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:
Jul. 10, 1979
Filed:
Aug. 21, 1978
James H Mims, Hanover, MD (US);
Francis W Hopwood, Severna Park, MD (US);
Westinghouse Electric Corp., Pittsburgh, PA (US);
Abstract
A sampling linearizer including a phase shifter for use in improving the accuracy of an FM generated waveform with respect to a desired frequency rate of change is disclosed. The sampling linearizer comprises an oscillator for generating a reference frequency signal; a mixer governed by the generated FM waveform signal and the reference frequency signal to generate a first signal which is sampled at predetermined sampling times; and a linearizing servo controller which is governed by the sampled signal to reduce the inaccuracies in the genereated FM waveform with respect to the desired frequency rate of change. The sampling linearizer further includes a phase shifter disposed between the oscillator and mixer thereof and operative upon the reference frequency signal to generate another signal, the phase shifter being operative to shift the phase of the another signal with respect to the reference frequency signal as governed by a sequence of control signals representative of predetermined phase shift values. Each resulting phase shift causes the first signal to have a common reference value, preferably zero, concurrent with the predetermined sampling times when the frequency rate of change of the generated FM waveform is changing substantially at the desired rate and causes the first signal to have a phase error with respect to the common reference value concurrent with the sampling times when the frequency of the generated FM waveform is not changing substantially at the desired rate. This sampled phase error first signal is representative of the inaccuracies of the generated FM waveform and is used to govern the linearizing servo controller which regulates the FM waveform generator to reduce these frequency inaccuracies and maintain the frequency of the generated FM waveform substantially at the desired rate of change.