摘要
Recently,the inductive coupling link is the most robust method for powering implanted biomedical devices,such as micro-system stimulators,cochlear implants,and retinal implants.This research provides a novel theoretical and mathematical analysis to optimize the inductive coupling link efficiency driven by efficient proposed class-E power amplifiers using high and optimum input impedance.The design of the coupling link is based on two pairs of aligned,single-layer,planar spiral circular coils with a proposed geometric dimension,operating at a resonant frequency of 13.56 MHz.Both transmitter and receiver coils are small in size.Implanted device resistance varies from 200Ωto 500Ωwith 50Ωof stepes.When the conventional load resistance of power amplifiers is 50Ω,the efficiency is 45%;when the optimum resonant load is 41.89Ωwith a coupling coefficient of 0.087,the efficiency increases to 49%.The efficiency optimization is reached by calculating the matching network for the external LC tank of the transmitter coil.The proposed design may be suitable for active implantable devices.
