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:
Sep. 30, 1997
Filed:
Mar. 28, 1996
Victor S Reinhardt, Rancho Palos Verdes, CA (US);
Hughes Electronics, Los Angeles, CA (US);
Abstract
A frequency synthesizer having two atomic frequency standard inputs that is adapted to provide seamless switching or transition between the atomic frequency standard inputs with no change in the synthesizer output phase and frequency. The synthesizer includes a multichannel phase comparison system, each channel adapted for handling an atomic frequency standard input, a digital phase lock loop, a digital to analog converter, and a voltage controlled crystal oscillator which provides the synthesizer output. The phase comparison system is adapted to continually monitor the integrity of the atomic frequency standard inputs and to continually estimate the phase differences between the two atomic frequency standard inputs. The phase difference is used to estimate the proper phase and frequency offset between the primary and secondary inputs. The programmatically determined phase offset and the fractional frequency offset are then passed to the phase lock loop when switch-over is commanded to produce an output signal that tracks the phase of the original primary input.