Multiplier

A multiplier having a simple constitution, excellent performance with respect to high-frequency characteristics and distortion characteristics, and allows low-voltage operation. Transistor Q, resistors R and R form a common-emitter circuit. One signal of differential signal v is amplified by the common-emitter circuit, and the amplified signal is input to an emitter follower composed of transistor Q. The output current of the emitter follower is input through resistor R into the current mirror circuit composed of transistors Q and Q. Output current I of said current mirror circuit is input to the transistor pair of transistor Q and npn transistor Q. By selecting an appropriate gain for the common-emitter circuit, currents I and I generated in this way become independent of the base-emitter voltage, and performance is improved with respect to distortion characteristics.