@article {12_TAP_Corcoles_CombinedArrayThinning,
	title = {Efficient Combined Array Thinning and Weighting for Pattern Synthesis With a Nested Optimization Scheme},
	journal = {IEEE Transactions on Antennas and Propagation},
	volume = {60},
	number = {11},
	year = {2012},
	month = {Nov},
	pages = {5107-5117},
	abstract = {A novel procedure to thin an antenna array which synthesizes a desired pattern with the minimum number of active elements is introduced. The proposed method yields both the active elements and their corresponding excitations of a thinned array having the minimum number of active elements needed to meet several prescribed design specifications of the radiated far-field pattern. Specifications such as achieving a minimum gain, obtaining a pattern with a maximum allowable sidelobe level or synthesizing a shaped beam pattern confined into a mask are considered. Null field directions can also be added. In order to carry out the thinning, a genetic algorithm is used, while computing the excitations is carried out through linear or quadratic programming. The procedure incorporates the generalized scattering matrix analysis of an array made up of elements whose radiated field can be expressed as a spherical mode expansion, thus taking all electromagnetic effects inherently into account. Therefore, since the presence of an element can substantially alter the array features because of mutual coupling, two types of thinning are considered: removing elements or turning them off. Numerical results of arrays made up of isotropic sources, dielectric resonator antennas and microstrip patch antennas are presented.},
	keywords = {Antenna arrays, Arrays, generalized scattering matrix, Genetic algorithms, genetic algorithms (GAs), GSM, linear programming, optimization, quadratic programming (QP), spherical wave expansion, thinned arrays, Transmission line matrix methods, Vectors},
	issn = {0018-926X},
	doi = {10.1109/TAP.2012.2207667},
	url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=6236035},
	author = {J C{\'o}rcoles and Gonz{\'a}lez, M A}
}
@article {11_TAP_CorcolesRubio_SphericalSynthesis,
	title = {Spherical-Wave-Based Shaped-Beam Field Synthesis for Planar Arrays Including the Mutual Coupling Effects},
	journal = {IEEE Transactions on Antennas and Propagation},
	volume = {59},
	number = {8},
	year = {2011},
	month = {Aug},
	pages = {2872-2881},
	abstract = {An analytical method to synthesize shaped-beam patterns with planar arrays, based on the handling of spherical waves, is proposed. Translational Addition Theorems will be used here for two different purposes: (1) relating the spherical modes produced by each element in the array to calculate the mutual coupling effects, and (2) expressing the field radiated by each element in terms of spherical modes corresponding to the whole array, to carry out a spherical-wave synthesis procedure based on the orthogonal properties of spherical modes. This field synthesis method is based on the fact that any antenna radiated field can be expressed as a discrete series of weighted spherical vector wave functions and it only requires the a priori knowledge of the Generalized Scattering Matrix of each array element considered as isolated from the rest of the array elements.},
	keywords = {antenna feeds, antenna radiated field, antenna radiation patterns, Arrays, electromagnetic coupling, electromagnetic wave scattering, field synthesis method, generalized scattering matrix, GSM, Mutual coupling, mutual coupling effect, pattern field synthesis, planar antenna arrays, planar array, planar array element, Planar arrays, S-matrix theory, Scattering, spherical wave expansion, spherical-wave synthesis procedure, spherical-wave-based shaped-beam field synthesis, translational addition theorem, translational addition theorems, weighted spherical vector wave function},
	issn = {0018-926X},
	doi = {10.1109/TAP.2011.2158950},
	url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=5871276},
	author = {J C{\'o}rcoles and Rubio, J and Gonz{\'a}lez, M A}
}
@conference {09_EuCAP_Corcoles,
	title = {Array design for different SLL and null directions with an interior-point optimization method from the generalized-scattering-matrix and spherical modes},
	booktitle = {Antennas and Propagation, 2009. EuCAP 2009. 3rd European Conference on},
	year = {2009},
	month = {March},
	pages = {1381-1385},
	abstract = {This paper presents a pattern synthesis technique for arbitrary planar arrays which can be characterized in terms of a generalized-scattering-matrix (GSM) and whose radiated field can be expressed as a spherical mode expansion (SME). The procedure yields the complex-valued excitations needed to achieve a pattern which fulfils the requirements of different sidelobe levels in different regions and several prescribed field nulls with a maximum directive gain. The formulation is based on matrix-valued functions which are computed from the GSM and the SME, so all interelement coupling effects coming from complex radiating structures used as array elements are inherently taken into account. To solve the resulting nonlinear optimization problem, a primal-dual interior-point filtering method specifically adapted to this formulation is developed. Numerical results are presented for arrays of microstrip patch antennas and dielectric resonator antennas.},
	keywords = {antenna pattern, antenna radiation patterns, antenna sidelobe level, dielectric resonator antenna, dielectric resonator antennas, electromagnetic coupling, Filtering, filtering theory, generalized scattering matrix, generalized-scattering-matrix, GSM, Hessian matrices, interelement coupling effect, interior-point optimization method, Jacobian matrices, microstrip antenna arrays, Microstrip antennas, microstrip patch antenna, Microstrip resonators, nonlinear optimization, optimisation, Optimization methods, pattern synthesis technique, planar antenna array, planar antenna arrays, Planar arrays, primal-dual interior-point filtering method, Resonator filters, S-matrix theory, spherical, spherical mode expansion, Transmission line matrix methods, wave expansion},
	url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=5067872},
	author = {J C{\'o}rcoles and Gonz{\'a}lez, M A and Rubio, J and Zapata, J}
}
@article {09_TAP_Corcoles_FourierSynthesis,
	title = {Fourier Synthesis of Linear Arrays Based on the Generalized Scattering Matrix and Spherical Modes},
	journal = {IEEE Transactions on Antennas and Propagation},
	volume = {57},
	number = {7},
	year = {2009},
	month = {July},
	pages = {1944-1951},
	abstract = {This paper presents a novel, simple pattern synthesis procedure for linear equispaced arrays which can be characterized by a generalized scattering matrix (GSM) and whose radiated field can be expressed as a weighted sum of shifted spherical waves. It can be viewed as an extension of the classic design techniques of the Fourier series (FS) method or the Woodward-Lawson frequency sampling method, to the case in which the individual antenna elements{\textquoteright} patterns and all interelement couplings are taken into account. The design procedure, which yields the excitations needed to achieve the desired pattern, is based on either the FS or the discrete Fourier transform (DFT) of the spherical mode expansion of the array radiated field, as well as on various properties associated to the FS or DFT coefficients. In this work, to compute the GSM of the array and the spherical mode expansion of the field, a validated hybrid full-wave methodology, based on the finite element method and rotation and translation properties of spherical waves, is used. Numerical results of different synthesized array patterns are presented for different arrays made up of dielectric resonator antennas and cavity-backed microstrip circular patches.},
	keywords = {Antenna array mutual coupling, cavity-backed microstrip circular patches, dielectric resonator antennas, discrete Fourier transform, discrete Fourier transforms, discrete Fourier transforms (DFT), finite element analysis, finite element method, finite element methods, Fourier series, Fourier synthesis, Frequency, generalized scattering matrix, GSM, interelement couplings, linear antenna arrays, linear arrays, linear equispaced arrays, microstrip antenna arrays, Microstrip antennas, pattern synthesis, S-matrix theory, Sampling methods, Scattering, scattering matrices, shifted spherical waves, signal sampling, spherical mode expansion, spherical modes, Transmission line matrix methods, Woodward-Lawson frequency sampling},
	issn = {0018-926X},
	doi = {10.1109/TAP.2009.2021929},
	url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=4907114},
	author = {J C{\'o}rcoles and Gonz{\'a}lez, M A and Rubio, J}
}
@conference {09_APS_Corcoles_MultibeamLP,
	title = {Multibeam synthesis with minimum SLL through linear programming from the GSM-analysis of an array},
	booktitle = {Antennas and Propagation Society International Symposium, 2009. APSURSI {\textquoteright}09. IEEE},
	year = {2009},
	month = {June},
	pages = {1-4},
	abstract = {The application of all sort of optimization techniques to different array pattern synthesis problems has been widely studied since the early days of antenna array design. Most of these works (generally having constraints on the array configuration) take for granted several assumptions, among which one can highlight considering isotropic sources and not taking into account coupling between array elements. Great advances have been achieved in the field of computational electromagnetics which allow complex radiating structures, including finite antenna arrays, to be analyzed from a full-wave approach inherently taking into account all electromagnetic effects. Recently, new techniques for the afore-mentioned pattern synthesis problems with the inclusion of this rigourous electromagentic (EM) analysis have been developed. In this work, the authors propose an EM-based design technique which yields the excitations of an arbitraty planar array to output a field pattern with minimum maximum sidelobe level (SLL) given the directions of various main beams with specified mainlobe widths and different relative amplitudes and phase differences. The array is characterized through a generalized scattering matrix (GSM) and its radiated field is expressed as a spherical mode expansion (SME). The accurate determination of the array GSM is needed to have it rigourously characterized, so the use of a full-wave technique is required in case complex antenna elements or arbitrary array configurations are considered. We develop the formulation to arrive at a standard linear programming (LP) problem. Numerical results of a linear array of dielectric resonator antennas (DRA{\textquoteright}s) are presented.},
	keywords = {Antenna arrays, array pattern synthesis, complex radiating structures, computational electromagnetics, Design optimization, dielectric resonator antennas, electromagentic analysis, Electromagnetic analysis, electromagnetic fields, Electromagnetic radiation, electromagnetic waves, generalized scattering matrix, GSM, linear antenna arrays, linear programming, minimum maximum sidelobe level, multibeam antennas, multibeam synthesis, optimization, S-matrix theory, SME, spherical mode expansion},
	issn = {1522-3965},
	doi = {10.1109/APS.2009.5171513},
	url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=5171513},
	author = {J C{\'o}rcoles and Gonz{\'a}lez, M A}
}
