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. 29, 1986
Filed:
Jun. 27, 1984
Robert E Burns, Veradale, WA (US);
Thomas L Grisell, Palo Alto, CA (US);
Fred H Ives, Veradale, WA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A frequency synthesizing apparatus of the closed-loop design employing a first frequency mixing means to provide a continuous constant increment frequency coverage over a given output signal frequency range. The first frequency mixing means is responsive to the output signal and a first reference signal to provide a first difference signal both when the output signal frequency is higher than and lower than the first reference signal frequency. A frequency comparison means is responsive to the first difference signal and to an input signal, the input signal being continuously variable over a given input frequency range, to provide a first error signal for controlling the output frequency and stabilizing the closed loop. The first reference signal is comprising of a plurality of predetermined, selectable frequencies provided by a phase-locked loop employing a second frequency mixing means. The second frequency mixing means is responsive to the first reference signal and a plurality of predetermined, selectable second reference signals to provide a second difference frequency. Phase comparison means responsive to the second difference frequency and to a third reference signal provides a second error signal to control the frequency of the first reference signal and to lock the phase-locked loop when the frequency of the first reference signal frequency is either the sum of the second and third reference signal frequencies or the difference between the second and third reference signal frequencies.