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:
Oct. 05, 1976
Filed:
Feb. 05, 1975
David C Chu, Woodside, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
An automatic transfer oscillator system for frequency measurement using a single sampler is described. Two signals, of frequencies f.sub.1 and f.sub.2, are alternately used to drive the sampler. The two frequencies are sufficiently close by design so that the intermediate frequency signals generated arise from the same harmonic number when sampling a signal of unknown frequency f.sub.x. The resulting average IF output is accurately measured and used to compute the unknown frequency f.sub.x. Accurate measurement of the average IF output is made possible because the transition between f.sub.1 driving the sampler and f.sub.2 driving the sampler only occurs when the two signals are in phase. As a result, the IF signal transitions are also in phase and spurious signals are not produced. This technique is referred to as phase continuous switching.