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:
Oct. 14, 2008
Filed:
Dec. 22, 2006
Sang-jin Byun, Daejon, KR;
Cheon-soo Kim, Daejon, KR;
Sang-Jin Byun, Daejon, KR;
Cheon-Soo Kim, Daejon, KR;
Electronics and Telecommunications Research Institute, Daejeon, KR;
Abstract
Provided is an Inductor-Capacitor (LC) quadrature Voltage Controlled Oscillator (VCO) having a startup circuit which can accurately select one of +90° and −90° as a phase difference between two clocks generated by the LC quadrature VCO by embodying the startup circuit therein by using a phase detector and a controller. The LC quadrature VCO includes a first LC tank for generating a second clock signal and a fourth clock signal, a second LC tank for generating a first clock signal and a third clock signal, a phase detector for receiving the clock signals from the first LC tank and the second LC tank, and detecting whether a phase difference between the clocks is +90° or −90°, and a controller for discriminating whether phase information detected by the phase detector is equivalent to a phase difference between clocks required by the external signal processing unit, and changing an operation mode of the first LC tank and/or the second LC tank on the basis of the discrimination result of the phase difference between the clocks.