@article {20_IEEE ACCESS_LUCAS POLO_ARRAY DESFASADORES TORNILLOS,
	title = {Mechanically Reconfigurable Linear Phased Array Antenna Based on Single-Block Waveguide Reflective Phase Shifters With Tuning Screws},
	journal = {IEEE Access},
	volume = {8},
	year = {2020},
	pages = {113487-113497},
	abstract = {This work presents the design and prototyping of a reconfigurable phased array in Ku band (16 to 18 GHz) implemented in waveguide technology. The design is based on the use of a novel seamless waveguide module integrating four reconfigurable phase shifters to adjust the relative phase shift between the unitary elements of a linear array, which are illuminated uniformly by a corporate waveguide feeding network. The phase shifters are implemented by a 90{\textdegree} hybrid coupler in waveguide technology where two of its ports are loaded with a tunable reactive load, implemented in this proof of concept with a tuning screw. The four phase shifters have been manufactured in a single part using direct metal laser sintering, avoiding the losses related to bad electric contacts and misalignments associated to multipart devices. This also simplifies the assembly of the full phased array, leading to a modular approach with three parts whose design can be addressed separately. The experimental results for the complete array antenna show great performance and demonstrate that the main-lobe of the radiation pattern can be effectively scanned continuously between the angles -25{\textdegree} and 25{\textdegree}, with a high efficiency in the whole design band thanks to the proposed waveguide implementation.},
	keywords = {antenna radiation patterns, Beam steering, Couplers, Fasteners, linear antenna arrays, phase shifters, Phased arrays},
	issn = {2169-3536},
	doi = {10.1109/ACCESS.2020.3003193},
	author = {L Polo-Lopez and J L Masa-Campos and A T Muriel-Barrado and P Sanchez-Olivares and E Garcia-Marin and J C{\'o}rcoles and J A Ruiz-Cruz}
}
@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}
}
