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:
May. 29, 2007
Filed:
May. 05, 2005
Hisashi Adachi, Mino, JP;
Makoto Sakakura, Uji, JP;
Hisashi Adachi, Mino, JP;
Makoto Sakakura, Uji, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A voltage controlled oscillator, a variable frequency divider, a phase comparator, and a loop filterform a Phase Locked Loop (PLL). A sigma-delta modulatorsigma-delta modulates data obtained by adding a fractional part Mof the frequency division factor data with modulation data X by using an output signal of the variable frequency divideras a clock. An output signal of the sigma-delta modulatoris added to an integral part Mof the frequency division factor data, and the resultant data becomes effective frequency division factor dataof the variable frequency divider. An output signal of the sigma-delta modulatoralso becomes control dataafter passing through a D/A converter, a low-pass filter, and an amplitude adjustment circuit. The control datais inputted into a frequency modulation terminal of the voltage controlled oscillator. Therefore, it is possible to provide a frequency modulator that can use a reference signal source having no frequency modulation function, and perform modulation over a wide range of frequencies based on a digital modulation signal.