PURPOSE: To realize a stable high-frequency amplifier circuit deciding the output level only by a reference voltage without depending on the characteristics of constitution parts concering the high-frequency amplifier circuit.
CONSTITUTION: In the high-frequency amplifier circuit equipped with a transistor 1 directly grounding the emitter and a bias means 3 to impress a DC voltage to the base of the transistor 1 so as to obtain output signals by impressing a high frequency to the base of the transistor 1, the circuit is provided with a level detecting means 4 between a DC power source Vcc and an inductance element L2 connected to the collector so as to generate the DC voltage corresponding to the output level by cutting off the output signal on one voltage side, a reference voltage source 5 and a comparing means 6 to impress output to the bias means 3 corresponding to difference between the DC voltage corresponding to the output level and the reference voltage.
TAKAYAMA KAZUO