Now showing items 1-20 of 20

    • Broadband radar cross-section reduction using AMC technology 

      Iriarte Galarregui, Juan Carlos Upna; Tellechea Pereda, Amagoia Upna; Martínez de Falcón, José Luis Upna; Ederra Urzainqui, Íñigo Upna; Gonzalo García, Ramón Upna; Maagt, Peter de (IEEE, 2013)   Artículo / Artikulua  OpenAccess
      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 ...
    • Circuit and multipolar approaches to investigate the balance of powers in 2D scattering problems 

      Liberal Olleta, Íñigo Upna; Ederra Urzainqui, Íñigo Upna; Gonzalo García, Ramón Upna; Ziolkowski, Richard W. (EMW Publishing, 2013)   Artículo / Artikulua  OpenAccess
      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 ...
    • A comprehensive analysis of the absorption spectrum of conducting ferromagnetic wires 

      Liberal Olleta, Íñigo Upna; Ederra Urzainqui, Íñigo Upna; Gómez Polo, Cristina; Labrador Otamendi, Alberto; Pérez de Landazábal Berganzo, José Ignacio; Gonzalo García, Ramón Upna (IEEE, 2012)   Artículo / Artikulua  OpenAccess
      A detailed analysis of the absorption spectrum of conductive ferromagnetic wires is presented. The absorption spectrum is computed from the solution to the scattering problem, and circuit models are formulated to clarify ...
    • Decoupling of multifrequency dipole antenna arrays for microwave imaging applications 

      Sáenz Sáinz, Elena Upna; Guven, K.; Ozbay, Ekmel; Ederra Urzainqui, Íñigo Upna; Gonzalo García, Ramón Upna (Hindawi Publishing Corporation, 2010)   Artículo / Artikulua  OpenAccess
      The mutual coupling between elements of a multifrequency dipole antenna array is experimentally investigated by S-parameter measurements and planar near-field scanning of the radiated field. A multifrequency array with ...
    • Dispersion properties of an elliptical patch with cross shaped aperture for synchronized propagation of transverse magnetic and electric surface waves 

      Tellechea Pereda, Amagoia Upna; Ederra Urzainqui, Íñigo Upna; Gonzalo García, Ramón Upna; Iriarte Galarregui, Juan Carlos Upna (MDPI, 2018)   Artículo / Artikulua  OpenAccess
      This paper presents a novel pixel geometry for the implementation of metasurfaces requiring synchronized phase propagation of transverse magnetic (TM) and transverse electric (TE) modes. The pixel is composed by an elliptical ...
    • Dual circularly polarized broadside beam metasurface antenna 

      Ederra Urzainqui, Íñigo Upna; Tellechea Pereda, Amagoia Upna; Caminita, Francesco; Martini, Enrica; Iriarte Galarregui, Juan Carlos Upna; Gonzalo García, Ramón Upna; Maci, Stefano (IEEE, 2016)   Artículo / Artikulua  OpenAccess
      This paper presents the design of a modulated metasurface (MTS) antenna capable to provide both righthand (RH) and left-hand (LH) circularly polarized (CP) boresight radiation at Ku-band (13.5 GHz). This antenna is based ...
    • Electromangetic force density in electrically and magnetically polarizable media 

      Liberal Olleta, Íñigo Upna; Ederra Urzainqui, Íñigo Upna; Gonzalo García, Ramón Upna; Ziolkowski, Richard W. (American Physical Society, 2013)   Artículo / Artikulua  OpenAccess
      The force density induced by electromagnetic fields in electrically and magnetically polarizable media is studied analytically. Different formulations of the force density as a function of field-related quantities, ...
    • Evanescently fed electromagnetic band-gap horn antennas and arrays 

      Khromova, Irina Upna; Ederra Urzainqui, Íñigo Upna; Teniente Vallinas, Jorge Upna; Gonzalo García, Ramón Upna; Esselle, Karu P. (IEEE, 2012)   Artículo / Artikulua  OpenAccess
      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 ...
    • Experimental validation of a Ku-band dual circularly polarized metasurface antenna 

      Tellechea Pereda, Amagoia Upna; Caminita, Francesco; Martini, Enrica; Ederra Urzainqui, Íñigo Upna; Teniente Vallinas, Jorge Upna; Iriarte, Juan Carlos; Gonzalo García, Ramón Upna; Maci, Stefano (IEEE, 2018)   Artículo / Artikulua  OpenAccess
      The experimental validation of a Ku-band dual circularly polarized (CP) broadside-beam metasurface (MTS) antenna is presented. A radially modulated anisotropic single layer MTS has been synthesised employing sub-wavelength ...
    • Fe-rich ferromagnetic wires for self-sensing materials 

      Liberal Olleta, Íñigo Upna; Ederra Urzainqui, Íñigo Upna; Gonzalo García, Ramón Upna (IEEE, 2012)   Artículo / Artikulua  OpenAccess
      The possibility of using Fe-rich wires in mechanical stress self-sensing materials is investigated. To this end, a retrieval technique aimed to characterize the high-frequency magnetoimpedance effect in ferromagnetic wires ...
    • Induction theorem analysis of resonant nanoparticles: design of a huygens source nanoparticle laser 

      Liberal Olleta, Íñigo; Ederra Urzainqui, Íñigo Upna; Gonzalo García, Ramón Upna; Ziolkowski, Richard W. (American Physical Society, 2014)   Artículo / Artikulua  OpenAccess
      We propose an advanced formulation of standard antenna theory for the basic investigation and design of resonant nanoparticles. This methodology is based on transforming the original scattering problem into a radiation ...
    • Least upper bounds of the powers extracted and scattered by bi-anisotropic particles 

      Liberal Olleta, Íñigo Upna; Ra´di, Younes; Gonzalo García, Ramón Upna; Ederra Urzainqui, Íñigo Upna; Tretyakov, Sergei A.; Ziolkowski, Richard W. (IEEE, 2014)   Artículo / Artikulua  OpenAccess
      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 ...
    • Magnetic dipole super-resonances and their impact on mechanical forces at optical frequencies 

      Liberal Olleta, Íñigo Upna; Ederra Urzainqui, Íñigo Upna; Gonzalo García, Ramón Upna; Ziolkowski, Richard W. (Optical Society of America, 2014)   Artículo / Artikulua  OpenAccess
      Artificial magnetism enables various transformative optical phenomena, including negative refraction, Fano resonances, and unconventional nanoantennas, beamshapers, polarization transformers and perfect absorbers, and ...
    • A metamaterial T-junction power divider 

      Sáenz Sáinz, Elena Upna; Cantora Álvarez, Alejandro; Ederra Urzainqui, Íñigo Upna; Gonzalo García, Ramón Upna; Maagt, Peter de (IEEE, 2007)   Artículo / Artikulua  OpenAccess
      A metamaterial based compact microstrip T-junction power divider working at 10 GHz is proposed. The metamaterial unit cell consists of microstrip gaps and via holes whose behavior is equivalent to the combination of ...
    • A multipolar analysis of near-field absorption and scattering processes 

      Liberal Olleta, Íñigo Upna; Ederra Urzainqui, Íñigo Upna; Gonzalo García, Ramón Upna; Ziolkowski, Richard W. (IEEE, 2013)   Artículo / Artikulua  OpenAccess
      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 ...
    • Near-field electromagnetic trapping through curl-spin forces 

      Liberal Olleta, Íñigo Upna; Ederra Urzainqui, Íñigo Upna; Gonzalo García, Ramón Upna; Ziolkowski, Richard W. (American Physical Society, 2013)   Artículo / Artikulua  OpenAccess
      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 ...
    • Optimization of a pin surface as a solution to suppress cavity modes in a packaged W-band microstrip receiver 

      Rebollo Mugueta, Ainara Upna; Gonzalo García, Ramón Upna; Ederra Urzainqui, Íñigo Upna (IEEE, 2014)   Artículo / Artikulua  OpenAccess
      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 ...
    • Superbackscattering antenna arrays 

      Liberal Olleta, Íñigo Upna; Ederra Urzainqui, Íñigo Upna; Gonzalo García, Ramón Upna; Ziolkowski, Richard W. (IEEE, 2015)   Artículo / Artikulua  OpenAccess
      This article discusses the theory, design and practical implementation of superbackscattering antenna arrays. In analogy with Uzkov’s maximal directivity theorem, it is demonstrated that the maximal backscattering ...
    • Surface waves of finite size electromagnetic band gap woodpile structures 

      Ederra Urzainqui, Íñigo Upna; Iriarte Galarregui, Juan Carlos Upna; Gonzalo García, Ramón Upna (EMW Publishing, 2011)   Artículo / Artikulua  OpenAccess
      This paper studies the surface modes at the interface of finite size Electromagnetic Band Gap (EBG) woodpile structures. The impact of different types of woodpile terminations on the properties of these surface modes is ...
    • Upper bounds on scattering processes and metamaterial-inspired structures that reach them 

      Ederra Urzainqui, Íñigo Upna; Liberal Olleta, Íñigo Upna; Gonzalo García, Ramón Upna; Ziolkowski, Richard W. (IEEE, 2014)   Artículo / Artikulua  OpenAccess
      The physical limitations on time-harmonic scattering processes are investigated on the basis of the optical theorem. Previously derived least upper bounds on the total scattering and absorption cross-sections are obtained ...