Practical Implementation Of Radiative Wireless Power Transfer
WPT School – Session 3 and 4 – Instructor: Hubregt J. Visser
Abstract and Session Summary:
Since the invention of radio (Hertz, Marconi) at the end of the 19th century, far-field transfer of energy has been feasible. Although radio has been further developed for the transfer of information, the idea of long-distance Wireless Power Transfer (WPT) was picked up from the beginning by Nikola Tesla and was clearly demonstrated by Harrell Noble from Westinghouse at the Chicago World Fair in 1933-1934, after which interest decreased.
The availability of compact, high-power microwave sources regained the interest in WPT and in 1964, William Brown from Raytheon demonstrated a wirelessly powered model helicopter. Again, interest decreased, since radiative WPT cannot, in a practical way, power or charge mobile phones, tablets, or laptops over several meters distance. For contactless charging these devices, inductive (resonant) WPT over very short distances has been developed.
Accepting that ‘power through the air’ is feasible only for ultra-low power applications, we can concentrate now on IoT devices such as sensors and headphones, and remotes. Given the ultra-low power levels, the design of a long-distance WPT receiver is a non-trivial task. In this Summer School lecture and assignment, the different building blocks of such a receiver, i.e., antenna, rectifier, boost converter, and load, will be discussed and designed. We will go through the design steps of a couple of practical, remotely powered applications like an electrical clock, a temperature sensor with display, and a wireless temperature and humidity sensor.
For the design, use will be made of freeware software that can be found at the following links. After completing the theory and briefly introducing the software, the participants can continue to work on a radiative WPT project to further their understanding. During the 2nd day of the school, the speaker will be available to help with questions relating to the project.
For the (virtual) assignment, we assume that you have downloaded the required freeware programs: Octave, OpenEMS and QucsStudio and that you have set the appropriate paths, necessary for operation.
The freeware can be found at:
Please read the installation guides and tutorials. Note, that we will work with QucsStudio and not Qucs.
For details we recommend the many tutorials that come with OpenEMS and the excellent tutorials that exist for QucsStudio: