| 摘要 |
PURPOSE: An automatic transmit gain control apparatus for base stations is provided to maintain a desired fixed gain by automatically controlling the attenuation level of a variable attenuator according to a result after detecting and comparing a signal level inputted to a base station transmitting part and a final antenna output signal level. CONSTITUTION: An output level detector(9) detects the output level of a band pass filter(7). An input level detector(12) detects the level of an intermediate frequency signal. A level comparison part(13) compares the output signals of the output level detector(9) and the input level detector(12) and outputs a difference value. A low pass filter(14) carries out low pass filtering for the signal output from the level comparison part(13). An amplifier(15) amplifies the output signal of the low pass filter(14) to a required level and controls the attenuation level of a variable attenuator(3).
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