| 摘要 |
PURPOSE:To reduce the spread of a transmission spectrum and the effect on the communication of other adjacent equipment by applying band limit to a signal extracted by a coupler, detecting the result to control the attenuation of a variable attenuator, and reducing the output at the time of producing distortion of the amplifier. CONSTITUTION:A 1st detector 6A and a 1st controller 7A are connected to a coupler 5A, the attenuation of a variable attenuator 2 is controlled in response to the level of an output signal to make the output level constant. On the other hand, a band stop filter(BEF) 8 is connected to other coupler 5B and a 2nd detector 6B and a end controller 7B are connected to control the variable attenuator 2. When a signal is outputted as a wide spectrum at the time of producing distortion at signal input or the like, the signal is extracted by the coupler 5B, the band is limited through the BEF 8, detected by the 2nd detector 6B and the attenuation of the variable attenuator 2 is controlled by the 2nd controller 7B. Thus, the output is decreased quickly and the interference on an adjacent signal is suppressed and the disturbance of the communication is evaded. |
