Manuel Benedetti

Memory Enhanced PSO-Based Optimization Approach for Smart Antennas Control in Complex Interference Scenarios

In the framework of control methods for adaptive phased-arrays, this paper deals with complex communication scenarios by considering a memory-enhanced cooperative algorithm. Compared to existing approaches where far-field interferences are taken into account, the proposed analysis considers a more realistic situation where the jamming sources are located either in the near-field or in the far-field of the receiving antenna. In order to carefully address the arising challenges and to effectively deal with such complex environments, an optimization approach based on an enhanced particle swarm optimizer (PSO)-based algorithm is used. The obtained results seem to confirm the effectiveness of the proposed technique in terms of both signal-to-noise ratio and computational costs and complexity.

PSO-Based Real-Time Control of Planar Uniform Circular Arrays

This letter is aimed at assessing the effectiveness of the phase-only control strategy based on a customized PSO when applied to planar uniform circular arrays (PUCA) and in the presence of interferences both in the near-field and far-field of the antenna. The employed geometry seems to be suitable for a reliable and effective implementation of adaptive arrays in mobile devices thanks to its symmetry and geometric simplicity. For validation purposes, the proposed architecture is evaluated in the presence of a complex time-varying scenario both in terms of synthesized beam patterns and signal-to-interference-plus-noise ratio

Electromagnetic passive localization and tracking of moving targets in a WSN-infrastructured environment

In this paper, an innovative strategy for the passive localization of transceiver-free objects is presented. The localization is yielded by processing the received signal strength data measured in an infrastructured environment. The problem is reformulated in terms of an inverse source one, where the probability map of the presence of an equivalent source modeling the moving target is looked for. Toward this end, a customized classification procedure based on a support vector machine is exploited. Selected, but representative, experimental results are reported to assess the feasibility of the proposed approach and to show the potentialities and applicability of this passive and unsupervised technique. “(c) Institute of Physics”

An Innovative Microwave-Imaging Technique for Nondestructive Evaluation: Applications to Civil Structures Monitoring and Biological Bodies Inspection

Industrial and biomedical applications of microwave-imaging techniques based on inverse scattering integral relations become more and more important. In order to reduce computational costs and hence allow a quasi real-time processing, an innovative inversion procedure based on the use of a genetic algorithm and on the Sherman-Morrison-Woodbury matrix inversion method is presented. Selected numerical results concerning various scenarios and scatterer dimensions are presented in order to give some indications on the effectiveness and also current limitations of the proposed approach

A Hybrid Prefractal Three-Band Antenna for Multistandard Mobile Wireless Applications

In this letter, the synthesis of a miniaturized three-band planar antenna working in GSM and WiFi frequency bands is described. The reference geometry for the synthesis of the antenna is a hybrid prefractal shape obtained by integrating a Sierpinski-like and a Meander-like structure. The synthesis of the geometrical parameters of the antenna has been performed by means of a customized particle swarm strategy to yield electrical parameters within given specifications. In order to show the effectiveness of the approach, some results from the numerical synthesis procedure are described and a comparison between simulations and experimental measurements is reported.

A Numerical Assessment of the Reconstruction Effectiveness of the Integrated GA-Based Multicrack Strategy

This letter is aimed at presenting a numerical study on the reconstruction accuracy (quantitative imaging) of the integrated genetic algorithm (GA)-based multicrack strategy, thus completing the assessment previously carried out and limited to verifying the accuracy of the qualitative imaging (i.e., crack detection, location, and size estimation). The obtained results prove an acceptable reliability and accuracy of the GA-based integrated strategy also in reconstructing multiple defective regions even though the resulting performances degrade in comparison with those achieved by the same approach when used for qualitative imaging purposes.

A Fast Graph-Searching Algorithm Enabling the Efficient Synthesis of Sub-Arrayed Planar Monopulse Antennas

An innovative approach in its different implementations for the synthesis of compromise sum and difference patterns of monopulse planar arrays is presented. The synthesis method is based on a sub-arraying technique aimed at generating the compromise patterns through an optimal excitation matching procedure. By exploiting some properties of the solution space, the synthesis problem is reformulated as a combinatorial one to allow a considerable saving of computational resources. Thanks to a graph-based representation of the solution space, the use of an efficient path-searching algorithm is enabled to speed up the convergence to the compromise solution. In the numerical validation, a set of representative examples concerned with both pattern matching problems and pattern-feature optimization are reported in order to assess the effectiveness and flexibility of the proposed approach. Comparisons with previously published results and solutions obtained by a hybrid version of the approach customized to deal with the optimization of the sidelobe level (SLL) are reported and discussed, as well.

Multiple-Shape Reconstruction by Means of Multiregion Level Sets

In the framework of inverse scattering techniques for microwave imaging, this paper proposes an approach based on the integration between a multiscaling procedure and the level-set-based optimization in order to properly deal with the shape reconstruction of multiple and disconnected homogeneous scatterers. The effectiveness and robustness of the proposed approach is assessed against both synthetic and experimental data. A selected set of results concerned with complex shapes is presented and discussed.

Effective exploitation of the a priori information through a microwave imaging procedure based on the SMW for NDE/NDT applications

This paper presents an innovative microwave technique, which is suitable for the detection of defects in nondestructive-test and nondestructive-evaluation (NDT/NDE) applications where a lot of a priori information is available. The proposed approach is based on the equations of the inverse scattering problem, which are solved by means of a minimization procedure based on a genetic algorithm. To reduce the number of problem unknowns, the available a priori information is efficiently exploited by introducing an updating procedure for the electric field computation based on the Sherman-Morrison-Woodbury formula. The results of a representative set of numerical experiments as well as comparisons with state-of-the-art methods are reported. They confirm the effectiveness, feasibility, and robustness of the proposed approach, which shows some interesting features by a computational point of view as well.

A Fully-Adaptive Smart Antenna Protype: Ideal Model and Experimental Validation in Complex Interference Scenarios

In this report, the architecture of a smart antenna prototype is described and its functionality assessed. The system prototype is composed by an 8-elements linear arrays of dipoles with a finite reflecting plane and the adaptive behavior is obtained modifying a set of array weights with electronically-driven vector modulators. In order to real-time react to complex interference scenarios, the system is controlled by a software control module based on a Particle Swarm Optimizer. To demonstrate the feasibility and the effectiveness of the proposed implementation, a set of representative results concerned with different interface scenarios is reported and discussed. The final version of this article is available at the url of the journal PIER http://www.jpier.org/PIER/