Title:
FREQUENCY SYNTHESIZER
Document Type and Number:
WIPO Patent Application WO/2011/161860
Kind Code:
A1
Abstract:
Disclosed is a frequency synthesizer, comprising a control circuit (20) that generates a digital control signal; and a Digitally Controlled Oscillator (10) wherein an oscillation frequency changes according to the generated digital control signal. The control circuit (20) further comprises a computation circuit (26) that separates an integer part of a numerical value that represents the phase difference between a reference signal and an oscillation frequency signal of the Digitally Controlled Oscillator into high-order bits and low-order bits, with a redundant bit appended in the most significant bit (MSB) of the latter; and two encoders (21, 22) that respectively encode the high-order bits and the low-order bits and generate control signals. The Digitally Controlled Oscillator (10) further comprises two capacitance element groups (14, 15), the capacitance values whereof are respectively controlled by the control signals. The oscillation frequency changes according to the total capacitance value of the two capacitance element groups.
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Inventors:
OHARA ATSUSHI
YAMASAKI HIDETOSHI
YAMASAKI HIDETOSHI
Application Number:
PCT/JP2011/002215
Publication Date:
December 29, 2011
Filing Date:
April 14, 2011
Export Citation:
Assignee:
PANASONIC CORP (JP)
OHARA ATSUSHI
YAMASAKI HIDETOSHI
OHARA ATSUSHI
YAMASAKI HIDETOSHI
International Classes:
H03L7/099; H03K3/02; H03L7/06; H03L7/093; H03L7/107
Foreign References:
| JP2009010599A | 2009-01-15 |
Other References:
PAO-LUNG CHEN ET AL.: "A portable digitally controlled oscillator using novel varactors", IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II: EXPRESS BRIEFS, vol. 52, no. 5, May 2005 (2005-05-01), pages 233 - 237
Attorney, Agent or Firm:
MAEDA, Hiroshi et al. (JP)
Hiroshi Maeda (JP)
Hiroshi Maeda (JP)
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Claims:
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