BUSCADOR RECOLECTA

A multipolar formulation is adopted to investigate
the absorption and scattering processes involved in near-field
interactions. This approach allows one to determine the upper
bounds for the absorbed and radiated powers that would be
achieved by an ideal lossless sensor, which are of particular
interest, for example, to wireless power transfer (WPT), wireless
sensors and near-field coupled radiators. The multipolar formulation
also helps to extricate the fundamental compromises
that must be addressed in the design of such systems, as
well as to identify strategies that could approach their best
possible performances. The general theory is illustrated with an
example consisting of a coated sensor illuminated by a Hertzian
dipole, which is a representative example of any scattering
or radiating system based on small resonators. The example
also serves to compare the performance characteristics obtained
with different phenomena such as multipolar resonances, phaseinduced
interference effects and cloaking., This work was supported in part by the Spanish Ministry of Science and
Innovation, Direcci´on General de Investigaci´on y Gesti´on del Plan Nacional
de I+D+I, Subdirecci´on General de Proyectos de Investigaci´on, Project Nos.
TEC2009-11995 and CSD2008-00066 and by NSF contract number ECCS-
1126572.

Trabajo presentado al 7th European Conference on Antennas and Propagation (EuCAP). Suecia, 2013., A pin surface structure has been used in order to
suppress undesired modes in a packaged W-band RF front-end
receiver. A parametric analysis has been carried out in order to
determine the optimum dimensions. Resonances suppression has
been demonstrated., This work was supported by the Spanish Ministry of Science
and Innovation Project Nos. TEC2009-11995 and IPT-2011-
0960-390000.

Near-field electromagnetic trapping of particles is generally obtained bymeans of gradient forces. In this paper,
we discuss the attractive behavior of curl-spin forces, as well as their potential for near-field electromagnetic
trapping and manipulation. It is demonstrated that curl-spin forces enable the trapping of particles operating at
their resonant frequency. Such phenomena can be exploited to design more efficient and selective electromagnetic
traps, to boost near-field energy exchange systems, and to bring stability to coupled resonant radiators. It also is
illustrated how the balance between the gradient, radiation pressure, and curl-spin force components leads to the
formation of zero-force rings around their sources, which explicitly demarcate the trapping regions. Analytical
and numerical analyses are presented to assess the stability of the trapping mechanism., This work was supported by the Spanish Ministry of
Science and Innovation, ProjectsNo. TEC2009-11995 and No.
CSD2008-00066 and by NSF Contract No. ECCS-1126572.

This paper presents the design, fabrication and characterization of a planar broadband chessboard structure to reduce the radar cross-section (RCS) of an object. The chessboard like configuration is formed by combining two artificial magnetic conductor (AMC) cells. The bandwidth limitations intrinsic to AMC structures are overcome in this work by properly selecting the phase slope versus frequency of both AMC structures. 180 degrees phase difference has been obtained over more than 40% frequency bandwidth with a RCS reduction larger than 10dB. The influence of the incidence angle in the working bandwidth has been performed. A good agreement between simulations and measurements is achieved., This work was supported by the
Spanish Ministry of Economy and Competitiveness Project Nos.TEC-2009-
11995, CSD 2008-00066 and INNPACTO IPT-2011-0960-390000

Circuit and multipolar approaches are presented to investigate the correlation between absorption and scattering processes in 2D problems. This investigation was inspired by earlier works of Prof.R.E. Collin, which pointed out deficiencies of the Th'evenin/Norton circuit models to evaluate the scattered and absorbed powers associated with receiving antennas and, thus, encouraged research on new analytical tools to address these problems. Power balance results are obtained with both circuit and multipolar approaches that are fully consistent. This analysis serves to illustrate how the correlation between absorption and scattering processes results in upper bounds for their power magnitudes, as well as stringent design trade-offs in both far-field and near-field source and scattering technologies., This work was supported in part by the Spanish Ministry of Science
and Innovation, Projects No. TEC2009-11995 and No. CSD2008-00066
and by the NSF Contract No. ECCS-1126572.

This contribution presents a theoretical modelling
of the scattering of ferromagnetic microwires in free-space and
inside a rectangular waveguide, providing both an analytical
solution and a physical interpretation of the problem. Special
attention is devoted to the impact of the microwire radius and its
magnetic properties. Theoretical results have been experimentally
verified measuring the reflection, absorption and transmission
coefficients of a ferromagnetic microwire inside a rectangular
waveguide., This work was supported by the Spanish Ministry of
Science and Innovation under Project TEC2009-11995 and Project CSD2008-
00066.

A pin surface structure has been used in the upper
metal plate of a packaged W-band RF front-end receiver in order
to suppress the propagation of unwanted modes. A full parametric
analysis of the periodic structure within the irreducible
Brillouin zone has been carried out in order to understand
the behavior of the pin surface and determine the optimum
dimensions for its operation in the full W-band. Resonances
suppression has been demonstrated in the W-band both in
simulation and experimentally., This work was supported by the Spanish Ministry
of Science and Innovation under Project TEC2009-11995, Project IPT-2011-
0960-390000, and Project CONSOLIDER CSD2008-00066.

The design of a horn antenna based on electromagnetic band-gap structures (EBGs) and fed by evanescent fields in the containing periodic structure is presented. Such all-dielectric antennas can form compact arrays and provide a promising solution for millimeter, submillimeter, and terahertz (THz) devices. An evanescently fed EBG horn antenna design based on a woodpile structure and operating at frequencies around 110 GHz is presented, together with experimental and simulation results for an analogous scaled-up prototype antenna operating in the Ku-band. It exhibits a 9%bandwidth and an average level of maximum gain approximately equal to 14.6 dBi., This work was supported by the
Spanish Ministry of Science and Innovation Project Nos. TEC2009-11995 and
CSD2008-00066.