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:
Aug. 29, 1978
Filed:
Dec. 13, 1976
William H Giolma, Garland, TX (US);
Bernhard H Andresen, Dallas, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A phase space locked loop system used for performing indirect frequency modulation. A phase locked loop is comprised of a phase detector coupled to a low pass filter coupled to a voltage controlled oscillator with a feedback loop to the phase detector. Input signals provided by a crystal controlled oscillator are fed to the phase detector. A phase difference other than 90.degree. between the voltage controlled oscillator output and the input signal will result in the phase detector generating an error voltage which is filtered by the low pass filter to alter the voltage controlled oscillator until its phase is 90.degree. from the input signal. A modulating signal is injected into the phase locked loop which causes the voltage controlled oscillator to momentarily change frequency until the output of the phase detector changes enough to balance the modulating signal.