QUADRATURE VOLTAGE CONTROLLED OSCILLATOR COMPRISING COUPLING CAPACITOR

摘要

A four-phase voltage controlling oscillator having a coupling capacitor is provided to improve the property of phase noises by improving the nonlinear property of a transistor. A four-phase voltage controlling oscillator having a coupling capacitor includes a first delay cell(610) and a second delay cell(630). The first delay cell(610) outputs a first phase signal and a second phase signal having a different phase with each other. The second delay cell(630) outputs a third phase signal and a fourth phase signal having a different phase each other. The first delay cell(610) has a first differential motion voltage controlling oscillator(615) and a first coupling unit(620). The first differential motion voltage controlling oscillator(615) outputs the first phase signal and the second phase signal. The first coupling unit(620) makes the outputted phase signals coupled. The second delay cell(630) has a second differential motion voltage controlling oscillator(635) and a second coupling unit(640). The second differential motion voltage controlling oscillator(635) outputs the third phase signal and the fourth phase signal. The second coupling unit(640) makes the outputted phase signals coupled.