Thèse Antennes Millimétriques Modulaires et Dirigeables Utilisant des Substrats Biosourcés H/F - Doctorat.Gouv.Fr

Établissement : Université Grenoble Alpes École doctorale : EEATS - Electronique, Electrotechnique, Automatique, Traitement du Signal Laboratoire de recherche : Centre de Radiofréquences, Optique et Micro-nanoélectronique des Alpes Direction de la thèse : Tan Phu VUONG Début de la thèse : 2026-10-01 Date limite de candidature : 2026-05-31T23:59:59 Dans le contexte de développent durable, l'objectif principal de cette thèse est de développer un système antennaire millimétrique modulaire et dirigeable utilisant des substrats biosourcés avec le regard à la fois l'efficacité de système et l'impact environnemental.

Le système antennaire dans la bande millimétrique avec la formation de faisceau permet d'avoir un débit plus élevé pour la communication, surveillance, observation d'environnement,... et une taille plus compacte, ce qui permet de réduire la consommation des ressources naturelles, y compris des métaux.

À notre connaissance, à ce jour, aucun travail n'a été publié sur les antennes millimétrique à formation de faisceau utilisant des substrats biosourcés.
In the context of environmental-aware, not only the antenna performance but also its environmental impact should be considered toward a more sustainable communication. The bio-based substrates seem to be a potential solution to reduce the environmental impact [1]. However, these substrates raise concern about higher dielectric loss compared to traditional substrates, Rogers for example. Considering the whole life-cycle, the gain in material environmental impact could be deteriorated by the reduction in operation efficiency.

It can be found in the literature many works reported the use of bio-based substrates, including paper, PLA, PLA/flax, textile,... for RF applications. However, most of them target the frequency band bellow 10~GHz. Few of them focuses on the millimeter-wave (mmW) applications. The mmW, together with beam-forming, allows at the same time higher throughput for communication, surveillance, environmental observation,... and a smaller components size, which can reduce the use of natural resources, including metal.

To the our best knowledge, to date, there is no work has been reported on millimeter-wave steerable antenna using bio-based substrates.

Figure 1 and Figure 2 (see the attached PDF) summarize the dielectric properties of some common bio-based substrates and their reported application frequencies. They are characterized using different methods with different uncertainty.

Despite the fact that the loss tangent tends to reduce at higher frequency range, the development of mmW applications on bio-based substrates are still limited due to higher attenuation at this range. Therefore, there is a need to develop high efficiency, high gain antenna using bio-based substrates at mmW.

Two of our previous works [2, 3] shows the possibility of using paper substrate for the 28 GHz antennas with radiation efficiency better than 60%, which also enhance our competences in material characterization, design, fabrication, and measurement of bio-based antennas at mmW range. In [3], a simplified Figure-of-Merit (FoM) was proposed for directional antenna, to find the best trade-off between the antenna gain and its environmental impact. This FoM, however, relies on a lot of simplified hypothesis and may no longer valid in the beam-steering context.

In the literature, some solutions for gain enhancement have been reported including dielectric lens, meta-surface, reflector,... that can be designed separately or integrated with the main antenna. However, by loading with these structures, the antenna's input impedance may change, which require the optimization of the whole system, including the main antenna and the loading structure at the same time. Nevertheless, these loading structures are usually very large, which requires a lot of materials.

In the regards of eco-design context, a modular approach seems to be an interesting solution to be able to reuse a part of system functionalities. The antenna should work as a stand-alone with or without loading structures.

Master 2 ou équivalent, spécialité en RF, motivé(e) en innovation et soutenabilité.

Avoir expérience en conception d'antenne et formation de faisceau est un plus.