We introduce a novel RF to DC wireless power transmission implantable rectenna system at Industrial, Scientific and Medical bands (ISM 902.8-928 MHz). An embedded circular antenna receives the externally emitted energy from a patch antenna and converts it to DC power by a rectifying circuit. The system is associated with a metallic reflector which is placed behind the human body enhancing the reception. The rectifying circuit efficiency and the total system’s efficiency are determined for different external antenna to human body distances and various embedded depths with or without the reflector. Experimental results, obtained in a realistic environment, validate the predicted performance and provide an initial evaluation of the transmission link. Porcine tissue and bovine tissue are both used during the measurements and results are compared against simulations.

In this paper, a complete wireless power transmission scenario is presented, including an external transmission antenna, an in-body embedded antenna, a rectifying circuit, and a powered sensor. This system operates at the Industrial, Scientific, and Medical bands (902.8–928 MHz). For the antenna design, important parameters including reflection coefficient, radiation pattern, and specific absorption rate are presented. As for the rectifying circuit, a precise model is created utilizing off-the-shelf components. Several circuit models and components are examined in order to obtain optimum results. Finally, this work is evaluated against various sensors' power needs found in literature.

In this paper, a novel miniaturized implantable circular antenna is presented. It supports both wireless information communication and wireless energy transmission at the Medical Device Radiocommunication band (MedRadio 402–405 MHz) and the industrial, scientific, and medical bands (ISM 902.8–928 MHz). The antenna is circular to avoid sharp edges while miniaturization is achieved by adding two circular slots to the patch. The main scenario includes embedding into the muscle layer of a cylindrical three-layer model of a human arm for which several parameters are analyzed (resonance, radiation pattern, and specific absorption rate). Power transmission efficiency and interaction distance limits to ensure connections are also evaluated. Finally, the design is validated by an experimental measurement in an anechoic chamber, and some new improvements are proposed.

The paper describes the sensitivity analysis of a wireless power transfer link involving an implanted antenna within the surrounding biological environment. The approach combines a 3D electromagnetic modeling and a surrogate model (based polynomial chaos expansion). The analysis takes into account geometrical parameters of the implanted antenna and physical properties of the biological tissue. It allows researchers to identify at low cost the main parameters affecting the efficiency of the transmission link.

Wireless power transfer systems, particularly those based on inductive coupling, provide an increasingly attractive way to deliver power without any physical connection or cables. There exists now a large literature about the topic, but generally each paper focuses on a single application and/or a typical design procedure or modeling technique. Since the covered published works belong to a variety of approaches, it can be a difficult task to understand the underlying physical aspects and modeling approaches, particularly for a newcomer to the field. This tutorial paper reviews and describes basic aspects required to model an inductive power transfer system, with a focus on practicality. The article is based on the author's work over a period of 10 yr. It introduces and explains the published methods and principles relevant to all aspects of an inductive link, such that no specific prior knowledge about wireless power transfer is required. The objectives can be divided into three main contributions: 1) To provide fundamental equations and basic principles of inductive power transfer, which are required to begin a design process; 2) To present these typical applications related to three levels of transferred power: electric vehicle (high power); drone (mid power) and biomedical implant (low power) to describe a large overview of practical systems; 3) To give newcomers to the topic an introduction to the modeling process and key aspects to facilitate any design process.