PURPOSE: To stabilize a loop action and to decrease a consumption current by sending a control signal to a variable attenuator and a variable voltage source from an electric control signal generator changing the attenuating quantity of the variable attenuator stepwise based on the control signal from the electric control signal attenuator and changing the voltage of a control terminal with an output electric power level by interlocking by means of the output voltage of the variable voltage source.

CONSTITUTION: In an automobile telephone, the sending output electric power of a terminal radio is controlled in 6-11 levels at a 4dB step in accordance with a distance between a base station and the terminal radio for decreasing an interference between same or adjacent channels and power consumption. There is a method to change a loop gain by inserting the variable attenuator 13, as a mean for changing an output electric power. Electric power control is executed by changing stepwise the attenuating quantity of the variable attenuator 13 by the control signal from the electric control signal generator 20 composed of CPU, etc. The voltage of the voltage Vd of the variable voltage source 19 is changed by the variable voltage source 19 by interlocking with the output electric level.