The Experts below are selected from a list of 37164 Experts worldwide ranked by ideXlab platform

Andrea Massa - One of the best experts on this subject based on the ideXlab platform.

  • a total variation sparseness promoting method for the synthesis of contiguously clustered Linear Arrays
    arXiv: Information Theory, 2021
    Co-Authors: Nicola Anselmi, Giacomo Oliveri, Giorgio Gottardi, Andrea Massa
    Abstract:

    By exploiting an innovative total-variation compressive sensing (TV-CS) formulation, a new method for the synthesis of physically contiguous clustered Linear Arrays is presented. The computation of the feed network excitations is recast as the maximization of the gradient sparsity of the excitation vector subject to matching a user-defined pattern. The arising TV-CS functional is then optimized by means of a deterministic alternating direction algorithm. A selected set of representative numerical results, drawn from a wide validation, is reported to illustrate the potentialities and the limitations of the proposed approach when clustering Arrays of both ideal and realistic antenna elements. Comparisons with some competitive state-of-the-art subarraying techniques are performed as well.

  • Optimal CP-based Synthesis of Real Linear Arrays
    2018 IEEE International Symposium on Antennas and Propagation & USNC URSI National Radio Science Meeting, 2018
    Co-Authors: Nicola Anselmi, Paolo Rocca, Lorenzo Poli, Andrea Massa
    Abstract:

    In this paper the synthesis of Linear Arrays of real (non-isotropic) elements is addressed. The problem is formulated without using any approximation on the embedded element pattern generated by each single radiating element and a Convex Programming (CP)-based method is used to determine the optimal array weights aimed at generating a radiation pattern subject to arbitrary upper-bound constraints while maximizing the directivity. A preliminary numerical result involving a comparison with an analytic method is presented to prove the effectiveness of the proposed methodology.

  • Synthesis of Modular Contiguously Clustered Linear Arrays Through a Sparseness-Regularized Solver
    IEEE Transactions on Antennas and Propagation, 2016
    Co-Authors: Giacomo Oliveri, Marco Salucci, Andrea Massa
    Abstract:

    An innovative methodology for the design of modular and contiguously-clustered Linear Arrays is proposed. The approach formulates the subarraying problem as a pattern matching one in which elementary modules taken from a user-defined dictionary are combined to synthesize the final antenna layout. By recasting such a synthesis problem within the compressive sensing framework, an efficient solver is used to determine the array architecture starting from the a priori specification of the features (e.g., the length) of the admissible subArrays. A set of representative numerical experiments is discussed to assess the advantages and drawbacks of the proposed algorithm also in comparison with some state-of-the-art methods.

  • an effective approach to the synthesis of phase only reconfigurable Linear Arrays
    IEEE Transactions on Antennas and Propagation, 2012
    Co-Authors: A F Morabito, Andrea Massa, Paolo Rocca, Tommaso Isernia
    Abstract:

    We present an effective approach to the optimal mask-constrained power pattern synthesis of uniformly spaced array antennas able to dynamically reconfigure their radiation pattern by modifying only the excitation phases. The proposed approach results in a design procedure having a very low computational burden and, by exploiting at best the knowledge available in the separate synthesis of each pattern, is able to solve the underlying combinatorial optimization problem and to achieve solutions close (or equivalent) to the global optimum. A set of representative examples are reported in order to validate the proposed approach. Some extensions of the developed theory to cases other than Linear Arrays are also outlined.

  • sideband radiation reduction exploiting pattern multiplication in directive time modulated Linear Arrays
    Iet Microwaves Antennas & Propagation, 2012
    Co-Authors: Lorenzo Poli, Paolo Rocca, Andrea Massa
    Abstract:

    The reduction of the power losses in the sideband radiation of directive time-modulated Linear Arrays is addressed. The approach is based on the optimisation of the pulse sequence modulating the static excitations of the array elements to exploit pattern multiplication effects such that the sideband level of the harmonic pattern term related to the array factor is balanced by the element pattern distribution. A set of representative numerical results is reported and discussed to illustrate the potentialities and the limitations of the proposed approach.

Giorgio Montisci - One of the best experts on this subject based on the ideXlab platform.

  • Shaped beam synthesis technique for Linear Arrays of waveguide longitudinal slots
    Proceedings of the 2012 IEEE International Symposium on Antennas and Propagation, 2012
    Co-Authors: Giovanni Andrea Casula, Giuseppe Mazzarella, Giorgio Montisci
    Abstract:

    A synthesis technique for Linear Arrays of waveguide shunt slots, with a shaped beam, has been developed, generalizing Elliot's procedure, which is limited to pencil beam Arrays. The results of the proposed technique have been validated through comparison with a commercial FEM software.

  • design of circularly polarized waveguide slot Linear Arrays
    IEEE Transactions on Antennas and Propagation, 2006
    Co-Authors: Giorgio Montisci
    Abstract:

    A design procedure for circularly polarized waveguide slot Linear Arrays is presented. The array element, a circularly polarized radiator, consists of two closely spaced inclined radiating slots. Both the characterization of the isolated element and the evaluation of the mutual coupling between the array elements are performed by using a method of moments procedure. A number of traveling wave Arrays with equiphase excitations are designed and then analyzed using a finite element method commercial software. A good circular polarization is achieved, the design goals on the far field pattern are fulfilled and high antenna efficiency can be obtained

Giacomo Oliveri - One of the best experts on this subject based on the ideXlab platform.

  • a total variation sparseness promoting method for the synthesis of contiguously clustered Linear Arrays
    arXiv: Information Theory, 2021
    Co-Authors: Nicola Anselmi, Giacomo Oliveri, Giorgio Gottardi, Andrea Massa
    Abstract:

    By exploiting an innovative total-variation compressive sensing (TV-CS) formulation, a new method for the synthesis of physically contiguous clustered Linear Arrays is presented. The computation of the feed network excitations is recast as the maximization of the gradient sparsity of the excitation vector subject to matching a user-defined pattern. The arising TV-CS functional is then optimized by means of a deterministic alternating direction algorithm. A selected set of representative numerical results, drawn from a wide validation, is reported to illustrate the potentialities and the limitations of the proposed approach when clustering Arrays of both ideal and realistic antenna elements. Comparisons with some competitive state-of-the-art subarraying techniques are performed as well.

  • Synthesis of Modular Contiguously Clustered Linear Arrays Through a Sparseness-Regularized Solver
    IEEE Transactions on Antennas and Propagation, 2016
    Co-Authors: Giacomo Oliveri, Marco Salucci, Andrea Massa
    Abstract:

    An innovative methodology for the design of modular and contiguously-clustered Linear Arrays is proposed. The approach formulates the subarraying problem as a pattern matching one in which elementary modules taken from a user-defined dictionary are combined to synthesize the final antenna layout. By recasting such a synthesis problem within the compressive sensing framework, an efficient solver is used to determine the array architecture starting from the a priori specification of the features (e.g., the length) of the admissible subArrays. A set of representative numerical experiments is discussed to assess the advantages and drawbacks of the proposed algorithm also in comparison with some state-of-the-art methods.

  • harmonic beamforming in time modulated Linear Arrays
    IEEE Transactions on Antennas and Propagation, 2011
    Co-Authors: Lorenzo Poli, Giacomo Oliveri, Paolo Rocca, Andrea Massa
    Abstract:

    In this paper, the synthesis of simultaneous multibeams through time-modulated Linear Arrays is studied. Unlike classical phased Arrays where the antenna aperture is usually shared to generate multiple beams, the periodic on-off sequences controlling the static excitations are properly defined by means of an optimization strategy based on the Particle Swarm algorithm to afford desired multiple patterns at harmonic frequencies to make practical application of these harmonic beams which are typically regarded as an undesirable effect in time-modulated Arrays. The synthesis of simultaneous broadside sum and difference patterns, flat-top and narrow beam patterns, and steered multibeams is enabled as assessed by a set of selected results reported and discussed to show the potentialities of the proposed method. Comparisons with previously published results are reported, as well.

  • Synthesis of large sparse Linear Arrays by Bayesian Compressive Sensing
    2011
    Co-Authors: Giacomo Oliveri, Fabrizio Robol, Matteo Carlin, Andrea Massa
    Abstract:

    An innovative methodology for the synthesis of sparse Linear Arrays with prescribed pattern features is numerically analyzed when dealing with large aperture layouts. The technique is based on a probabilistic formulation of the synthesis problem which is solved through a Bayesian Compressive Sensing (BCS) technique. A set of numerical experiments are presented to assess the features and potentialities of the BCS design approach when layouts comprising several hundred elements are at hand.

  • bayesian compressive sampling for pattern synthesis with maximally sparse non uniform Linear Arrays
    IEEE Transactions on Antennas and Propagation, 2011
    Co-Authors: Giacomo Oliveri, Andrea Massa
    Abstract:

    A numerically-efficient technique based on the Bayesian compressive sampling (BCS) for the design of maximally-sparse Linear Arrays is introduced. The method is based on a probabilistic formulation of the array synthesis and it exploits a fast relevance vector machine (RVM) for the problem solution. The proposed approach allows the design of Linear arrangements fitting desired power patterns with a reduced number of non-uniformly spaced active elements. The numerical validation assesses the effectiveness and computational efficiency of the proposed approach as a suitable complement to existing state-of-the-art techniques for the design of sparse Arrays.

Shiwen Yang - One of the best experts on this subject based on the ideXlab platform.

  • a novel application for sum difference pattern detection of signal direction using time modulated Linear Arrays
    International Symposium on Intelligent Signal Processing and Communication Systems, 2010
    Co-Authors: Xinyin Huang, Shiwen Yang, Gang Li
    Abstract:

    A novel application using the time-modulated Linear Arrays (TMLAs) in determining the direction of unknown signal with sum pattern and difference pattern for tracking radar is presented in this paper. An optimized time sequence from the differential evolution (DE) algorithm is presented to produce multiple beams simultaneously. Based on the multiple beams of the sum patterns and their corresponding difference patterns at different sidebands, the directions of incoming signals can be detect. The comparison of the performance between TMLA and conventional antenna Arrays under the same parameter demonstrate that the accuracy of the direction of target in TMLA is relatively high, and the range of angle detection is several times larger than those of the conventional antennas Arrays.

  • direction of arrival estimation in time modulated Linear Arrays with unidirectional phase center motion
    IEEE Transactions on Antennas and Propagation, 2010
    Co-Authors: Gang Li, Shiwen Yang
    Abstract:

    A novel approach for estimating the direction of arrivals (DOAs) in time modulated Linear Arrays (TMLAs) with unidirectional phase center motion (UPCM) scheme is proposed in this paper. Based on the fact that the main beams of the patterns at different sidebands can be directed at different directions, the corresponding received signals can be used to compose a received data space. Thus, the spatial locations of the far-field sources can be estimated by using multiple signal classification (MUSIC) algorithm. Simulation results of the DOA estimation in an 8-element TMLA with the UPCM scheme validate the proposed approach, where the performance such as the accuracy and resolution of the DOA estimation is obtained through Monte-Carlo simulations. As compared to the DOA estimation based on conventional uniform Linear Arrays (ULAs), a much better resolution performance is obtained.

  • a new technique for power pattern synthesis in time modulated Linear Arrays
    IEEE Antennas and Wireless Propagation Letters, 2003
    Co-Authors: Shiwen Yang, Y B Gan, Peng T Khiang
    Abstract:

    The time modulation technique is utilized for the synthesis of power patterns in Linear Arrays. The differential evolution algorithm is employed both to shape the beam requirements and to suppress the sideband patterns. Numerical results show that the time-modulated Linear array can be successfully used to synthesize power patterns and the excitation dynamic-range ratio can be reduced significantly as compared to those of conventional Arrays.

Paolo Rocca - One of the best experts on this subject based on the ideXlab platform.

  • Optimal CP-based Synthesis of Real Linear Arrays
    2018 IEEE International Symposium on Antennas and Propagation & USNC URSI National Radio Science Meeting, 2018
    Co-Authors: Nicola Anselmi, Paolo Rocca, Lorenzo Poli, Andrea Massa
    Abstract:

    In this paper the synthesis of Linear Arrays of real (non-isotropic) elements is addressed. The problem is formulated without using any approximation on the embedded element pattern generated by each single radiating element and a Convex Programming (CP)-based method is used to determine the optimal array weights aimed at generating a radiation pattern subject to arbitrary upper-bound constraints while maximizing the directivity. A preliminary numerical result involving a comparison with an analytic method is presented to prove the effectiveness of the proposed methodology.

  • an effective approach to the synthesis of phase only reconfigurable Linear Arrays
    IEEE Transactions on Antennas and Propagation, 2012
    Co-Authors: A F Morabito, Andrea Massa, Paolo Rocca, Tommaso Isernia
    Abstract:

    We present an effective approach to the optimal mask-constrained power pattern synthesis of uniformly spaced array antennas able to dynamically reconfigure their radiation pattern by modifying only the excitation phases. The proposed approach results in a design procedure having a very low computational burden and, by exploiting at best the knowledge available in the separate synthesis of each pattern, is able to solve the underlying combinatorial optimization problem and to achieve solutions close (or equivalent) to the global optimum. A set of representative examples are reported in order to validate the proposed approach. Some extensions of the developed theory to cases other than Linear Arrays are also outlined.

  • sideband radiation reduction exploiting pattern multiplication in directive time modulated Linear Arrays
    Iet Microwaves Antennas & Propagation, 2012
    Co-Authors: Lorenzo Poli, Paolo Rocca, Andrea Massa
    Abstract:

    The reduction of the power losses in the sideband radiation of directive time-modulated Linear Arrays is addressed. The approach is based on the optimisation of the pulse sequence modulating the static excitations of the array elements to exploit pattern multiplication effects such that the sideband level of the harmonic pattern term related to the array factor is balanced by the element pattern distribution. A set of representative numerical results is reported and discussed to illustrate the potentialities and the limitations of the proposed approach.

  • harmonic beamforming in time modulated Linear Arrays
    IEEE Transactions on Antennas and Propagation, 2011
    Co-Authors: Lorenzo Poli, Giacomo Oliveri, Paolo Rocca, Andrea Massa
    Abstract:

    In this paper, the synthesis of simultaneous multibeams through time-modulated Linear Arrays is studied. Unlike classical phased Arrays where the antenna aperture is usually shared to generate multiple beams, the periodic on-off sequences controlling the static excitations are properly defined by means of an optimization strategy based on the Particle Swarm algorithm to afford desired multiple patterns at harmonic frequencies to make practical application of these harmonic beams which are typically regarded as an undesirable effect in time-modulated Arrays. The synthesis of simultaneous broadside sum and difference patterns, flat-top and narrow beam patterns, and steered multibeams is enabled as assessed by a set of selected results reported and discussed to show the potentialities of the proposed method. Comparisons with previously published results are reported, as well.

  • almost time independent performance in time modulated Linear Arrays
    IEEE Antennas and Wireless Propagation Letters, 2009
    Co-Authors: Luca Manica, Paolo Rocca, Lorenzo Poli, Andrea Massa
    Abstract:

    This letter deals with the optimization of the switch-on instants of the radio-frequency (RF) switches used for the synthesis of time-modulated Linear Arrays (TMLAs). It is shown that these additional degrees of freedom allow one to increase the stability of the pattern instantaneously radiated by the antenna. Representative results, obtained by means of a particle swarm (PS) optimization, are reported and discussed.