| 摘要 |
PURPOSE:To make the level of a distortion component stable by leading an output of a detection circuit to a variable attenuator via an attenuation control circuit. CONSTITUTION:The variable attenuator 1 is connected to an input of a directional coupler 2 as a power distributor, a detection circuit 6 is connected to a dummy port of a directional coupler 5 applying opposite phase synthesis as a power distributor and the detection circuit 6 and the variable attenuator 1 are connected via an attenuation control circuit 7. The automatic level control circuit consists of the variable attenuator 1, the detection circuit 6 and the attenuation control circuit 7. The detection circuit 6 outputs a voltage proportional to an output level of a distortion generating element 3. The output is led to the attenuation control circuit 7. The attenuation control circuit 7 generates a voltage increasing the attenuation of the variable attenuator 1 when the output level of the distortion generating element 3 is increased and applies the voltage to the variable attenuator 1.
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