Missions

A more efficient use of the spectrum will not be sufficient to achieve data rates on the order of 100 Gbit/s, as required by future networks beyond 5G, also known as “6G.” Very high carrier frequencies, above 100 GHz, are therefore being investigated [1], [2]. More specifically, the 275–350 GHz band (already standardized by IEEE [1]) takes advantage of an atmospheric transmission window with attenuation below 10 dB/km [2] and offers a total bandwidth (BW) that enables extremely high capacities using simple modulation schemes.

Despite the existence of this atmospheric window, compensating for free-space path loss at such frequencies requires the use of very high-gain antennas. Current solutions—primarily quasi-optical (lenses, reflectors)—often rely on conservative and almost exclusively passive, non-adaptive concepts. Furthermore, these approaches result in radio front-ends so bulky that integration into mobile platforms or urban infrastructure becomes impractical.

This project aims to provide a disruptive solution to address these two challenges. It seeks to explore the potential of metasurface antennas (MTS), excited by spatial waves [3], surface waves [4], or a combination of both, for the development of ultra-thin intelligent skins. In all three cases, the key challenge lies in determining an equivalent impedance modulation that enables the conversion of the wave — whether spatial or surface — excited by the source into a desired radiation pattern.

However, high-gain and low-profile versions suffer from a major limitation: their bandwidth (BW) is narrow. We will leverage our previous experience with wideband metasurface antennas [5] to overcome this limitation. To go beyond the physical constraints of the gain–bandwidth product in single-port MTS antennas, we will explore MTS apertures with a limited number of input ports, which can also be used to sense the surrounding electromagnetic environment.

[1] “IEEE standard for high data rate wireless multi-media networks--amendment 2: 100 Gb/s wireless switched point-to-point physical layer,” IEEE Std 802.15.3d-2017, 1-55 (2017).
[2] T. Nagatsuma, G. Ducournau, and C. Renaud, “Advances in terahertz communications accelerated by photonics” Nature Photon., 10, 371–379 (2016).
[3] T. Thuroczy, O. Koutsos, R. Sauleau and D. González-Ovejero, "Modeling and Design of a Folded Transmitarray Antenna on Quartz for Radiometric Applications," IEEE Int. Symp. Antennas Propag. USNC-URSI Radio Sci. Meeting (USNC-URSI), Portland, OR, USA, 2023, pp. 1577-1578,
[4] D. González-Ovejero et al., “Additive manufactured metal-only modulated metasurface antennas,” IEEE Trans. Antennas Propag., 66(11), 6106-6114 (2018).
[5] M. Faenzi, D. González-Ovejero, and S. Maci, “Wideband active region metasurface antennas,” IEEE Trans. Antennas Propag., 68(3), 1261-1272 (2020).

Activities

- The agent will be responsible for the analysis and design of high-gain planar antennas with self-alignment capabilities for sub-terahertz communications (main task). Special attention will be given to the search for the most suitable materials and manufacturing techniques.
- The agent will participate in the fabrication of devices in the cleanroom of the NanoRennes platform and in their electromagnetic characterization at the M²ARS platform facilities (secondary tasks).

Skills

- Hold a PhD in Electrical Engineering, Photonics, or Physics.
- Have skills in the fields of antennas, microwaves, and numerical modeling. Good knowledge of THz electronics or photonics will be appreciated.
- Skills and qualities: experience working in a multicultural team, ability to report effectively.
- Languages: English (B2 level of the Common European Framework of Reference or higher).

Work Context

This position is part of the French national project AROMA, funded by the French National Research Agency (ANR) under the JCJC (Young Researchers) program. This interdisciplinary project will be carried out at IETR – UMR CNRS 6164 (www.ietr.fr) and will involve close collaboration with two of IETR's technology platforms:
- The nR (NanoRennes) Platform (link), which specializes in microfabrication.
- The M²ARS (Manufacturing, Measurement, and Analysis of Radiating Systems) Platform (link), which has expertise in prototyping and antenna metrology.

The position is located in a sector under the protection of scientific and technical potential (PPST), and therefore requires, in accordance with the regulations, that your arrival is authorized by the competent authority of the MESR.

Constraints and risks

Nothing to report.