| 摘要 |
<P>PROBLEM TO BE SOLVED: To perform an appropriate gain control even when a disturbing wave is mixed. <P>SOLUTION: In a receiver 1 in which an RF signal amplified by an RF amplifier 11 is converted to an IF frequency by a frequency conversion section 12, and is then amplified by an IF amplifier 15, an output signal of the IF amplifier 15 subjected to digital conversion by an ADC 21 is inputted to a demodulation section 200. An output of the ADC 21 is also filtered to a desired wave by a digital filter 22, and is then inputted to the demodulation section 200. In the demodulation section 200, reception power is calculated, and reception quality indicating the influence of a disturbing wave is detected, and controls a gain ratio of the RF amplifier 11 and the IF amplifier 15 when there is the influence of the disturbing wave. In this case, the reception quality is detected after the gain ratio is actively changed. Additionally, the presence or absence of the disturbing wave is detected by temporarily switching the analog filter 14 to wide band property. <P>COPYRIGHT: (C)2013,JPO&INPIT |
