3D-spatial efficiency optimisation of MR-WPT using a reconfigurable resonator-array for laptop applications

In this study, magnetic resonant wireless power transfer (MR-WPT) system with a reconfigurable resonator using RF switches (PIN diodes) was studied to improve and optimise the transfer efficiency (TE) in a limited three-dimensional (3D) zone for laptop applications. Generally, the TE of the MR-WPT system is decreased by a 3D spatial variation (distance and location) in between the transmitter (Tx) source and the receiver (Rx) load. To improve and optimise the TE for this spatial variation, the authors utilised RF switches in a planar arrayed coils in the Rx. The TE was optimised by the status of the coil resonator (modes 1-6, open, and short) in the Rx. The average TE of the optimal mode increased > 5% comparing with that of a certain mode in the whole range of the spatial variation (x, y, z directions; 80 × 80 × 40 cm³). In addition, they analytically and experimentally demonstrated the TE optimisation by the practical laptop model with the proposed MR-WPT system installed into a desk (yz-plane) and the wall (z-direction). Through this research, the proposed reconfigurable resonator with RF switches was shown to be possible for use as a reconfigurable efficiency optimiser in the MR-WPT system.