Differential type voltage controlled oscillator

摘要

A differential type VCO (Voltage Controllable Oscillator) is disclosed. The VCO has a differential amplifier having a couple of transistors and a couple of LC tanks. At each LC tank, a transformer is connected to form a buffer. An oscillating signal is output through the buffer with no power consumption. Additionally, a capacitor is connected to the secondary coil of the transformer to form a bandpass filter, thereby attenuating a harmonic signal included in the oscillating signal.