FET BIAS CIRCUIT

PROBLEM TO BE SOLVED: To provide an FET bias circuit capable of applying a bias voltage which need not be adjusted individually to an FET for amplification of an FET amplifying circuit. SOLUTION: The FET bias circuit is equipped with: a monitoring FET in which a gate is connected to the gate for an amplifying FET and a source is connected to a source for the amplifying FET, and a drain current corresponding to a bias voltage is nearly in proportion to a drain current of the amplifying FET; and a constant bias circuit which applies the bias voltage placing the FET for amplification in a specified operation class by applying the bias voltage to the monitoring FET so that a drain current flowing to the monitoring FET has the specified operation class. COPYRIGHT: (C)2007,JPO&INPIT