Programmable electromagnetic (meta)surfaces at sub-THz frequencies

Published : 1 January 2023

Spatiotemporal manipulation of the near- and far-electromagnetic (EM)-field distribution and its interaction with matter in the THz spectrum (0.1-0.6 THz) is of prime importance in the development of future communication, spectroscopy, imaging, holography, and sensing systems. Reconfigurable Intelligent (Meta)Surface (RIS) is a cutting-edge hybrid analogue/digital architecture capable of shaping and controlling the THz waves at the subwavelength scale. To democratize the RIS technology, it will be crucial to reduce its energy consumption by two orders of magnitude. However, the state-of-the-art does not address the integration, scalability, wideband and high-efficiency requirements.

Based on our recent research results, the main objective of this PhD project will be to demonstrate novel silicon-based RIS designs at 140 GHz and 300 GHz. The enhancement of the THz RIS performance will derive from a careful choice of the silicon technology and, from novel wideband meta-atom designs (also called unit cell or element) with integrated switches or Schottky diodes. The possibility of dynamically controlling the amplitude of the transmission coefficients of the meta-atoms, besides their phase, will be also investigated. Near-field illumination will be introduced to obtain an ultra-low profile. To the best of our knowledge, this constitutes a new approach for the design of high-gain antennas in the sub-THz range.

This thesis will be carried out at CEA-Leti, Grenoble ( in collaboration with IETR UMR CNRS 6164 ( and it will strongly involve CEA and IETR’s technological platforms. The PhD student will carry out a thorough literature review and the analysis, design and characterization of the silicon-based RIS.

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