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:
Dec. 31, 2002
Filed:
Oct. 26, 2000
Ting-Yuan Cheng, Hsinchu, TW;
Abstract
The analog phase frequency detecting apparatus includes the devices described below. The first frequency sensitive device is used to amplify a first input signal with a gain function, which changes responding to the frequency of the reference input signal. The transfer characteristic curve of the first frequency sensitive device includes a monotonous decrease (or increase) curve. The second frequency sensitive device is utilized to amplify an oscillating signal with the varying gain function responding to the frequency of the oscillating signal. The first and the second DC component extracting device is used to extract the direct current component of the first and the second amplified input signal. The comparing device is used to generate a frequency locking signal, in addition, the phase detecting device generates a phase locking signal when the phase of the reference input signal is equal to that of the oscillating signal. The loop filter generates a voltage level responding to the frequency locking signal and the phase locking signal. Then the voltage controlled oscillator generates the output signal that has the same frequency and constant phase relationship as that of the reference input signal responding to the frequency locking signal and the phase locking signal.