Marco Donald Migliore’s research while affiliated with University of Cassino and Southern Lazio and other places

For this article, we approximated the field of a leaky-wave antenna (LWA) with the field produced by a uniform linear array (ULA). This article aims to provide an initial framework for applications where the generation of an inhomogeneous wave is wished, but, at the same time, a flexibility is required that is difficult to meet with the conventional LWA design. In particular, two different configurations were considered, one with a simple Menzel antenna operating at 12 GHz, and one, relevant for practical applications, with an antenna operating at 2.4 GHz. This study aimed, in both cases, to highlight the distance at which the field produced by the phased array with the chosen sampling method can approximate effectively the one produced by a leaky-wave antenna and to verify whether this could cause issues for the targeted application.

Quantum computing is a cutting-edge paradigm in data processing that uses the principles of quantum mechanics to perform calculations. It has promising applications in various fields of engineering, including applied electromagnetism. Like any emerging technology, quantum computing has advantages and limitations that require in-depth understanding to make effective use in realworld engineering applications. This article aims to provide a simple and intuitive introduction to the fundamental principles of quantum computing, delving into the strengths and limitations inherent to this innovative technology and suggesting some applications of interest in the antennas and propagation community.

In this paper, we present electromagnetic signal and information theory (ESIT). ESIT is an interdisciplinary scientific discipline, which amalgamates electromagnetic theory, signal processing theory, and information theory. ESIT is aimed at studying and designing physically consistent communication schemes for the transmission and processing of information in communication networks. In simple terms, ESIT can be defined as physics-aware information theory and signal processing for communications. We consider three relevant problems in contemporary communication theory, and we show how they can be tackled under the lenses of ESIT. Specifically, we focus on (i) the theoretical and practical motivations behind antenna designs based on subwavelength radiating elements and interdistances; (ii) the modeling and role played by the electromagnetic mutual coupling, and the appropriateness of multiport network theory for modeling it; and (iii) the analytical tools for unveiling the performance limits and realizing spatial multiplexing in near field, line-of-sight, channels. To exemplify the role played by ESIT and the need for electromagnetic consistency, we consider case studies related to reconfigurable intelligent surfaces and holographic surfaces, and we highlight the inconsistencies of widely utilized communication models, as opposed to communication models that originate from first electromagnetic principles.

This article reviews the development of the concept of the number of degrees of freedom (DOF), or NDF, of radiated or scattered fields and of optimized sampling expansions for their adequate representation, highlighting their impact on the amount of information that a communication system exploiting electromagnetic fields can transmit. After summarizing and discussing the concept of DOF and its relationship with the mathematical properties of the radiated fields, the concept of spatial bandwidth of the electromagnetic field is reviewed. Then, the approximation of the field using band-limited functions is discussed, clarifying the convenience of sampling representations and including a new analysis of their redundancy with respect to the NDF. Finally, we provide an updated overview of their application in many fields of practical interest, both in classical areas of applied electromagnetics and in the emerging electromagnetic information theory sector.

In this paper, we exploit the enhanced penetration reachable through inhomogeneous waves to induce hyperthermia in biological tissues. We will present a leaky-wave antenna inspired by the Menzel antenna which has been shortened through opportune design and optimizations and that has been designed to optimize the penetration at the interface with the skin, allowing penetration in the skin layer at a constant temperature, and enhanced penetration in the overall structure considered. Past papers both numerically and analytically demonstrated the possibility of reducing the attenuation that the electromagnetic waves are subject to when travelling inside a lossy medium by using inhomogeneous waves. In those papers, a structure (the leaky-wave antenna) is shown to allow the effect, but such a radiator suffers from low efficiency. Also, at the frequencies that are most used for hyperthermia application, a classical leaky-wave antenna would be too long; here is where the idea of the shortened leaky-wave arises. To numerically analyze the penetration in biological tissues, this paper considers a numerical prototype of a sample of flesh, composed of superficial skin layers, followed by fat and an undefined layer of muscles.

We consider a line-of-sight communication link between two holographic surfaces (HoloSs). We provide a closed-form expression for the number of effective degrees of freedom (eDoF), i.e., the number of orthogonal communication modes that can be established between the HoloSs. The framework can be applied to general network deployments beyond the widely studied paraxial setting. This is obtained by utilizing a quartic approximation for the wavefront of the electromagnetic waves, and by proving that the number of eDoF corresponds to an instance of Landau's eigenvalue problem applied to a bandlimited kernel determined by the quartic approximation of the wavefront. The proposed approach overcomes the limitations of the widely utilized parabolic approximation for the wavefront, which provides inaccurate estimates in non-paraxial deployments. We specialize the framework to typical network deployments, and provide analytical expressions for the optimal, according to Kolmogorov's N-width criterion, basis functions (communication waveforms) for optimal data encoding and decoding. With the aid of numerical analysis, we validate the accuracy of the closed-form expressions for the number of eDoF and waveforms.

In this paper, we present an efficient method for synthesizing sparse plane wave generators (PWGs) based concentric ring arrays. In particular, we introduce a novel circularly-polarized ring source whose field on a near-field surface can be represented using only three scalar functions. Using this representation, we can simplify the synthesis, reducing substantially its computational complexity, which can be easily handled using an ordinary office PC. After using the ring sources to identify the position and excitation of the PWG elements, we can employ discrete linearly polarized sources as feeds or use different kinds of radiators. Some numerical simulations validate the proposed approach, which can obtain planar and volumetric quiet zones with good polarization purity.