GM-BOOSTED DIFFERENTIAL DRAIN-TO-SOURCE FEEDBACK COLPITTS VOLTAGE CONTROLLED OSCILLATOR

摘要

A voltage controlled oscillator outputting a differential signal includes: an inductor connected to a first power supply supplying first voltage; first and second transistors for differential switching; first and second variable capacitors connected to the inductor in parallel; a third transistor of which a gate electrode is connected to a first node; and a fourth transistor of which a gate electrode is connected to a second node. When bias voltage is applied to the gate electrode of the first transistor to be turned on, negative resistance is generated by voltage applied to the first capacitor and the second capacitor through the first transistor. When voltage outputted through the first node is applied to the gate electrode of the third transistor to be turned on, the voltage is additionally applied to the first capacitor and the second capacitor by the third transistor to increase the negative resistance.