Towards a three-phase time-multiplexed planar power transmission to distributed implants

A platform has been presented for wireless powering of receivers that are arbitrarily distributed over a large area. A potential application could be powering of small implants distributed over large areas of the brain. The transmitter (Tx) consists of three overlapping layers of hexagonal planar spiral coils (hex-PSC) that are horizontally shifted to provide the best electromagnetic flux coverage. The three-layer hex-PSC array is driven by a three-phase time-division multiplexed (TDM) power transmitter that takes advantage of the carrier phase shift, coil geometries, and Rx time constant to homogeneously power the arbitrarily distributed receivers regardless of their misalignments. The functionality of the proposed three-phase power transmission concept has been verified in a scaled up HFSS/ADS simulation and compared to a conventional transmitter. The new transmitter achieves, on average, 5.8% power transfer efficiency (PTE) to the Rx at 90° angular misalignment compared to 1.4% by the conventional method.¹