Longitudinally Misalignment-Insensitive Dual-Band Wireless Power and Data Transfer Systems for a Position Detection of Fast-Moving Vehicles

For position detection of moving vehicles using a wireless passive sensor placed in the traveling direction, a wireless power and data transfer (WPDT) system for supplying power to the sensor is required. Particularly, in the case of a high-speed vehicle with a compact sensor environment that is convenient for installation on railways or roadways, it is difficult to operate the sensor properly due to charging time and range limitations caused by the compact sensor size. In this paper, to improve a working zone of the compact sensor, this work presents a longitudinally misalignment-insensitive dual-band WPDT system with an extended working zone. The proposed system utilizes dual transmitting and receiving coils operating at different frequencies for achieving high isolation between the power and data links, which consists of a distributed antenna array with a gap between antenna elements for wireless power transfer at 27.1 MHz and an extended rectangular loop for data communications at 4.23 MHz. It achieves an extended working zone of approximately 112% at 0.25 m distance in comparison with a conventional system with dual square coils and achieves uniform received signals within a misalignment (up to 0.53 m).