Design of a misalignment-robust, high-frequency GaN-based inductive power transmission system

The LAIC laboratory of CEA-LETI's Systems Department in Grenoble is specialized in the development of innovative electronic and mechatronic systems, taking into account challenges linked to energy recovery / management / transmission and sensor integration in a variety of environments. As part of the development of its R&D activities, the LAIC is offering a PhD thesis on wireless power transmission using GaN-based resonant inductive coupling.

Wireless power transmission technologies are booming, with applications in space, consumer electronics, medical, automotive and defense sectors. Power transmission technology using resonant inductive coupling appears to be the most promising in terms of near-field efficiency.

The proposed thesis will follow the development of a system including a fixed-coupling electromagnetic coupler and HF electronics based on a GaN transistor-based class-E topology. In this context, the aim of the thesis is to develop a system robust to coupler coil misalignment. The aim is to study, develop and test the performance of a new coupler and an adaptive drive electronics. The candidate will be required to develop analytical and numerical models to optimize the electronics, compare the performance of existing systems in the literature, and propose, develop and test the performance of innovative GaN-based topologies ensuring good robustness to electromagnetic coupling variation.

A multi-disciplinary profile with a focus on power electronics and physics is required for this thesis. In addition to a solid theoretical ground and strong simulation skills, the PhD student will need to be able to work as part of a team, with an aptitude for experimentation and an attraction for practical applications.

Bioinspired magnetic navigation

GPS is widely used today for land, sea and air navigation. However, it has several disadvantages: it requires a very heavy infrastructure (constellation of 24 satellites in orbit), it does not work in an “indoor” or underwater environment and above all it can be jammed. This is why “magnetic” navigation, i.e. exploiting the earth’s magnetic field, is interesting because it is completely passive and works in all environments, including underwater. Many quite different strategies exist for navigating using this geomagnetism; one way is to take inspiration from the way certain animals (such as robin, bar-tailed godwit, albatross, monarch, sea turtle, salmon, etc.) exploit the magnetic field to travel very large distances (several thousand of km).
The thesis will seek to answer the following research question: Is a bio-inspired approach relevant to implementing magnetic navigation ?

The PhD will be at CEA Grenoble ( within a team of multidisciplinary researchers: physics, electronics, signal processing ( whose work is recognized in instrumentation for geophysics and space.

Engineer/Master 2 profile in signal processing, electromagnetism, physics: apply to

Design of algorithms to optimize RADAR beam control

The arrival on the market of a new generation of Imaging Radars 4D brings new opportunities and challenges for the development of data processing algorithms. These new sensors, geared towards the autonomous vehicle market, offer greater resolution thanks to a larger number of antennas. However, this implies an increase in the amount of data to be processed, which requires significant computing resources.
The aim of this thesis is to develop algorithms to optimize Radar resolution while limiting computational costs, in order to embed processing as close as possible to the Radar. To achieve this, beamforming techniques will be used to control the shape and direction of the Radar beam, so as to concentrate the energy in regions deemed relevant. One of the challenges is therefore to create a high-performance feedback loop to control the Radar antennas according to the scene observed during previous measurements.
This thesis will take an experimental approach, using a radar owned by the laboratory. Simulation tools will also be used to test hypotheses and go beyond the possibilities offered by the equipment.

Ultra-compact electronic actuation of micro-UAVs

Reducing the size of electronic systems for micro-drones is crucial for decreasing their weight, extending their battery life, and enhancing their maneuverability. This doctoral project aims to explore innovative solutions for energy management in integrated circuits designed for high-voltage actuation of micro-motors for very small drones (weighing about one gram and measuring a few mm³). The project encompasses micromechanics, the use of new small batteries developed by CEA-Leti, and the application of advanced microelectronic technologies. Through a collaboration between Gaël Pillonnet (CEA) and Patrick Mercier (University of California, San Diego - UCSD), you will benefit from a research environment at the forefront of technology, focused on the design of integrated circuits, and more specifically, on power management circuits (Power Management IC, PMIC). This work offers an exciting applicative dimension, with the integration of the circuit and batteries into an ultra-compact assembly intended for the activation of micro-motors. By joining our team, you will contribute to the advancement of cutting-edge technologies that will have a significant impact on the micro-drone sector.

Power and data transmission via an acoustic link for closed metallic environments

This thesis focuses on the transmission of power and data through metal walls using acoustic waves. This technology will eventually enable the powering, reading and control of systems placed in areas enclosed in metal: pressure vessels, ship hulls and submarines, etc.
As electromagnetic waves are absorbed by metal, it is necessary to use acoustic waves to communicate data or power through metal walls. These are generated by piezoelectric transducers bonded to either side of the wall. Acoustic waves are poorly attenuated by metal, resulting in numerous reflections and multiple paths. It is therefore necessary to use multi-carrier communication techniques (e.g. OFDM), in order to achieve robustness and high throughput.
The aim of this thesis is to develop a robust technology demonstrator for remote powering and acoustic data communication through metal walls. This work will be based on advanced modeling of the acoustic channel to optimize the performance of the power and data transmission device. It will also involve developing innovative electronic building blocks to determine and maintain an optimum power transmission frequency, impacted by environmental conditions and typically by temperature.
The ultimate goal of this thesis will be the development and implementation of an OFDM communication system embedded in an FPGA and/or microcontroller to send sensor data through a metal wall of variable thickness. Limitations due to channel and electronic imperfections will lead to the invention of a large number of compensation methods and systems in the digital and/or analog domain. Work will also be carried out on the choice of piezoelectric transducers and channel characterization, in conjunction with the acoustic wave activities of the acoustic power transmission laboratory.