A transmitter (1) applies current from a power supply node to a ground node in synchronization with only a rise of an input signal and transmits a transmission signal including an RF pulse signal to a receiver (2). The receiver (2) applies current from a node (231) on which precharge is performed to a ground node only at the reception of the RF pulse signal, decreases the potential of the node (231) from a precharge potential Va to 0 V, and outputs an H-level output signal by detecting the decreased potential 0 V. After receiving the RF pulse signal, the receiver (2) performs precharge to change the potential of the node (231) to the potential Va.