| 摘要 |
PURPOSE:To set a large sum total of electric power of all transmitted signals without causing any trouble of distortion and to ensure a satisfactory carrier/ noise ratio by controlling the gain of an amplifier in accordance with the detecting level of the preceding sum total of electric power. CONSTITUTION:The sum total of electric power of all signals is detected by a total power detecting circuit 32 among some of output signals of a down variable amplifier 31, and this detecting value is sent to a comparing part 33. Thus the detecting value is compared at the part 33 with the standard value of total power set in an all-channel transmitting state. Based on the result of this comparison, a gain control part 34 outputs a gain control signal to the amplifier 31 in order to control the power at a device standard level. Receiving the gain control signal, the amplifier 31 controls its gain to ensure a satisfactory carrier/noise while keeping the distortion degree set by the total power under the standard level and then sets a high transmission level.
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