Voltage controlled oscillator using tunable active inductor

摘要

A tunable active inductor and a voltage controlled oscillator (VCO) are provided. The tunable active inductor includes a first current source coupled to a power source, a first metal-oxide semiconductor (MOS) transistor including a drain coupled to the first current source and a gate coupled to a first bias voltage, a second MOS transistor including a drain coupled to the power source and a gate coupled to the drain of the first MOS transistor, the gate of the second MOS and the drain of the first MOS being coupled to a second bias voltage, a resonator coupled to a source of the second MOS transistor, and a second current source coupled to the resonator. The VCO employs the tunable active inductor to freely vary the oscillation range of the VCO in a high frequency band.