| 摘要 |
A quadrature voltage controlled oscillator with low power and low phase noise characteristic is provided to reduce a phase noise and a flicker noise by using a filer inductor. A quadrature voltage controlled oscillator includes a first delay cell(200) and a second delay cell(300). The first delay cell outputs a first in-phase signal and a second in-phase signal. The second delay cell outputs a first orthogonal phase signal and a second orthogonal phase signal. The first and second delay cells include a resonance circuit(100), first and second complementary transistors(M1,M2), third and fourth complementary transistors(M3,M4), and fifth and sixth transistors(M5,M6) and a filter inductor. The resonance circuit corresponds to the control voltage and controls the frequency of the oscillation signal. The first and second transistors are connected to the one electrode of the resonance circuit in series and maintain the oscillation signal. The third and fourth transistors are connected to the other electrode of the resonance circuit in series and maintain the oscillation signal. The fifth and sixth transistors are connected between the first and second transistors and the power terminal in series and generate the orthogonal phase. The filter inductor is connected between the third and fourth transistors and the ground terminal and reduces the phase noise. |
