Now showing items 1-19 of 19

    • 77-GHz high-gain bull’s-eye antenna with sinusoidal profile 

      Beaskoetxea Gartzia, Unai Upna Orcid; Pacheco-Peña, Víctor Upna Orcid; Orazbayev, Bakhtiyar Upna Orcid; Akalin, Tahsin; Maci, Stefano; Navarro Cía, Miguel Upna Orcid (IEEE, 2015)   Artículo / Artikulua  OpenAccess
      A high-gain Bull’s-Eye leaky-wave horn antenna working at 77 GHz with sinusoidal profile has been designed, fabricated, and experimentally measured. The influence of the number of periods on the gain and beamwidth is ...
    • Advanced metamaterials for high resolution focusing and invisibility cloaks 

      Orazbayev, Bakhtiyar Upna Orcid (2016)   Tesis doctoral / Doktoretza tesia  OpenAccess
      Los metamateriales, descendientes de los dieléctricos artificiales, tienen parámetros electromagnéticos inusuales y proporcionan más posibilidades que los dieléctricos naturales para el control de la propagación de la luz. ...
    • All-metallic ε-near-zero (ENZ) lens based on ultra-narrow hollow rectangular waveguides: experimental results 

      Orazbayev, Bakhtiyar Upna Orcid; Torres Landívar, Víctor Upna; Pacheco-Peña, Víctor Upna Orcid; Falcone Lanas, Francisco Javier Upna Orcid; Teniente Vallinas, Jorge Upna Orcid; Beruete Díaz, Miguel Upna Orcid; Sorolla Ayza, Mario Upna; Navarro Cía, Miguel Upna Orcid; Engheta, Nader (IEEE, 2014)   Contribución a congreso / Biltzarrerako ekarpena  OpenAccess
      Here we perform numerical and experimental investigation of plano-concave all-metallic ε-near-zero (ENZ) lens with operational frequency f = 144 GHz. The ENZ lens is achieved by stacking an array of narrow hollow rectangular ...
    • Diffusive-light invisibility cloak for transient illumination 

      Orazbayev, Bakhtiyar Upna Orcid; Beruete Díaz, Miguel Upna Orcid; Martínez, Alejandro; García Meca, Carlos (American Physical Society, 2016)   Artículo / Artikulua  OpenAccess
      Invisibility in a diffusive-light-scattering medium has been recently demonstrated by employing a scattering-cancellation core-shell cloak. Unlike nondiffusive cloaks, such a device can be simultaneously macroscopic, ...
    • Experimental demonstration of a millimeter-wave metallic ENZ lens based on the energy squeezing principle 

      Torres Landívar, Víctor Upna; Orazbayev, Bakhtiyar Upna Orcid; Pacheco-Peña, Víctor Upna Orcid; Teniente Vallinas, Jorge Upna Orcid; Beruete Díaz, Miguel Upna Orcid; Navarro Cía, Miguel Upna Orcid; Sorolla Ayza, Mario Upna (IEEE, 2015)   Artículo / Artikulua  OpenAccess
      The performance of an epsilon-near zero (ENZ) plano-concave lens is experimentally demonstrated and verified at the D-band of the millimeter-waves. The lens is comprised of an array of narrow metallic waveguides near cut-off ...
    • Experimental demonstration of metasurface-based ultrathin carpet cloaks for millimetre waves 

      Orazbayev, Bakhtiyar Upna Orcid; Mohammadi Estakhri, Nasim; Alù, Andrea; Beruete Díaz, Miguel Upna Orcid (Wiley, 2016)   Artículo / Artikulua  OpenAccess
      A metasurface carpet cloak for millimeter-wave range with polarization-independent performance is experimentally demonstrated. It is shown that the cloak is able to mimic the ground plane by fully restoring the amplitude ...
    • Exploiting the dispersion of the double-negative-index fishnet metamaterial to create a broadband low-profile metallic lens 

      Orazbayev, Bakhtiyar Upna Orcid; Pacheco-Peña, Víctor Upna Orcid; Beruete Díaz, Miguel Upna Orcid; Navarro Cía, Miguel Upna Orcid (Optical Society of America, 2015)   Artículo / Artikulua  OpenAccess
      Metamaterial lenses with close values of permittivity and permeability usually display low reflection losses at the expense of narrow single frequency operation. Here, a broadband low-profile lens is designed by exploiting ...
    • Mechanical 144GHz beam steering with all-metallic epsilon-near-zero lens antenna 

      Pacheco-Peña, Víctor Upna Orcid; Torres Landívar, Víctor Upna; Orazbayev, Bakhtiyar Upna Orcid; Beruete Díaz, Miguel Upna Orcid; Navarro Cía, Miguel Upna Orcid; Sorolla Ayza, Mario Upna; Engheta, Nader (AIP Publishing, 2014)   Artículo / Artikulua  OpenAccess
      An all-metallic steerable beam antenna composed of an ε-near-zero (ENZ) metamaterial lens is experimentally demonstrated at 144 GHz (λ0 = 2.083 mm). The ENZ lens is realized by an array of narrow hollow rectangular waveguides ...
    • Metasurface-based ultrathin carpet cloaks for millimeter waves 

      Orazbayev, Bakhtiyar Upna Orcid; Mohammadi Estakhri, Nasim; Alù, Andrea; Beruete Díaz, Miguel Upna Orcid (2017)   Artículo / Artikulua  OpenAccess
      A metasurface carpet cloak for millimetre-wave range with polarization independent performance is experimentally demonstrated. It is shown that the cloak is able to mimic the ground plane by fully restoring the amplitude ...
    • Soret fishnet metalens antenna 

      Orazbayev, Bakhtiyar Upna Orcid; Beruete Díaz, Miguel Upna Orcid; Pacheco-Peña, Víctor Upna Orcid; Crespo López, Gonzalo Upna; Teniente Vallinas, Jorge Upna Orcid; Navarro Cía, Miguel Upna Orcid (Springer Nature, 2015)   Artículo / Artikulua  OpenAccess
      At the expense of frequency narrowing, binary amplitude-only diffractive optical elements emulate refractive lenses without the need of large profiles. Unfortunately, they also present larger Fresnel reflection loss ...
    • Terahertz carpet cloak based on a ring resonator metasurface 

      Orazbayev, Bakhtiyar Upna Orcid; Mohammadi Estakhri, Nasim; Beruete Díaz, Miguel Upna Orcid; Alù, Andrea (American Physical Society, 2015)   Artículo / Artikulua  OpenAccess
      In this work we present the concept and design of an ultrathin (λ/22) terahertz (THz) unidirectional carpet cloak based on the local phase compensation approach enabled by gradient metasurfaces. A triangular surface bump ...
    • Tripod-loop metasurfaces for terahertz-sensing applications: a comparison 

      Jáuregui López, Irati Upna Orcid; Orazbayev, Bakhtiyar Upna Orcid; Pacheco-Peña, Víctor Upna Orcid; Beruete Díaz, Miguel Upna Orcid (MDPI, 2020)   Artículo / Artikulua  OpenAccess
      The high electric field intensity achieved on the surface of sensors based on metasurfaces (metasensors) makes them an excellent alternative for sensing applications where the volume of the sample to be identified is tiny ...
    • Tunable beam steering enabled by graphene metamaterials 

      Orazbayev, Bakhtiyar Upna Orcid; Beruete Díaz, Miguel Upna Orcid; Khromova, Irina Upna Orcid (Optical Society of America, 2016)   Artículo / Artikulua  OpenAccess
      We demonstrate tunable mid-infrared (MIR) beam steering devices based on multilayer graphene-dielectric metamaterials. The effective refractive index of such metamaterials can be manipulated by changing the chemical potential ...
    • Ultra-compact planoconcave zoned metallic lens based on the fishnet metamaterial 

      Pacheco-Peña, Víctor Upna Orcid; Orazbayev, Bakhtiyar Upna Orcid; Torres Landívar, Víctor Upna; Beruete Díaz, Miguel Upna Orcid; Navarro Cía, Miguel Upna Orcid (AIP Publishing, 2013)   Artículo / Artikulua  OpenAccess
      A 1.5λ0 -thick planoconcave zoned lens based on the fishnet metamaterial is demonstrated experimentally at millimeter wavelengths. The zoning technique applied allows a volume reduction of 60% compared to a full fishnet ...
    • Ultrathin and high-efficiency Pancharatnam-Berry phase metalens for millimeter waves 

      Moreno-Peñarrubia, Alexia; Teniente Vallinas, Jorge Upna Orcid; Kuznetsov, Sergei A.; Orazbayev, Bakhtiyar Upna Orcid; Beruete Díaz, Miguel Upna Orcid (AIP Publishing, 2021)   Artículo / Artikulua  OpenAccess
      Applying the Pancharatnam–Berry (PB) principle to half-wave plate (HWP) metasurfaces allows the manipulation of wavefronts along with the conversion of the handedness of circularly polarized incident waves by simply rotating ...
    • Wideband backscattering reduction at terahertz using compound reflection grating 

      Orazbayev, Bakhtiyar Upna Orcid; Rodríguez Ulibarri, Pablo Upna Orcid; Beruete Díaz, Miguel Upna Orcid (Optical Society of America, 2017)   Artículo / Artikulua  OpenAccess
      Backscattering reduction is usually achieved by using either absorbers or diffractions gratings at the expense of a narrow bandwidth. In this paper, we propose a different strategy based on a metallic compound reflection ...
    • Wood zone plate fishnet metalens 

      Orazbayev, Bakhtiyar Upna Orcid; Beruete Díaz, Miguel Upna Orcid; Navarro Cía, Miguel Upna Orcid (EDP Sciences, 2015)   Artículo / Artikulua  OpenAccess
      Fresnel-zone plate lenses provide focusing performance while having low profile. Unfortunately, they usually display higher reflection losses than conventional dielectric lenses. Here, we demonstrate a low-profile Wood ...
    • Zoned fishnet lens antenna with reference phase for side lobe reduction 

      Pacheco-Peña, Víctor Upna Orcid; Navarro Cía, Miguel Upna Orcid; Orazbayev, Bakhtiyar Upna Orcid; Minin, Igor V.; Minin, Oleg V.; Beruete Díaz, Miguel Upna Orcid (IEEE, 2015)   Artículo / Artikulua  OpenAccess
      Reduction of first side lobe level and nulls in artificial fishnet metalenses is accomplished here by applying the reference phase concept along with the zoning technique. Higher focusing efficiency is achieved for a ...
    • Zoned near-zero refractive index fishnet lens antenna: steering millimeter waves 

      Pacheco-Peña, Víctor Upna Orcid; Orazbayev, Bakhtiyar Upna Orcid; Beaskoetxea Gartzia, Unai Upna Orcid; Beruete Díaz, Miguel Upna Orcid; Navarro Cía, Miguel Upna Orcid (AIP Publishing, 2014)   Artículo / Artikulua  OpenAccess
      A zoned fishnet metamaterial lens is designed, fabricated, and experimentally demonstrated at millimeter wavelengths to work as a negative near-zero refractive index lens suitable for compact lens antenna configurations. ...