arXiv subjects

Marco Salucci

Publications and source records attributed to Marco Salucci.

At least 19 recordsLinked to original sources

arXiv2025

A Planning Strategy for Building a Heterogeneous Smart EM Environment

This paper presents a planning strategy for the deployment of smart electromagnetic entities (SEEs) to enhance the wireless coverage and the Quality-of-Service (QoS) in large urban areas. The integration of different technological solutions such as integrated access-and-backhaul nodes (IABs), smart repeaters (SRs), and electromagnetic skins (EMSs) is here addressed to enable an effective and efficient implementation of the concept of Smart Electromagnetic Environment (SEME). By combining the features of such heterogeneous SEEs and optimizing their number, positions, orientations, and configuration, the electromagnetic (EM) coverage in a set of Regions-of-Interest (RoIs) of outdoor scenarios is recovered and/or enhanced subject to installation costs and energy consumption requirements. Numerical validations from real-world scenarios are reported to assess the effectiveness of the proposed planning scheme as well as to show the potentialities of an heterogeneous deployment of SEMEs.

eess.SY↗

arXiv2024

Co-Design of Low-Profile Linear Microstrip Arrays with Wide-Band Spatial Filtering Capabilities

The design of low-profile linear microstrip arrays with wide-band spatial filtering capabilities is dealt with. An innovative architecture, leveraging the angular selectivity of offset stacked patch (OSP) radiators, is proposed to implement phased arrays (PAs) with inter-element spacing larger than half-wavelength that feature remarkable grating lobes (GLs) suppression properties and an enhanced gain within a non-negligible down-looking scanning angular range. The PA layout is then obtained by optimizing the optimal micro-scale geometrical descriptors of the radiating elements so that the macro-scale electromagnetic (EM) features of the arising finite-size PA fulfill the user-defined requirements. A set of numerical test cases, concerned with a variation of the array size and its polarization, is presented to assess the capabilities, the flexibility, and the potentialities of the proposed spatial filtering technique (SFT) also in comparison with competitive state-of-the-art alternatives. The performance of a printed circuit board (PCB)-manufactured prototype are experimentally assessed, as well.

eess.SP↗

arXiv2024

Spline-Shaped Microstrip Edge-Fed Antenna for 77 GHz Automotive Radar Systems

An innovative millimeter-wave (mm-wave) microstrip edge-fed antenna (EFA) for 77 GHz automotive radars is proposed. The radiator contour is modeled with a sinusoidal spline-shaped (SS) profile characterized by a reduced number of geometrical descriptors, but still able to guarantee a high flexibility in the modeling for fulfilling challenging user-defined requirements. The SS-EFA descriptors are effectively and efficiently optimized with a customized implementation of the System-by-Design (SbD) paradigm. The synthesized EFA layout, integrated within a linear arrangement of identical replicas to account for the integration into the real radar system, exhibits suitable impedance matching, isolation, polarization purity, and stability of the beam shaping/pointing within the target band [76:78][GHz]. The experimental assessment, carried out with a Compact Antenna Test Range (CATR) system on a printed circuit board (PCB)-manufactured prototype, assess the reliability of the outcomes from the full-wave (FW) simulations as well as the suitability of the synthesized SS-EFA for automotive radars.

eess.SP↗

arXiv2024

An Opportunistic Source Synthesis Method for Smart Electromagnetic Environments

In the framework of the "Smart ElectroMagnetic Environment" (SEME), an innovative strategy leveraging Equivalence Source concepts is introduced for enhancing the performance of large-scale outdoor wireless communication systems. The proposed Opportunistic Sources Synthesis (OSS) approach is aimed at unconventionally synthesizing the primary source (i.e., the base transceiver station (BTS) antenna array), so that the complex scattering phenomena induced in the surrounding scatterers are profitably exploited to enhance the received power within user-defined regions of interest (RoIs). To yield a computationally feasible synthesis process, an innovative "Embedded-plus-Environment Patterns" (EPEPs) method is introduced. A set of representative numerical examples, concerned with realistic large-scale outdoor scenarios, is presented to assess the effectiveness and the efficiency of the proposed optimization-driven approach for a realistic SEME implementation.

eess.SY↗

arXiv2024

A Physics-Driven AI Approach for Microwave Imaging of Breast Tumors

In this paper, an innovative microwave imaging (MI) approach for breast tumor diagnosis is proposed that employs a differential formulation of the inverse scattering problem (ISP) at hand to exploit arbitrary-fidelity priors on the inhomogeneous reference/healthy tissues. The quantitative imaging of the unknown tumor is then rephrased into a global optimization problem, which is efficiently solved with an ad-hoc physics-driven artificial intelligence (AI) strategy inspired by the concepts and guidelines of the System-by-Design (SbD) paradigm. The effectiveness, the robustness, the reliability, and the efficiency of the proposed method are assessed against both synthetic and experimental data.

eess.SP↗

arXiv2023

Towards Real-World Indoor Smart Electromagnetic Environments -- A Large-Scale Experimental Demonstration

To the best of the authors' knowledge, this work presents the first large-scale indoor experimental assessment of an implementation of the emerging Smart ElectroMagnetic Environment (SEME) paradigm, which is based on the deployment of static-passive EM skins (SP-EMSs) to enhance the coverage in a 5 [GHz] Wi-Fi network. Unlike standard (laboratory-based) validations reported in the state-of-the-art (SoA) literature, the scenario at hand mimics a realistic indoor environment to replicate as close as possible the user experience when using commodity devices. Representative results from the experimental field trials are re-ported to confirm the performance predictions arising from the numerical studies and the tolerance analyses carried out with a commercial ray-tracing (RT) tool. Besides experimentally validating the SEME idea, this study is also aimed at (roughly) quantifying the economic advantage of a SEME implementation, relying on simple-manufacturing/low-cost field manipulating devices without any additional biasing circuitry, with respect to standard approaches that imply the densification of the active radiating sources.

eess.SY↗

arXiv2022

Multi-Scaling Differential Contraction Integral Method for Inverse Scattering Problems with Inhomogeneous Media

Practical applications of microwave imaging often require the solution of inverse scattering problems with inhomogeneous backgrounds. Towards this end, a novel inversion strategy, which combines the multi-scaling (MS) regularization scheme and the Difference Contraction Integral Equation (DCIE) formulation, is proposed. Such an integrated approach mitigates the non-linearity and the ill-posedness of the problem to obtain reliable high-resolution reconstructions of the unknown scattering profiles. The arising algorithmic implementation, denoted as MS-DCIE, does not require the computation of the Green's function of the inhomogeneous background, thus it provides an efficient and effective way to deal with complex scenarios. The performance of the MS-DCIE are assessed by means of numerical and experimental tests, in comparison with competitive state-of-the-art inversion strategies, as well.

eess.SP↗

arXiv2022

Features and Potentialities of Static Passive EM Skins for NLOS Specular Wireless Links

The ability of passive flat patterned electromagnetic skins (EMSs) to overcome the asymptotic limit of the total path attenuation (TPA) of flat metallic reflectors of arbitrary size in non-line-of-sight (NLOS) specular wireless links is assessed. Closed-form expressions for the achievable TPA in EMS-powered NLOS links as well as the condition on the panel size of EMS-screens to improve the performance of flat passive conductive screens (PCSs) with the same aperture are derived and numerically validated by considering different incidence angles, screen apertures, transmitter/receiver distances, antenna gains, meta-atom geometries, and carrier frequencies.

eess.SY↗

arXiv2022

Multi-Resolution Subspace-Based Optimization Method for the Retrieval of 2D Perfect Electric Conductors

Perfect Electric Conductors (PECs) are imaged integrating the subspace-based optimizationmethod (SOM) within the iterative multi-scaling scheme (IMSA). Without a-priori information on the number or/and the locations of the scatterers and modelling their EM scattering interactions with a (known) probing source in terms of surface electric field integral equations, a segment-based representation of PECs is retrieved from the scattered field samples. The proposed IMSA-SOM inversion method is validated against both synthetic and experimental data by assessing the reconstruction accuracy, the robustness to the noise, and the computational efficiency with some comparisons, as well.

eess.SP↗

arXiv2022

Generalized Analysis and Unified Design of EM Skins

A generalized formulation is derived for the analysis of the field manipulation properties of electromagnetic skins (EMSs) in the working regimes of interest for wireless communications. Based on such a theoretical framework, a unified method for the design of anomalous-reflecting and focusing EMSs is presented. Representative results, from a wide set of numerical experiments, are reported and validated with full-wave HFSS simulations to give the interested readers some insights on the accuracy, the effectiveness, and the computational efficiency of the proposed analysis/synthesis tools.

eess.SY↗

arXiv2021

Smart Radio Environments

This Roadmap takes the reader on a journey through the research in electromagnetic wave propagation control via reconfigurable intelligent surfaces. Meta-surface modelling and design methods are reviewed along with physical realisation techniques. Several wireless applications are discussed, including beam-forming, focusing, imaging, localisation, and sensing, some rooted in novel architectures for future mobile communications networks towards 6G.

physics.class-ph↗

arXiv2021

On the Design of Modular Reflecting EM Skins for Enhanced Urban Wireless Coverage

The design of modular, passive, and static artificial metasurfaces to be used as electromagnetic skins (EMSs) of buildings for improving the coverage in urban millimeter-wave communication scenarios is addressed. Towards this end, an ad-hoc design strategy is presented to determine optimal trade-off implementative solutions that assure a suitable coverage of the areas of interest, where the signal from the base station is too weak, with the minimum complexity. More specifically, the admissible surface in the building facade is first partitioned into tiles, which are the minimum-size elements of the artificial coating (i.e., the building block of an EMS). Then, the search for the optimal EMS layout (i.e., the minimum number and the positions of the tiles to be installed) is carried out with a binary multi-objective optimization method. Representative numerical results are reported and discussed to point out the features and the potentialities of the EMS solution in the smart electromagnetic environment (SEME) as well as the effectiveness of the proposed design method.

eess.SY↗

arXiv2021

Building a Smart EM Environment -- AI-Enhanced Aperiodic Micro-Scale Design of Passive EM Skins

An innovative process for the design of static passive smart skins (SPSSs) is proposed to take into account, within the synthesis, the electromagnetic (EM) interactions due to their finite (macro-level) size and aperiodic (micro-scale) layouts. Such an approach leverages on the combination of an inverse source (IS) formulation, to define the SPSS surface currents, and of an instance of the System-by-Design paradigm, to synthesize the unit cell (UC) descriptors suitable for supporting these currents. As for this latter step, an enhanced Artificial Intelligence (IA)-based digital twin (DT) is built to efficiently and reliably predict the relationships among the UCs and the non-uniform coupling effects arising when the UCs are irregularly assembled to build the corresponding SPSS. Towards this end and unlike state-of-the-art approaches, an aperiodic finite small-scale model of the SPSS is derived to generate the training database for the DT implementation. A set of representative numerical experiments, dealing with different radiation objectives and smart skin apertures, is reported to assess the reliability of the conceived design process and to illustrate the radiation features of the resulting layouts, validated with accurate full-wave simulations, as well.

eess.SY↗

arXiv2021

Planning of EM Skins for Improved Quality-of-Service in Urban Areas

The optimal planning of electromagnetic skins (EMSs) installed on the building facades to enhance the received signal strength, thus the wireless coverage and/or the quality-of-service (QoS) in large-scale urban areas, is addressed. More specifically, a novel instance of the System-by-Design (SbD) paradigm is proposed towards the implementation of a smart electromagnetic environment (SEME) where low-cost passive static reflective skins are deployed to enhance the level of the power received within selected regions-of-interest (RoIs). Thanks to the ad-hoc customization of the SbD functional blocks, which includes the exploitation of a digital twin (DT) for the accurate yet fast assessment of the wireless coverage condition, effective solutions are yielded. Numerical results, dealing with real-world test-beds, are shown to assess the capabilities, the potentialities, and the current limitations of the proposed EMSs planning strategy.

eess.SY↗

arXiv2021

On the Use of Nonlinear Metasurfaces for Circumventing Fundamental Limits of Mantle Cloaking for Antennas

The aim of this communication is to investigate and demonstrate the possibility to overcome the fundamental limitations of mantle cloaking for antennas by exploiting nonlinear metasurfaces. First, we recap and give additional physical insights about the fundamental bounds that apply to the electric properties of an antenna that is made invisible at its own resonance frequency. Then, an innovative strategy is proposed to circumvent these limits through the introduction of nonlinear elements that are able to dynamically transform the geometry of the cloaking metasurface depending on the power level of the impinging field. Different nonlinear designs are discussed, and their effectiveness is assessed through the relevant benchmark example of a half-wavelength dipole antenna able to efficiently transmit high-power signals while being invisible to low-power ones. In addition, the capability of such nonlinear mantle cloaks to enable the shaping of the radiation pattern of an antenna array depending on the power level of the received/transmitted signal is demonstrated. These innovative cloaking devices may find applications in different radiating systems enabling unprecedented functionalities.

physics.app-ph↗

arXiv2021

Multi-Frequency GPR Microwave Imaging of Sparse Targets Through a Multi-Task Bayesian Compressive Sensing Approach

An innovative inverse scattering (IS) method is proposed for the quantitative imaging of pixel-sparse scatterers buried within a lossy half-space. On the one hand, such an approach leverages on the wide-band nature of ground penetrating radar (GPR) data by jointly processing the multi-frequency (MF) spectral components of the collected radargrams. On the other hand, it enforces sparsity priors on the problem unknowns to yield regularized solutions of the fully non-linear scattering equations. Towards this end, a multi-task Bayesian Compressive Sensing (MT-BCS) methodology is adopted and suitably customized to take full advantage of the available frequency diversity and of the a-priori information on the class of imaged targets. Representative results are reported to assess the proposed MF-MT-BCS strategy also in comparison with competitive state-of-the-art alternatives.

cs.IT↗

arXiv2021

On the Design of Complex EM Devices and Systems through the System-by-Design Paradigm -- A Framework for Dealing with the Computational Complexity

The System-by-Design (SbD) is an emerging engineering framework for the optimization-driven design of complex electromagnetic (EM) devices and systems. More specifically, the computational complexity of the design problem at hand is addressed by means of a suitable selection and integration of functional blocks comprising problem-dependent and computationally-efficient modeling and analysis tools as well as reliable prediction and optimization strategies. Thanks to the suitable re-formulation of the problem at hand as an optimization one, the profitable minimum-size coding of the degrees-of-freedom (DoFs), the "smart" replacement of expensive full-wave (FW) simulators with proper surrogate models (SMs), which yield fast yet accurate predictions starting from minimum size/reduced CPU-costs training sets, a favorable "environment" for an optimal exploitation of the features of global optimization tools in sampling wide/complex/nonlinear solution spaces is built. This research summary is then aimed at (i) providing a comprehensive description of the SbD framework and of its pillar concepts and strategies, (ii) giving useful guidelines for its successful customization and application to different EM design problems characterized by different levels of computational complexity, (iii) envisaging future trends and advances in this fascinating and high-interest (because of its relevant and topical industrial and commercial implications) topic. Representative benchmarks concerned with the synthesis of complex EM systems are presented to highlight advantages and potentialities as well as current limitations of the SbD paradigm.

eess.SP↗

arXiv2021

A Bayesian Compressive Sensing Approach to Robust Near-Field Antenna Characterization

A novel probabilistic sparsity-promoting method for robust near-field (NF) antenna characterization is proposed. It leverages on the measurements-by-design (MebD) paradigm and it exploits some a-priori information on the antenna under test (AUT) to generate an over-complete representation basis. Accordingly, the problem at hand is reformulated in a compressive sensing (CS) framework as the retrieval of a maximally-sparse distribution (with respect to the overcomplete basis) from a reduced set of measured data and then it is solved by means of a Bayesian strategy. Representative numerical results are presented to, also comparatively, assess the effectiveness of the proposed approach in reducing the "burden/cost" of the acquisition process as well as to mitigate (possible) truncation errors when dealing with space-constrained probing systems.

cs.IT↗