Patent ID: 7319884

Claim:
A FM radio device comprising: a receiver that receives a radio wave signal and frequency converts and demodulates the radio wave signal; an identification signal detecting circuit that judges whether a first identification signal, that is determined in advance between a home station and a station to communicate with, is superimposed on the radio wave signal; a transmitter that outputs a transmission radio wave signal; an electric field intensity detecting circuit that detects a reception electric field intensity of the radio wave signal received by the receiver; a transmission power determining circuit that obtains a radio wave propagation state between the home station and the station to communicate with by using at least the reception electric field intensity detected by the electric field intensity detecting circuit and determines transmission power of the transmission radio wave signal output from the transmitter based upon the radio wave propagation state; a power control circuit that controls the transmission power of the transmission radio wave signal output from the transmitter so as to become the transmission power determined by the transmission power determining circuit; and an identification signal superimposing circuit that superimposes a second identification signal, that is determined in advance between the home station and the station to communicate with, on the transmission radio wave signal output from the transmitter.