| 摘要 |
PROBLEM TO BE SOLVED: To provide a small-sized receiver at a low cost. SOLUTION: The receiver is provided with a 1st disturbing wave attenuation circuit 24 that attenuates a disturbance wave in an intermediate frequency signal, an AGC amplifier 25 that amplifies an output signal from the 1st disturbance wave attenuating circuit 24, an AGC detector 26 that control the amplified level of the AGC amplifier 25, in response to a detection level; a demodulator 27 that demodulates the output signal from the AGC amplifier 25; and a 2nd disturbance wave attenuating circuit 28 that attenuates the disturbing wave included in an output signal from the demodulator 27, so that an output level of the signal with the reception frequency is greater than that of the disturbing wave signal. The demodulator 27 has a 90-degree phase shifter 27a, that attenuates a disturbance wave included in the output signal from the AGC amplifier 25 so as to increase an output level of the signal with the reception frequency more than a level of the disturbing wave signal. The AGC detector 26 controls the amplified level of the AGC amplifier 25, in response to an output signal from the 90-degree phase shifter 27a.
|
