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 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Oxz</i> and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Oyz</i> are analyzed theoretically to obtain stable power transfer efficiency (PTE) by rotating Rx around the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Oz</i> axis. Moreover, toroidal magnetic fluxes are generated by ASW to adapt with different Rx’s tilted angles on <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ox</i> and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Oy</i> 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° to 90° around <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ox</i> , <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Oy</i> , and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Oz</i> 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 4 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dB</i> by rotating Rx tilted angles. Moreover, the ASW-Tx can supply power effectively with a transmission efficiency of up to -18.4 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dB</i> to an implantation depth of 15 <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mm</i> .