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:
Apr. 02, 1985
Filed:
Sep. 30, 1982
Norman W Parker, Wheaton, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A cosine signal corrector circuit as for use in a decoder for a system wherein an information signal is transmitted in the form of one trigonometric transform function of that signal. The second trigonometric transform function signal, required for decoding the information signal, required for decoding the information signal, is obtained by first deriving the Hilbert transform of the transmitted signal and phase inverting it, producing an approximate second transform function signal. The decoder produces the sum of the squares of the two transform function signals, and the difference between that decoder output and 1.0 is an 'error' signal. Under the control of the signum signal of the approximate second transform function signal, the error signal is added to the approximate second transform function signal to produce an accurate second transform function signal. Even if the first transform function signal and its Hilbert transform approach zero at the same time, the circuit provides the correct polarity for the error signal.