In a master apparatus, a reference device generates a reference signal, a power feeding signal generation portion divides or multiples a frequency of the reference signal to generate a power feeding signal, a first communication carrier generation portion divides or multiples the frequency of the reference signal to generate a first communication carrier, a communication signal generation portion generates a communication signal, and a superimposition portion superimposes the communication signal on the power feeding signal. In a slave apparatus, a separation portion separates the superimposition signal into a power feeding signal and a communication signal, a second communication carrier generation portion divides or multiples a frequency of the power feeding signal separated by the separation portion to generate a second communication carrier, and a modulation and demodulation portion modulates and demodulates a data communication signal to be communicated with the master apparatus using the second communication carrier.