Wireless powering and propagation of radio frequencies through tissue

Wireless powering has benefits in a variety of different areas but has the potential to revolutionize the field of medical devices. With the advantages of this technology come complexities which become exemplified when applied to an implantable setting in biomedical applications. This chapter provides an overview of some of the applications of wireless powering and focuses on far-field remote powering for implantable applications using radiative electromagnetic fields. Analytical and simulation models are presented to help illustrate and gain an intuitive understanding of RF propagation through tissue. Ex vivo experiments and in vivo studies are performed to assess the validity and accuracy of the models, and these empirical results are discussed. Lastly, the electrical components, circuit design, and system integration required for transcutaneous wireless power transfer are described. There are significant benefits of the radiative wireless powering technique, as compared to its inductive coupling counterpart, but with these advantages come extremely complex challenges.