A second transmission path coupler has such a size that a signal width of a first signal that is generated by the second transmission path coupler at timings corresponding to a rising edge and a falling edge of an input signal to be input to a first transmission path coupler in a case where the input signal is transmitted to a position at which the first transmission path coupler and the second transmission path coupler perform an electric field and/or magnetic field coupling is substantially equal to or greater than a difference in a transmission delay amount corresponding to a gap of the first transmission path coupler.