Reference : UMR6164-DAVGON-008
Workplace : RENNES
Date of publication : Thursday, November 10, 2022
Scientific Responsible name : David GONZALEZ
Type of Contract : PhD Student contract / Thesis offer
Contract Period : 36 months
Start date of the thesis : 2 January 2023
Proportion of work : Full time
Remuneration : 2 135,00 € gross monthly
Description of the thesis topic
A more efficient use of the available spectrum will not suffice to provide real-time data rates of around 100 Gbps foreseen for the future wireless networks beyond 5G, often referred to as 6G. Carrier frequencies beyond 100 GH, are therefore under study. More precisely, the 275-350 GHz band (already standardized) by IEEE exploits an atmospheric transmission window with attenuation <10 dB/km  and covers a total bandwidth that allows one to reach huge capacities with simple modulation schemes. Despite the existence of transmission windows, high-gain antennas must be used to compensate sub-THz path loss. Current solutions rely on conservative quasi-optical systems (mostly reflectors or lenses) and, generally, do not offer reconfiguration. Moreover, the bulkiness of such systems precludes their efficient integration on mobile platforms or urban furniture. To overcome these issues, a change of paradigm must be adopted: RF front-ends must not only satisfy the link budget over broad BWs, but be also amenable for integration on the chassis of vehicles or smart urban furniture.
The ambition of this project is to leverage metasurface (MTS) antennas to develop ultra-thin smart skins that meet these needs. MTS antennas consist of modulated impedance surfaces that gradually radiate the power carried by a surface wave launched by one port. Unfortunately, high-gain MTS antennas exhibit relatively narrow gain BWs. To overcome the physical bounds in the gain-BW product of single-port MTS antennas, we will explore MTS apertures with a limited number of input ports, through which we can sense the electromagnetic environment.
The PhD student will carry out a thorough literature review and the analysis and design of the modulat-ed MTS. Last but not least, special attention will be paid to finding the most appropriate materials and fabrication techniques. By the end of the project, at least one prototype will be fabricated and measured at IETR´s World-class testing facilities.
Required education level: Master or equivalent degree in electrical engineering, photonics or physics.
Required background: antenna theory, microwave engineering, antenna arrays, periodic structures, Terahertz radiation. Knowledge of French is not required.
 “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).
 T. Nagatsuma, G. Ducournau, and C. Renaud, “Advances in terahertz communications accelerated by photonics” Nature Photon., 10, 371–379 (2016).
 D. González-Ovejero et al., “Additive manufactured metal-only modulated metasurface antennas,” IEEE Trans. Antennas Propag., 66(11), 6106-6114 (2018).
 M. Faenzi, D. González-Ovejero, and S. Maci, “Wideband active region metasurface antennas,” IEEE Trans. Antennas Propag., 68(3), 1261-1272 (2020).
 M. Faenzi, D. González-Ovejero, and S. Maci, “Overlapped and sequential metasurface modula-tions for bi-chromatic beams generation”, Appl. Phys. Lett., 118, 181902, (2021).
This thesis is part of the French national project AROMA funded by the Agence Nationale de la Recher-che (ANR) under the JCJC programme. This interdisciplinary project will be carried out at IETR – UMR CNRS 6164 (www.ietr.fr) and it will strongly involve two of IETR's technological platforms:
- nR (NanoRennes) platform, https://www.ietr.fr/en/nr-nanorennes-platform with experience in microfabrication.
- M²ARS (Manufacturing Measurement Analysis of Radiating Systems) platform https://www.ietr.fr/en/m2ars-manufacturing-measurement-analysis-radiating-systems-platform, with experience in advanced antenna metrology and prototyping.
Constraints and risks
Nothing to report.
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