| 摘要 |
PROBLEM TO BE SOLVED: To provide a four-phase voltage controlled oscillator (VCO) comprising a coupling capacitor. SOLUTION: The four-phase VCO comprises a first delay cell 610 which outputs first and second phase signals with phases different from each other and a second delay cell 630 which outputs third and fourth phase signals being orthogonal to the first and the second phase signals, respectively, and having phases different from each other. The first and the second delay cells comprise: first and second differential VCOs 615, 635; and first and second coupling sections 620, 640 comprising first and second coupling transistors connected to the first and the second differential VCOs, respectively, and first and second coupling capacitors connected in parallel to first, second, third and fourth coupling transistors, respectively, for coupling the phase signals to be output. COPYRIGHT: (C)2008,JPO&INPIT
|
