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:
Jun. 20, 2000
Filed:
Aug. 18, 1998
Hitoshi Ujiie, Aoba-ku, JP;
Advantest Corp., Tokyo, JP;
Abstract
A frequency standard generator for generating a high accuracy reference frequency by synchronizing a high accuracy atomic frequency standard or equivalent thereof and minimizing a phase difference between the generated reference frequency and the received atomic frequency standard. The frequency standard generator includes a voltage controlled crystal oscillator (VCXO) for generating high stability output signal to be used as a standard frequency signal, a radio wave receiver which receives a radio wave and reproduces a time signal to be used as a reference for the VCXO, a time interval measuring circuit which measures a phase difference between the time signal and the output signal of the VCXO and generates data indicating the phase difference, a frequency control processor which produces control data to control the frequency of the VCXO such that the phase difference maintains a constant value through an operation of a phase lock loop, a phase controller which initiates a phase control operation for reducing the phase difference for a predetermined period of time, and a D/A converter which converts the received data to an analog voltage to be supplied to the VCXO.