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. 12, 1988
Filed:
Oct. 25, 1985
Jerry J Norton, Caney, KS (US);
Martin H Beauford, Bartlesville, OK (US);
Phillips Petroleum Company, Bartlesville, OK (US);
Abstract
A system for transmitting digital data employs an angle modulated carrier signal having constant amplitude and a limited spectrum. The system comprises an offset quadrature phase shift key (QPSK) modulator with a 'tracking filter' phaselocked loop at the output of the QPSK modulator. The phaselocked loop has a voltage controlled oscillator which produces a constant amplitude carrier signal at the output of the loop, and also has a low pass loop filter which reduces the spectrum of the phase modulated carrier signal. Additional spectrum shaping is obtained by connecting L-R-C circuits to the low pass loop filter to eliminate predetermined frequency components from the output of the loop.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile