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:
Sep. 03, 2013
Filed:
May. 11, 2010
Kenji Takahashi, Miyagi, JP;
Hidetoshi Yamasaki, Hyogo, JP;
Kenji Takahashi, Miyagi, JP;
Hidetoshi Yamasaki, Hyogo, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A PLL frequency synthesizer provides improved phase noise characteristics. In an ADPLL frequency synthesizer, a frequency characteristic adjusting unit compares a predetermined threshold to the difference between the fractional portion of a DCO control signal and the closest integer value, and generates an adjustment signal. A supplementary varactor shifts the oscillating frequency characteristics based on the adjustment signal. By setting the predetermined threshold to a value defining the range in which the possibility of incrementing or decrementing is high, the oscillating frequency characteristics are shifted in cases when the target value of the fractional portion of the DCO control signal is in the range in which the possibility of incrementing or decrementing is high. By shifting the oscillating frequency characteristics, the target value of the fractional portion of the DCO control signal are shifted to a range in which the possibility of incrementing or decrementing is low.