Transmission device, electric field communication transceiver, and electric field communication system

An electric field communication transceiver that induces an electric field based on data to be transmitted in an electric field transmission medium to transmit the data to be transmitted via the induced electric field and receives data to be received via an electric field based on the data to be received that is induced in the electric field transmission medium, the transceiver comprising:

• a transmission means configured to transmit a modulated signal obtained by modulating the data to be transmitted with an alternating signal having a predetermined frequency,
• a transmission reception electrode configured to induce an electric field based on the modulated signal in the electric field transmission medium and receive electric field based on data to be received,
• a first reactance means provided between the output of an transmission means and the transmission reception electrode so as to cause resonance with each of parasitic capacitance produced between a ground of the transmission means and an earth ground, parasitic capacitance produced between the electric field transmission medium and the ground of the transmission means, and parasitic capacitance produced between the electric field transmission medium and the earth ground,
• a second reactance means provided between the output of the transmission means and the ground of the transmission means or between the transmission reception electrode and the ground of the transmission means so as to cause resonance with each of the parasitic capacitances,
• a reception means configured to detect an electric field based on the data to be received, to convert the electric field into an electric signal, and to demodulate the signal so as to receive the data,
• a first connection means configured to disconnect a signal path from the output of the transmission means through the transmission reception electrode so as to prevent leakage of a reception signal to the transmission means at the time of receiving and to connect the signal path from the output of the transmission means through the transmission reception electrode so as to output a transmission signal to the transmission reception electrode at the time of transmitting, and
• a second connection means configured to disconnect the second reactance means from the ground of the transmission means so as to prevent leakage of the reception signal to the ground of the transmission means at the time of receiving, and to connect the second reactance means with the ground of the transmission means so as to allow the second reactance means to cause resonance at the time of transmitting.

An electric field communication transceiver that induces an electric field based on data to be transmitted in an electric field transmission medium to carry out data communication by use of the electric field and carries out data reception via an electric field based on data to be received that is induced in the electric field transmission medium,

• an alternating signal output means configured to output an alternating signal having a first frequency,
• a transmission reception electrode configured to induce an electric field based on data to be transmitted so as to transmit the data, and to detect an electric field based on data to be received so as to receive the data,
• a first reactance means provided between an output of the alternating signal output means and the transmission reception electrode, the first reactance means causing resonance between parasitic capacitance between the transmission reception electrode and an earth ground and impedance that the electric field transmission medium close to the transmission reception electrode shares with the earth ground,
• a second reactance means provided between the output of the alternating signal output means and the earth ground or between the transmission reception electrode and the earth ground, the second reactance means causing resonance between parasitic capacitance between the transmission reception electrode and the earth ground and impedance that the electric field transmission medium close to the transmission reception electrode shares with the earth ground,
• a reception means configured to detect an electric field of an alternating signal having a second frequency different from the first frequency,
• a first filter means configured to allow passage of the alternating signal having the first frequency and to block the alternating signal having the second frequency, and
• a second filter means configured to allow passage of the alternating signal having the second frequency and to block the alternating signal having the first frequency.