Patent ID: 8680921

Claim:
An amplifying apparatus comprising: a first amplification device; a second amplification device to monitor an input/output signal of the first amplification device; a detection circuit that detects an output signal output by the second amplification device, corresponding to an input signal, which is diverged from the input signal to be input to the first amplification device, and is input to the second amplification device; and a control circuit that controls a gate voltage to be applied to the first amplification device in accordance with the output signal detected by the detection circuit, wherein the detection circuit monitors idling current until predetermined time to detect and monitor the idling current has passed since input of a synchronization signal to output a value of the idling current to the control circuit, and the control circuit, when the synchronization signal is input, adjusts the gate voltage in accordance with the value of the idling current input from the detection circuit after the predetermined time has passed since the input.