| 摘要 |
PURPOSE:To reduce the power consumption and prevent the radio interference by providing a tone signal generating means, a mixing means, and a level varying means and varying the transmission output level of a signal to be modulated, which is obtained by modulating the output communication signal of the mixing means, by the level varying means in accordance with a tone signal in the received communication signal from the other party station. CONSTITUTION:After being amplified by an RF amplifier 51, the radio wave from the other party station which is received by an antenna 49 is mixed with the local oscilla tion signal from a local oscillator 53 by a mixer 52 to become an intermediate frequency signal. The output RF signal of an RF amplifier 51 is supplied to not only the mixer 52 but also a level detector 60 in a transmitting part 40, and the reception level is detected there, and a detection signal whose level is proportional to the reception level is generated. The detection signal is supplied to a tone generator 46, and the tone generator generates a tone signal, whose crest value is proportional to the level of the detection signal, and supplies it to a mixer 45. As the result, the transmission output level transmitted from the antenna 49 is minimized within the range where the other party station can receive it. |
