital data prior to being read by a digital reader, such as a comparator or a conventional differential operational amplifier or linear signals by demodulating FM signals. The invention eliminates the need for intermediate frequency bandpass filters, and uses only low pass filters which can be incorporated into a monolithic integrated circuit as provided by the present invention.