Voltage-controlled oscillator using LC resonator

A voltage-controlled oscillator (VCO) using an LC resonator comprising a first differential amplifier, a second differential amplifier, a LC resonator connected to output of the first and second differential amplifier and a current source which supplies current to the first and second differential amplifier and the LC resonator, the LC resonator comprising:

• a first resonance circuit in which two serially connected varactor diodes and an inductor are connected in parallel;
• a second resonance circuit in which one or more inductor L1 and one or more capacitor C1 are connected in parallel, the second resonance circuit being serially connected to a port of the first resonance circuit;
• and
• a third resonance circuit in which one or more inductor L2 and one or more capacitor C2 are connected in parallel, the third resonance circuit being serially connected to the other port of the first resonance circuit.