| 摘要 |
PURPOSE:To compensate sufficiently a distortion of an amplifier with a broad level range and a large nonlinearity by controlling an input side variable attenuator and an output side variable attenuator so that the ratio of an input level of a distortion generating circuit to an output level has a constant value. CONSTITUTION:After an input level detecting signal through a detection circuit 16 is amplified by an amplifier 31, the result is given to a control amplifier 33 constituted so as to control a predetermined amount in response to the input signal level thereby controlling the input side variable attenuator 18. Moreover, the input level detecting signal amplified by the amplifier 31 is compared with an output level detecting signal amplified by a detecting signal amplifier 32 connected to the output side of a level detecting circuit 17 by a comparison controller 34 so as to control the output side variable attenuator 19 by which the ratio of the input level to the output level is made to have a prescribed value. Thus, the distortion is compensated at a broad level range even to an amplifier having a less change due to the level of the distorted amount. |
