it is become accumulation independently with physical layer circuit and the mac circuit , and an rf integrated circuit for development for the radio transmission and reception that the interface frequency with the physical layer circuit has width of at least around 10 mhz toward is related to . it is rf integrated circuit 1 for the development that the switching circuit which changes a demodulation circuit and a modulation circuit and an antenna to either of demodulation circuit 11 and modulation circuit 12 was built in , and rf integrated circuit 1 is made accumulation independently with physical layer circuit 21 and mac circuit 22 and demodulation circuit 11 converts a received radio frequency signal into a frequency signal of frequency 5 - 20 mhz , and modulation circuit 12 converts a frequency signal of frequency 5 - 20 mhz into a radio frequency signal .