OLIVERI , Giacomo

In this paper, the synthesis of a triple-band planar antenna working in the GSM (900 and 1800 MHz) and UMTS frequency bands is presented. As reference geometry, a hybrid pre-fractal shape has been adopted by integrating a Sierpinski and a Meander-line structure. The synthesis of the antenna has been performed by optimizing the descriptive...

An Alphabet Compressive Sensing (CS) approach is proposed in this paper for the retrieval of arbitrarily-shaped targets when no a-priori information on the class of scatterers at hand is available. The approach is based on the combination of (i) a fast CS retrieval methodology that is employed to invert the field data assuming several different...

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In nonlinear inverse scattering problems, induced contrast sources are often used to model the response of the scatterers under test to the interrogating incident field. They then constitute, together with the contrast function (which includes the parameters of interest of the object under test) the problem unknowns. In this paper, an approach...

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Microwave imaging methods, i.e., approaches able to reconstruct the distributions of the dielectric characteristics of unknown objects starting from samples of the scattered electric field, are gaining a growing importance in the scientific scenario. Several new algorithms have been devised in the past few years. However, there are still open...

This paper presents an integrated inverse scattering approach to electromagnetic non-destructive evaluation. The method exploits the features of the multi-scaling scheme and the Inexact-Newton techniques for suitably addressing the ill-posedness and nonlinearity of the problem at hand. Preliminary numerical validations are reported to give an...

In this paper, a planar monopole antenna for Ultra-Wideband (UWB) communications with a notched behavior in the two sub-bands UNII1 and UNII2 of the Wireless Local Area Network (WLAN) band is presented. The antenna geometry is described by means of a spline curve and a rectangular slot. Numerical and experimental results are reported to assess...

Polarization-reconfigurable arrays play a fundamental role in radar systems in order to enhance their detection probability and cancel clutters, chaffs, and jammers. In order to reach polarization flexibility, the integration of actively controlled elements in standard array configurations is often employed, but the overall system complexity...

In this paper, an approach for the synthesis of Ultra-Wideband (UWB) antenna systems in the time domain is proposed. Starting from the definition of suitable time-domain performance indexes, the design process is based on a spline representation of the antenna shape and a Particle Swarm Optimization (PSO) aimed at matching optimal radiation and...

The inspection of 2-D scatterers buried in a lossy half-space from field measurements is formulated within the framework of the second-order Born approximation (SOBA) of the inverse scattering problem. An iterative multi-scaling approach (IMSA) is combined with a two-step inexact-Newton (IN) algorithm to solve the arising problem. A set of...

The imaging of three-dimensional scatterers is addressed by means of a new microwave inversion algorithm that combines an Inexact Newton (IN)-based deterministic reconstruction technique with a multi-focusing approach. This choice is motivated by the capability of multi-resolution techniques to reduce non-linearity issues arising in 3D imaging...

A microwave imaging technique based on the integration of the Inexact-Newton method within a multi-scaling strategy is proposed in the framework of the contrast field formulation of the electromagnetic inverse scattering. The inversion problem is solved by means of a nested procedure that considers three different logical levels: (a) an outer...

This paper presents a class of polarization-agile arrays with controlled sidelobes. The architecture is based on the interleaving of two independently polarized sub-arrays through a deterministic strategy derived from Almost Difference Sets (ADSs). The efficiency, flexibility and reliability of the proposed design technique is assessed by means...

This paper analyzes a method for the DOA estimation of correlated signals based on the integration of a SVM classifier and an iterative multi-scaling approach (IMSA). The aim of the SVM classifier is the definition of a probability map of the angular directions of incidence of the incoming signals starting from the knowledge of the correlation...

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In this paper, an approach for the synthesis of Ultra-Wideband (UWB) antennas with a notched frequency band is presented. It exploits the effectiveness of a representation based on spline curves to obtain the wideband behavior and the simplicity of using a rectangular slot for the stopband characteristic. A Particle Swarm Optimizer (PSO) is...

A novel approach for three-dimensional electromagnetic imaging is presented. This technique is a combination of an iterative multiscaling approach with an inexact-Newton method. The multiscaling procedure allows one to iteratively focus the region of interest on the detected target, whereas the inexact-Newton method provides an efficient...

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An iterative multiscaling approach for solving the electromagnetic inverse scattering problem related to the imaging of shallow subsurface targets with the ground-penetrating radar (GPR) is proposed. The approach combines the zooming properties of the multiscaling technique with the reconstruction capabilities of an Inexact-Newton (IN) method...

In this paper an Inexact-Newton method, based on the truncated Landweber algorithm, is used within a multi-resolution scheme, called the iterative multi-scale approach, in order to efficiently solve inverse electromagnetic scattering problems. In particular, the case of separated scatterers is addressed and the performances of the described...

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The recent development of many new ultra‐wideband (UWB) array technologies has created a demand for antenna elements that can effectively operate over similar bandwidths. For example, the polyfractal [1] and RPS [2] topologies are capable of exhibiting remarkably wide frequency bandwidths on the order of 20:1, 40:1 or even more, depending on...