Power line communication system for vehicle

A power line communication (PLC) system for a vehicle comprising:

• a master using a twisted pair wire, in which core wires are connected at an end to form a loop shape, as a power line and a communication line and configured to output a high-frequency signal to the twisted pair wire to transmit a power signal and a data modulation signal;
• and
• a slave configured to receive the power signal and the data modulation signal transmitted from the master, the slave including a first aperture antenna, a second aperture antenna, a power monitoring portion, a determining portion, and a setting portion, the first aperture antenna having a loop shape and being configured to receive the power signal via the twisted pair wire by electromagnetic induction coupling of an electromagnetic field generated at the twisted pair wire in accordance with an applied current of the twisted pair wire, the first aperture antenna having an aperture region facing an aperture region between twists of the twisted pair wire, the second aperture antenna having a loop shape and being configured to receive the data modulation signal via the twisted pair wire by electromagnetic induction coupling of the electromagnetic field generated at the twisted pair wire in accordance with the applied current of the twisted pair wire, the slave being configured to operate by the power signal received via the first aperture antenna, the power monitoring portion being configured to monitor a power of the power signal received via the first aperture antenna, the determination portion being configured to determine whether to use an additional operation power received via the twisted pair wire on the basis of the power monitored by the power monitoring portion, and the setting portion being configured to set the slave to use the data modulation signal received from the second aperture antenna as the additional operation power when the determining portion determines to use the additional operation power,
• wherein
• the slave further includes a responding portion,
• the responding portion is configured to inform the master that the power supplied to the slave is low when the determining portion determines to use the additional operation power,
• the master further includes a matching control portion,
• the matching control portion is configured to perform a matching control with respect to the twisted pair wire when the master is informed by the responding portion that the power supplied to the slave is low.