| 摘要 |
PURPOSE:To attain excellent reception at all times by providing plural loop antennas to a vehicle and switching them in a manner of time division to attain transmission and reception. CONSTITUTION:The titled device is a device transmitting a signal using an induced electromagnetic field as a medium between a transceiver 100 located at the outside of the vehicle and a transceiver 102 mounted on the vehicle, and the transceiver 101 on the vehicle has plural loop antennas 102, 103 provided to different positions of the vehicle with different loop face location and also has an antenna switching means 104 switching the said plural loop antennas in a manner of time division for transmitting and receiving a signal. Thus, even if one of the loop antennas at the transmission side is made orthogonal to one of the loop antennas at the reception side, the signal is transmitted and received by using the other loop antenna of both the sides. |
