Semiconductor device and communication device including the same

A semiconductor device comprising:

• a first amplifier including a first transistor configured to turn on according to a first input signal, a second transistor configured to turn on according to a second input signal, a third transistor connected to one end of the first transistor and configured to turn on according to a feedback signal, and a fourth transistor connected to one end of the second transistor and configured to turn on according to the feedback signal;
• a feedforward circuit including a fifth transistor configured to turn on according to the first input signal, a sixth transistor configured to turn on according to the second input signal, a seventh transistor connected to one end of the fifth transistor and configured to turn on according to a bias signal, and an eighth transistor connected to the one end of the second transistor and configured to turn on according to the feedback signal;
• a second amplifier including a ninth transistor having a gate terminal connected between the first transistor and the third transistor and a drain terminal configured to receive a first output signal and a tenth transistor having a gate terminal connected between the second transistor and the fourth transistor and a drain terminal configured to receive a second output signal;
• and
• a common-mode feedback circuit configured to receive the first output signal and the second output signal and generate a feedback signal to adjust an average of the first output signal and the second output signal to correspond to a reference signal and output the feedback signal.

A communication device comprising:

• a reception mixer configured to down-convert an output of a low-noise amplifier, an output of the reception mixer including a first input signal and a second input signal;
• a reception amplifier configured to amplify the output of the reception mixer and output the amplified output, the reception amplifier including an amplifier configured to amplify the first input signal and the second input signal and output a first output signal and a second output signal, a common-mode feedback circuit configured to receive the first output signal and the second output signal and generate a feedback signal to adjust an average of the first output signal and the second output signal to correspond to a reference signal and output the feedback signal, and a feedforward circuit configured to receive the first input signal and the second input signal and the feedback signal and perform feedforward control on the first output signal and the second output signal on a basis of the first input signal and the second input signal and the feedback signal;
• and
• a reception filter configured to filter the output of the reception amplifier,
• wherein feedforward circuit includes a first transistor configured to receive a bias voltage to control a fixed current to flow into the feedforward circuit while the feedforward circuit is enabled, and a second transistor configured to receive the feedback signal from the common-mode feedback circuit to control a bias current having a variable level to flow into the feedforward circuit while the feedforward circuit is enabled.