| 摘要 |
PURPOSE:To suppress the fluctuation of a high frequency output by controlling an amplitude control circuit so as to bring a level of a rectified signal by a diode into a prescribed level based on an output control signal, comparing the rectified signal and a reference control signal by a detection circuit so as to control the sent high frequency output by means of its comparison signal. CONSTITUTION:A signal of a base station received by an antenna 7 is detected by a detection circuit 14 and an output control signal of a transmission high frequency output is detected by an output control signal detection circuit 15 and the signal is fed to an attenuator 10 and a D/A converter 13. When an output control signal is fed to the D/A converter 13, the reference signal is voltage-divided by the output control signal in a prescribed ratio such as 1/2 or 1/4 and the result is fed to a comparator 11 as a reference control signal. Thus, the output of the diode 9 and the D/A converter 13 is compared by the comparator 11, the comparison signal of the comparator 11 is amplified by a buffer amplifier 12, and fed back as the gain control signal of the driver amplifier 2, then the high frequency output corresponding to the output control signal is sent from the antenna 7 to the base station.
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