Advanced numerical modeling techniques and design of metasurface-based components for 5G communications

Project Information

BEYOND META

Grant agreement ID: 101064186

DOI

10.3030/101064186

Project closed

EC signature date 6 July 2022

Start date 1 November 2022

End date 31 October 2024

Funded under

• Marie Skłodowska-Curie Actions (MSCA)

Total cost

No data

EU contribution

€ 214 934,40

Coordinated by

DANMARKS TEKNISKE UNIVERSITET
Denmark

Periodic Reporting for period 1 - BEYOND META (Advanced numerical modeling techniques and design of metasurface-based components for 5G communications)

Reporting period: 2022-11-01 to 2024-10-31

Summary of the context and overall objectives of the project

BEYOND META provides a significant contribution to the wireless and mobile telecommunications sector, focused on the field of antennas and propagation, by developing a robust and powerful computational tool for the analysis and realization of metasurfaces, as an enabling technology for the production of novel components in the mm-wave region, in order to be incorporated in 5G communications systems. Furthermore, it advances the Finite Element Method through the ability to incorporate complex electromagnetic materials in numerical simulations.
Throughout the project's duration, the following four Research Objectives (ROs) were pursued:
RO1: Develop a fully numerical metasurface characterization technique, based on eigenvalue analysis of a metasurface unit cell and averaging of the field components of its supported modes.
RO2: Design a novel resonant particle of tailored electromagnetic properties for incorporation in mm-wave/ THz components, combining simultaneous electric and magnetic response at the same direction.
RO3: Design of novel fully-planar mm-wave components (such as waveguides and antennas) for future 5G communications.
RO4: Develop the Finite Element Method to incorporate arbitrarily bianisotropic materials with possible nonreciprocal properties.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Towards the fulfillment of the Research Objectives, we performed the following activities:

Regarding RO1, we developed a novel metasurface characterization technique based on eigenvalue analysis and field averaging of the field components of its supported eigenmodes, capable of returning all electric, magnetic and magnetoelectric surface susceptibilities of a general bianisotropic metasurface. Compared with the results of other techniques in the literature, it shows very good agreement, relatively to the resonance behavior of the returned values and their position at the frequency spectrum. The advantages that distinguish the proposed technique over other related methods are its foundation on the intrinsic modal information of the eigenmodes supported by the metasurface and its independence of any wave excitation schemes or involvement of analytical polarizability calculations. The described technique was published in the article "Metasurface Characterization Based on Eigenmode Analysis and Averaging of Electromagnetic Fields", in Journal of Applied Physics, vol. 134, no. 12, 2023.

Towards the fulfillment of RO2, we initially studied the behavior of electromagnetic complementary composite periodic media via an approach based on their supported eigenmodes for in-plane wave propagation, which led to the creation of the simplified Split-Ring Resonator (SRR). As a next step, we conducted the synthesis of a new metamaterial resonant particle possessing the ability to screen the electromagnetic energy at in-plane wave incidence regardless of the wave polarization, utilizing a fully numerical approach based on the revealing of the intrinsic behavior of the utilized resonator components via the computational solution of the corresponding eigenproblems. We started with the combination of a typical EC-SRR particle with a metallic cylinder placed perpendicularly at its center, with respect to the resonator’s plane. This composite medium supports the superposition of the separate modes of its components, exhibiting simultaneous negative effective permittivity and permeability at the same axis, parallel to the cylinders. The substitution of the cylinder with the proposed simplified complementary SRR leads to the fully planar version of the polarization independent SRR (PI-SRR). Subsequently, the uniplanar version of the proposed resonator was designed, based on a combination of an ordinary one-split SRR and a complementary resonator (Fig. 1 and 2). The simulation results illustrate a very consistent behavior concerning the capability of the structures to support the electric and magnetic resonant modes almost intact, without interacting with one another, as proved by their illustrated field distributions in the proximity of the scatterers.
The synthesis of the novel Complementary SRR particle is summarized in the article "Investigation of the Electromagnetic Behavior of Complementary Split-Ring Resonators: Toward a Novel CSRR Design”, IEEE Transactions on Microwave Theory and Techniques, Early Access, (2024).

Additionally, concerning RO3, a fully numerical process for the systematic design of fully-planar antennas for 5G communications frequencies was proposed, utilizing the metamaterial-enhanced SIW as the basis platform. Two different types of fully-planar antennas were designed, for integration in 5G communications platforms, exhibiting attractive characteristics such as optimized gain and bandwidth, low cost, compactness and ease-of-fabrication: A leaky-wave fully-planar two-slot antenna and an H-plane end-fire sectoral horn antenna.
This work is summarized in the article "Systematic Synthesis of Fully-planar Antennas Based on Metamaterial-enhanced SIWs for 5G Communications”, Progress in Electromagnetic Research C, Vol. 150, pp. 105-112, 2024.

Finally, for RO4, we derived a novel field-flux Finite Element formulation for the inclusion of potentially nonreciprocal bianisotropic materials in wave propagation electromagnetic problems, introducing the required port boundary condition for the efficient excitation and absorption of the electromagnetic wave. The described work was published in "Field-Flux Finite Element Formulation for Wave Propagation in Bianisotropic Media”, 17th European Conference on Antennas and Propagation (EuCAP), Florence, Italy, 2023.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The proposed novel, fully numerical, breakthrough technique for metasurface characterization, capable of treating the most general case of an arbitrarily bianisotropic, potentially nonreciprocal metasurface constitutes a very powerful tool for the design of novel metasurfaces with tailored, engineering characteristics, due to its foundation on modal analysis: Its novel and groundbreaking character lies in the numerical modal approach to a topic largely predominated by analytical or semi-analytical treatment or -in case of its numerical treatment- almost always treated as an excitation problem (involving processing of scattering parameters of multiple incidences). Therefore, it draws its robustness and correctness from the superiority of modal versus excitation treatment. It is noted that a technique which involves the fundamental, intrinsic information of an eigenvalue analysis is proved to be definitely superior to scattering parameter techniques, which solely assume the rough approximation of plane wave excitation on a structure.

The proposal and successful design of the polarization-independent particle opens the way towards the miniaturization of the printed waveguiding and leaky-wave, fully-planar structures, due to its capability of screening the electromagnetic wave of arbitrary polarization by the utilization of a single resonator type. Future design of Substrate-Integrated waveguides and antennas based on this novel particles will result to the minimization of their leakage losses and undesired radiation, contributing to the robustness and reliability of integrated mm-wave and THz platforms. The low-cost, easy-to-fabricate designed mm-wave components possess a very good potential of integration into next generation high speed circuits for indoor communications, with much lower production costs with the possibility of application from a production line with low purchase costs, suitable for start-up companies that are likely to be active all over Europe.

The proposed process for the systematic design of fully-planar antennas for 5G communications frequencies consists of a combined modal analysis and wave propagation Finite Element modeling, which leads to the accurate design of the waveguiding structure towards its leakage loss minimization. This treatment guarantees the precise synthesis of planar waveguides and leaky-wave antennas for the frequencies dedicated to 5G communications.

Regarding the advancement of the FEM: Utilization of the novel proposed FEM formulation allows for the incorporation of arbitrary bianisotropy in computational domains, something which was not previously available neither in custom FEM codes nor in any commercially available software. The proposed boundary condition is proposed first time in the literature. The novel FEM formulation may me incorporated in a commercial FEM software, towards its further utilization of potentially interested researchers.

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