COMPLEMENTARY METAL OXIDE SEMICONDUCTOR VOLTAGE CONTROLLED OSCILLATOR

摘要

A complementary metal oxide semiconductor voltage controlled oscillator is provided. The voltage controlled oscillator includes an LC tank which is supplied with a power supply voltage, the LC tank oscillating at a certain frequency; a negative resistor including first and second N-channel metal oxide semiconductor field effect transistors (NMOS FETs) to sustain the oscillation of the LC tank; a direct current block to remove a direct current component from the power supply voltage; an alternating current block to apply an alternating current voltage to the gates of the first and second NMOS FETs; a first current mirror including third and fourth NMOS FETs and allowing a current to symmetrically flow in the voltage controlled oscillator, a drain and the gate of the third NMOS FET being connected to a reference voltage supply; and the reference voltage supply applying a direct current voltage to the first current mirror.