ELECTRIC FIELD COMMUNICATION SYSTEM AND PORTABLE TERMINAL

PROBLEM TO BE SOLVED: To provide an electric field communication system of high SNR by improving the utilization efficiency of transmission output, while suppressing radiation of unnecessary electromagnetic waves.SOLUTION: Since a portable terminal 4 is footwear type, the counter electrode P2 of the portable terminal 4 on the environment side can be brought close to the floor electrode P4 of an installation terminal 9 on the environment side, and thereby the stray capacitance C5 can be increased sufficiently when compared with a stray capacitance C8 (C5>>C8). As a result, almost all return path current I2 passes through a capacitor C1 at the input of a transceiver TRX1. Consequently, utilization efficiency of transmission output of a transceiver TRX2 is enhanced, and the SNR of input signal of the portable terminal 4 can be improved. Furthermore, since currents I1 and I2 of the same magnitude and reverse orientation are made to flow through the right and left legs of a human body 3, radiation of electromagnetic field from wave sources of currents I1, I2 are cancelled thus suppressing radiation of unnecessary electromagnetic waves from the legs of the human body 3.