VOLTAGE-CONTROLLED AMPLIFIER

PROBLEM TO BE SOLVED: To provide a voltage-controlled amplifier, capable of stabilizing an output bias and improving an output maximum amplitude. SOLUTION: This amplifier is provided with an amplification part provided with transistors 3c, 3d, 3e and 3f for inputting gain control signals, load resistors 5a and 5b connected to the amplification part, a gain fluctuation detection means 30 for detecting the fluctuation of the collector current of the transistors which accompany the fluctuations in the gain of the amplification part and an output stabilization means 40 connected between the transistors 3d and 3e and the load resistors 5a and 5b for correcting a current flowing to the load resistors 5a and 5b and stabilizing the output bias of the amplification part, based on the fluctuation of the collector current of the transistors detected by the gain fluctuation detection means 30.