Anti-Symmetric Wing Transmitter for Angular Misalignment Insensitive Wireless Power Transfer to Biomedical Implants

Abstract

This paper presents an anti-symmetric wing transmitter (ASW-Tx) for angular misalignment insensitive WPT to biomedical implants. Symmetrical field distribution on two orthogonal planes of Oxz and Oyz are analyzed theoretically to obtain stable power transfer efficiency (PTE) by rotating Rx around the Oz axis. Moreover, toroidal magnetic fluxes are generated by ASW to adapt with different Rx's tilted angles on Ox and Oy axes. An impedance matching network (IMN) is proposed and implemented to match ASW-Tx's impedance to source impedance. An implantable Rx is employed to verify the ASW-Tx's performance. Experimental measurements are carried out with selected Rx's tilted angles (vary from 0 o to 90 o around Ox, Oy, and Oz axis) to validate the effectiveness of proposed ASW-Tx's. Verification results show that a stable efficiency variation was achieved with a maximum fluctuation of 4dB by rotating Rx tilted angles. Moreover, the ASW-Tx can supply power effectively with a transmission efficiency of up to −18.4dB to an implantation depth of 15mm. INDEX TERMS Anti-symmetric wing transmitter (ASW-Tx), biomedical implants, impedance matching network (IMN), misalignment tolerance, Wireless Power Transfer (WPT).