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.

Date of Patent:
Aug. 23, 2011

Filed:

Nov. 14, 2008
Applicant:

Tzu-cheng Yang, Taipei County, TW;

Inventor:

Tzu-Cheng Yang, Taipei County, TW;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03B 19/00 (2006.01);
U.S. Cl.
CPC ...
Abstract

A frequency synthesizer is provided, including a voltage-controlled oscillator (VCO), a frequency prescaler, a divide-by-2.5 circuit, and a selector. The VCO determine the frequency of a first signal according to an input voltage. The frequency prescaler determines the frequency of a second signal to be the frequency of the first signal divided by 3, 3.5, or 4 according to a first selection signal, and the frequency prescaler also determines the frequency of a third signal to be the frequency of the first signal divided by 6, 7, or 8 according to the first selection signal. The divide-by-2.5 circuit generates a fourth signal, wherein the frequency of the fourth signal is the frequency of the first signal divided by 2.5. The selector selects one of the second signal, the third signal, and the fourth signal as a fifth signal according to a second selection signal.


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