Open Access
Análisis de efecto de un superestrato left-handed en la apertura de una guía rectangular
(2005) Sáenz Sáinz, Elena; Gonzalo García, Ramón; Ederra Urzainqui, Íñigo; Maagt, Peter de; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, results showing the experimental verification of the gain improvement of a rectangular waveguide antenna when a left-handed material (LHM) is used as superstrate are presented. The improvement has been characterized by means of measuring the increase of transmission (S21 parameter) obtained when this LHM is placed between two open-ended rectangular waveguide antennas. An average increase of transmission of about 6.5 d.B has been obtained. Besides, improvements in the radiation patterns of a rectangular waveguide with a LH superstrate are analyzed. An enhancement of 3.5 dB in the directivity and a reduction of 15 dB in the back radiation have been obtained.
Open Access
Design of a slotted Substrate Integrated waveguide antenna using a metasurface
(IEEE, 2021) Chocarro Álvarez, Javier; Pérez Escudero, José Manuel; Ederra Urzainqui, Íñigo; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In this paper, the use of a metasurface to improve the radiation properties of a Substrate Integrated Waveguide based slotted antenna is proposed. The design process of a metasurface covered 8 element slot antenna array following a Chebyshev distribution is presented and its performance is compared with that of a conventional one. The results demonstrate the improvement in the radiation performance that can be achieved, without affecting the bandwidth.
Open Access
Research on metamaterials for antenna applications
(2005) Gonzalo García, Ramón; Ederra Urzainqui, Íñigo; Iriarte Galarregui, Juan Carlos; Martínez Pascual, Beatriz; Sáenz Sáinz, Elena; Cantora Álvarez, Pablo; Maagt, Peter de; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
During the last 20 years a lot of attention has been paid to apply Electromagnetic Band Gap (EBG) technology in different frequency ranges, from microwaves to optics. EBG technology is based on the use of periodic structures to prevent the electromagnetic propagation in certain frequency ranges, known as the bandgap [1]. In the last years the new and revolutionary field of Metamaterials is trying to be applied to similar applications. Although different, both technologies have some similitudes as it has been proven for different authors. For instance when working with EBG structures Left-Handed properties can be obtained in some frequency ranges. In this paper, research efforts focussed on applying EBG technology and the more recent Metamaterials, in particular, left-handed materials, to antenna subsystems at microwave and (sub)millimetre wave frequencies are introduced.
Open Access
Sub-millimetre wave imaging array configurations using EBG technology
(2004) Ederra Urzainqui, Íñigo; Gonzalo García, Ramón; Martínez Pascual, Beatriz; Río Bocio, Carlos del; Azcona, L.; Alderman, B.; Huggard, P.G.; Hon, B.P. de; Beurden, M.C. van; Marchand, L.; Maagt, Peter de; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Open Access
Domain integral equations for electromagnetic band-gap slab simulations
(2004) Hon, B.P. de; Beurden, M.C. van; Gonzalo García, Ramón; Martínez Pascual, Beatriz; Ederra Urzainqui, Íñigo; Río Bocio, Carlos del; Azcona, L.; Alderman, B.; Huggard, P.G.; Maagt, Peter de; Marchand, L.; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Electromagnetic band-gap substrates o er advantages regarding cross-coupling in sub-mm range imaging array applications. Electromagnetic scattering by such substrates may e ectively be formulated in terms of integro- di erential equations. The scattered elds are evaluated via the spectral domain in which the 3-D problem reduces to an in nite system of coupled 1-D integro-di erential equations. The associated matrix-vector products are dominated by FFTs. For moderate frequencies an elementary preconditioner in combination with a prudent initial estimate usually su ces to reach rapid convergence using the transpose-free quasi-minimal residual method.
Open Access
Least upper bounds of the powers extracted and scattered by bi-anisotropic particles
(IEEE, 2014) Liberal Olleta, Íñigo; Ra'di, Younes; Gonzalo García, Ramón; Ederra Urzainqui, Íñigo; Tretyakov, Sergei A.; Ziolkowski, Richard W.; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
The least upper bounds of the powers extracted and scattered by bi-anisotropic particles are investigated analytically. A rigorous derivation for particles having invertible polarizability tensors is presented, and the particles with singular polarizability tensors that have been reported in the literature are treated explicitly. The analysis concludes that previous upper bounds presented for isotropic particles can be extrapolated to bianisotropic particles. In particular, it is shown that neither nonreciprocal nor magnetoelectric coupling phenomena can further increase those upper bounds on the extracted and scattered powers. The outcomes are illustrated further with approximate circuit model examples of two dipole antennas connected via a generic lossless network.
Open Access
Comparison of modified Soret lenses for dual band integrated detectors
(IEEE, 2020) Torres García, Alicia E.; Pérez Escudero, José Manuel; Gonzalo García, Ramón; Ederra Urzainqui, Íñigo; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
This paper presents the comparison of different modified Soret lenses suitable for a millimeter and submillimeterwave dualband integrated pixel detectors. The approach is based on the modification of a printed planar Soret lens, designed to operate in the sub-mm range, to obtain an antenna at the millimeter region. Three modifications of a transmission-mode Soret Lens at 850 GHz based on spiral, logarithmic and meander antennas geometries have been analyzed with a combination of Kirchhoffs Diffraction and full-wave simulation methods. The performance of the designs has been experimentally demonstrated in the submillimeterwave band, showing good agreement with simulation results.
Open Access
Comparison of a slotted SIW antenna covered with metasurface vs. a traditional array
(IEEE, 2022) Chocarro Álvarez, Javier; Pérez Escudero, José Manuel; Ederra Urzainqui, Íñigo; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute of Smart Cities - ISC; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In this article we compare two solutions to improve the radiation pattern of a slotted Substrate Integrated Waveguide (SIW) antenna: use of an E-plane array and covering it with a metasurface (MTS). To this aim, we compare the changes in performance, radiation pattern and aperture efficiency. We will see the advantages that the metasurface has over the typical array.
Open Access
Grating lobes in higher-order correlation functions of arrays of quantum emitters: directional photon bunching versus correlated directions
(MDPI, 2019) Liberal Olleta, Íñigo; Ederra Urzainqui, Íñigo; Ziolkowski, Richard W.; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
Recent advances in nanofabrication and optical manipulation techniques are making it possible to build arrays of quantum emitters with accurate control over the locations of their individual elements. In analogy with classical antenna arrays, this poses new opportunities for tailoring quantum interference effects by designing the geometry of the array. Here, we investigate the Nth-order directional correlation function of the photons emitted by an array of N initially-excited identical quantum emitters, addressing the impact of the appearance of grating lobes. Our analysis reveals that the absence of directivity in the first-order correlation function is contrasted by an enhanced directivity in the Nth-order one. This suggests that the emitted light consists of a superposition of directionally entangled photon bunches. Moreover, the photon correlation landscape changes radically with the appearance of grating lobes. In fact, the photons no longer tend to be bunched along the same direction; rather, they are distributed in a set of correlated directions with equal probability. These results clarify basic aspects of light emission from ensembles of quantum emitters. Furthermore, they may find applications in the design of nonclassical light sources.
Open Access
Advanced feeds for mm-wave antenna systems
(Springer, 2018) Teniente Vallinas, Jorge; Iriarte Galarregui, Juan Carlos; Ederra Urzainqui, Íñigo; Gonzalo García, Ramón; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Millimeter-wave antenna systems have traditionally required high performance feeds in order to fulfill its stringent requirements. Therefore, this goal has been achieved by corrugated horns. However, in the last years new applications mainly in the communication systems have driven the use of other types of antenna feed with slightly reduced performance but simpler manufacturing at mm-wave and submm-wave frequencies with improvements in cost reduction. These advanced profiles are usually based in smooth waveguide advanced profiles. Besides, the chapter describes different feed configurations based on metamaterial structures and several examples of metamaterial based or inspired antennas are considered. Then, this chapter covers the different alternatives currently used for mm-wave antenna feed: corrugated horns, spline horns, and metamaterial horns. At the end of each section, it includes some research successful results.