| 摘要 |
PURPOSE:To stabilize an SN ratio in talking and to reduce the power consumption of a device by providing a received electric field intensity detector and a transmitting output power control circuit and continuously controlling the power of the transmitting output. CONSTITUTION:A receiving input signal received by an antenna 1 is converted into an intermediate frequency signal through a transmitter/receiver 2, a receiving high frequency filter 3 and a frequency mixer 4 and the intermediate frequency signal is amplified by an intermediate frequency amplifier 5 and supplied to the received electric field intensity detector 5. The detector 6 detects the level of the intermediate frequency signal and outputs a DC voltage corresponding to the received electric field input at the rate of 1 to 1 to the transmitting output power control circuit 7. Using the DC voltage as a control signal, the circuit 7 outputs transmitting electric power corresponding to the intensity of a receiving input electric field to a power amplifier 8. When the intensity of the receiving electric field is high, the intensity of an electric field on the terminating station is also high and more than a required level, so that the transmitting output power of the self-station is suppressed. When the intensity of the receiving electric field is low on the contrary, the transmitting output of the self-station is controlled so as to be increased to secure the intensity of the electric field on the terminating station. |
