" RF energy recovery "

Title : Wireless Power Transfer for Remote Powering of Connected Sensors
In recent years, wireless power transfer and electromagnetic energy recovery have been presented as promising and viable solutions for remotely powering and/or extending the energy autonomy of small, low-power electronic devices such as sensors and actuators. These technologies are particularly relevant in the context of the Internet of Things (IoT), where the number of connected objects in various fields (home automation, industry, transport, medical, etc.) is expected to explode over the next few years. The energy autonomy of these objects is a real obstacle to complete mobility, as they are often powered by batteries. This limits their lifespan, requires regular replacement, restricts their use to easily accessible areas and raises recycling issues. Wireless power transfer involves transmitting energy by RF and microwave waves in free space, without any physical support. The receiver, often referred to as a "rectenna", consists of a receiving antenna, an RF-DC conversion circuit, an energy management circuit and a storage device. One of the main performance indicators used to evaluate these circuits is the RF-DC conversion efficiency, which depends on various parameters such as the operating frequency, the input power level and the output load. The design and optimisation of this type of circuit requires knowledge and skills in antennas, in the theory of RF and microwave circuits, particularly non-linear circuits, and in electronics.
This seminar will first look at the context, objectives, technologies and main players in wireless power transfer. It will then look at the fundamental concepts and generalities, as well as the associated components and circuit architectures. This will also be an opportunity to present some of the work carried out in the ESYCOM laboratory (CNRS UMR 9007), relating to: 1) the optimisation of energy recovery circuits at low power levels, 2) the optimisation of waveforms to increase RF-DC conversion efficiency and 3) the use of absorbing meta-surfaces in rectenna circuits. Finally, a number of prototypes and demonstrators developed within the ESYCOM laboratory as part of projects and doctoral theses will also be presented.

Title: Wireless Power Transfer for Remote Powering of Connected Sensors
In recent years, wireless power transfer (WPT) and energy harvesting have emerged as promising and sustainable solutions for remotely powering or extending the energy autonomy of small, low-power electronic devices like sensors and actuators. These technologies are especially relevant in the context of the Internet of Things (IoT), where the number of connected devices across various sectors, such as building automation, industry, transportation, and healthcare, is expected to grow rapidly in the coming years. A key challenge for these devices is energy autonomy, as many are battery-powered. This limits their lifespan, requires regular replacement, restricts their use to easily accessible areas and raises recycling issues. Wireless power transfer involves transmitting energy by RF or microwaves in free space, without requiring a material medium. The receiver, commonly known as a 'rectenna', consists of a receiving antenna, an RF-to-dc conversion circuit, an energy management circuit and a storage device. A key metric for evaluating these systems is the RF-to-dc conversion efficiency, which depends on various parameters such as operating frequency, input power level, and output load. The design and optimisation of this kind of circuit requires knowledge and skills in antennas, in the theory of RF and microwave circuits, particularly non-linear circuits, and in electronics. This workshop will first address the context, objectives, technologies and the main worldwide leaders in wireless power transfer. It will then focus on the fundamental concepts and generalities, as well as the components and architectures of the associated circuits. It will also provide a brief overview of some of the work carried out in the ESYCOM laboratory (CNRS UMR 9007) on : 1) optimization of rectenna circuits at low power levels, 2) power optimized waveforms to enhance the RF-to-dc conversion efficiency and 3) the use of absorbing metasurfaces in WPT and Energy harvesting circuits. Finally, some prototypes and demonstrators developed within the ESYCOM laboratory as part of projects and PhD thesis will also be presented.