MILLIMETER-WAVE AMPLIFIER AND BIAS CIRCUIT FOR THE SAME

摘要

PURPOSE: A super high frequency amplifier and a bias circuit for the same are provided to optimize performance by adjusting a source voltage, regardless of a change in the properties of a depletion-type FET(Field Effect Transistor) due to the process change. CONSTITUTION: An amplifier circuit amplifies a high frequency signal through a depletion-type FET(30). An input matching circuit(20) matches the inputted high frequency signal in the depletion-type FET. An output matching circuit(40) matches the amplified signal, and thereby outputs the matched signal. A bias circuit(80) gives a negative value to a voltage between a gate and a source of the depletion-type FET by applying a positive voltage to the source of the depletion-type FET. The bias circuit tunes the voltage between the gate and the source by changing the positive voltage applied to the source.