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:
Dec. 11, 1979
Filed:
Feb. 13, 1978
Robert L Nelson, Jr, Austin, TX (US);
Tractor, Inc., Austin, TX (US);
Abstract
A digital phase detector includes a hard limiter which transforms an incoming signal of known frequency into a binary signal at the same frequency. A reference generator produces two binary references at the signal frequency, one reference shifted 90.degree. in phase with respect to the other. The binary signal is exclusive-ORed with each reference and the exclusive-OR outputs therefrom control two counters, the counters thereby registering counts analogous to trigonometric functions of the signal phase angle. A phase modulated clock drives the counters, the phase modulation feature permitting a correction factor to be incorporated in order to cancel the error introduced by the quantized nature of the digital computations involved.