Modeling and optimization of single-turn printed coils for powering biomedical implants

A new coil optimization procedure is proposed for inductively coupled wireless power transfer when square single-turn printed coils are used, by means of analytically modeling the self- and mutual-inductances, parasitic resistances, and parasitic capacitances of these coils. As an example, the average diameter and trace width of the transmitting coil and the trace width of the receiving coil are optimized when the average diameter of the receiving coil and the transfer distance are assumed to be fixed. The efficiency is improved by 30% (i.e., form 40% to 70%) in comparison with the existing optimization method.