Low noise amplifier using varator diode and method of driving the same

PURPOSE: A low noise amplifier using a variable capacitance diode and a driving method thereof are provided to perform continuous input impedance matching according to a variable voltage using the variable capacitance diode. CONSTITUTION: A first transistor(M1) includes a gate terminal connected to an input terminal. A source terminal of the first transistor is connected to a ground through an inductor. A capacitor varying unit(500) is formed between the gate terminal and the source terminal of the first transistor and includes two variable capacitance diodes and a variable voltage supply unit(502) supplying the variable voltage between the first and second variable capacitance diodes. Each variable capacitance diode is an accumulation mode type varactor diode.