Patent ID: 7587188

Claim:
A radio wave reception device comprising: radio wave reception means which receives amplitude modulation signals; gain control means which outputs gain control signals; amplitude modulation signal amplification means which amplifies the amplitude modulation signal received from said radio wave reception means, according to the gain control signal output from said gain control means; frequency conversion means which mixes the signal output from said amplitude modulation signal amplification means with a predetermined oscillation signal, and outputs the signal as an intermediate frequency signal; intermediate frequency signal amplification means which amplifies the intermediate frequency signal output from said frequency conversion means, according to the gain control signal output from said gain control means; and detection means which detects the signal output from said intermediate frequency signal amplification means, and outputs a detection signal, wherein: said detection means includes; standard signal generating means which generates a standard signal that has the same frequency and same phase as said intermediate frequency signal, based on the signal output from said intermediate frequency signal amplification means, and subtraction means which subtracts said standard signal from said intermediate frequency signal, and said gain control means includes signal level comparing means which compares the signal level of the signal subtracted by said subtraction means with the signal level of said standard level, and said gain control signal is generated according to the comparison result by said signal level comparing means.