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. 12, 2010
Filed:
Mar. 30, 2007
Shunichi Wakamatsu, Sayama, JP;
Tsuyoshi Shiobara, Sayama, JP;
Naoki Onishi, Sayama, JP;
Nihon Dempa Kogyo Co., Ltd., Tokyo, JP;
Abstract
Provided is a PLL apparatus realizing extremely high frequency stability. As a concrete means for solving the problem, an A/D (analog/digital) conversion unit samples a standard signal based on 40 MHz frequency signal, which is a rectangular wave, from an oven controlled crystal oscillator (OCXO), and an orthogonal transformation unit applies orthogonal transformation to a digital signal from the A/D conversion unit to extract a real part (I) and an imaginary part (Q) which are complex expression of a phase vector equivalent to a phase difference between the standard signal and the frequency signal from the OCXO. An angular velocity of this vector is detected and a direct-current voltage according to the angular velocity is generated and supplied to the OCXO via a PWM control unit.