| 摘要 |
PURPOSE:To unitary supervise plural automatic gain control circuits by weighting each control signal of plural automatic gain control circuits and adding them by an adder and supervising the result. CONSTITUTION:A reception input signal at a low level range is amplified to a prescribed level by a radio frequency amplifier stage in an AGC voltage control circuit 8 and up to the range having a high level in the reception input signal is amplified to a prescribed level at an intermediate frequency amplifier stage in the next AGC voltage control circuit 7. Then required weighting is applied to an AGC control voltage in the AGC voltage control circuit 8 by means of a voltage sensitivity adjusting circuit 11, required weighting is applied to the AGC control voltage in the AGC control circuit 7 by a voltage sensitivity adjustment circuit 10, both control voltages are added by an adder 9, and outputted to a DC voltmeter 6. Thus, the AGC control circuits 7,8 are unitary supervised. |
