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:
Feb. 22, 2005
Filed:
Oct. 17, 2003
Liang Dai, Carlsbad, CA (US);
Jie Huang, San Diego, CA (US);
Kevin Hsi-huai Wang, San Diego, CA (US);
Hung-chuan Pai, San Diego, CA (US);
Liang Dai, Carlsbad, CA (US);
Jie Huang, San Diego, CA (US);
Kevin Hsi-Huai Wang, San Diego, CA (US);
Hung-Chuan Pai, San Diego, CA (US);
Prominent Communications, Inc., San Diego, CA (US);
Abstract
The voltage-oscillator (VCO) in a frequency synthesizer using a phase-locked loop (PLL) is calibrated during power up or channel switching. The VCO has a coarse frequency control and a fine frequency control. The coarse control consists of digital bits that are used for calibration. The coarse control is connected to the charge pump output as in a regular PLL. By searching for the optimal control setting, the center frequency of the VCO is trimmed close to the desired frequency for the PLL to lock. This allows small VCO gain without losing the tolerance of process and temperature variations. As a result, the PLL phase noise performance is improved.