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:
Feb. 27, 2001

Filed:

Dec. 13, 1999
Applicant:
Inventors:

Gustavo D. Leizerovich, Aventura, FL (US);

Peter J. Yeh, Coral Springs, FL (US);

Assignee:

Motorola, Inc., Schaumburg, IL (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03B 5/12 ; H04B 1/50 ;
U.S. Cl.
CPC ...
H03B 5/12 ; H04B 1/50 ;
Abstract

A dual band VCO selects between the oscillator output frequencies by switching the resonant circuit elements in the active circuit. For each output frequency selected, the oscillator produces a single frequency signal and additional energy in the form of phase noise. This phase noise may be from sideband noise produced by modulation of the single frequency or produced by the active device in the oscillator as flicker noise, or the noise figure of the active device under large signal conditions or the filtering effect or the resonant circuit. Phase noise is reduced by shifting the bias point for the active device to the level where phase noise is minimum for each output frequency. At the time the output frequency is selectively switched, the bias to the active device is selectively switched to an optimum bias level for minimum phase noise for each respective selected frequency.


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