Now showing items 1-17 of 17

    • Design method for actively matched antennas with non-foster elements 

      Albarracín Vargas, Fernando; González Posadas, Vicente; Herraiz Martínez, Francisco Javier; Segovia Vargas, Daniel (01/09/2016)
      The design of electrically small antennas (ESAs) loaded with active non-Foster elements is a topic whose interest has grown in the last years. In this communication, a new strategy for the design of actively matched antennas ...
    • Design of dual-frequency SRR-loaded dipole with equivalent circuit approach 

      González Posadas, Vicente; Jiménez Martín, Jose Luís; Herraiz Martínez, Francisco Javier; García Muñoz, Luis Enrique; Segovia Vargas, Daniel (10/09/2009)
      An equivalent circuit approach to design dual-frequency printed dipoles is presented. This approach is based on magnetic coupled circuit characterising an antipodal printed dipole loaded with split ring resonators (SRRs). ...
    • Dual-frequency printed dipole loaded with split ring resonators 

      Herraiz Martínez, Francisco Javier; García Muñoz, Luis Enrique; González Ovejero, David; González Posadas, Vicente; Segovia Vargas, Daniel (09/01/2009)
      A novel approach to design dual-frequency printed dipoles is presented. This approach is based on an antipodal printed dipole loaded with split ring resonators (SRRs). This technique allows the choice of any pair of working ...
    • Filtering lens structure based on SRRs in the low THz band 

      Andrés García, Belén; García Muñoz, Luis Enrique; González Posadas, Vicente; Herraiz Martínez, Francisco Javier; Segovia Vargas, Daniel (01/05/2009)
      A filtering lens for conical horns based on Metamaterials is presented. The paper focuses on a millimeter wave application. The metamaterial structure is composed of a printed layer of Split Ring Resonators (SRRs) on a ...
    • Left-handed wire antennas over ground plane with wideband tuning 

      Herraiz Martínez, Francisco Javier; Hall, Peter S.; Liu, Qing; Segovia Vargas, Daniel (01/05/2011)
      Tunable left-handed (LH) wire antennas over a ground plane are presented in this paper. These antennas are small and have a wide tuning bandwidth and are matched to 50 ? within the operation range. Two kinds of antennas ...
    • Low-cost approach based on an eigenfrequency method to obtain the dispersion diagram in CRLH structures 

      Herraiz Martínez, Francisco Javier; González Posadas, Vicente; Iñigo Villacorta, Fernando; Segovia Vargas, Daniel (08/01/2007)
      A novel method to obtain the dispersion diagram of a composite right/left-handed (CRLH) unit-cell is presented. This method is based on CRLH transmission-line (TL) theory and on the structure eigenfrequencies. First, it ...
    • Multi-frequency and dual mode patch antennas partially filled with left-handed structures 

      Herraiz Martínez, Francisco Javier; González Posadas, Vicente; García Muñoz, Luis Enrique; Segovia Vargas, Daniel (05/08/2008)
      Multifrequency microstrip patch antennas partially filled with left-handed (LH) structures are presented. The presence of LH structures also enables miniaturized antennas. Thus, multifrequency, dual-mode, and miniaturized ...
    • Multifrequency and multifunction metamaterial-loaded printed antennas 

      Herraiz Martínez, Francisco Javier; Segovia Vargas, Daniel; Ugarte Muñoz, Eduardo; García Muñoz, Luis Enrique; González Posadas, Vicente (InTech Europe (Rijeka, Croacia), 01/04/2010)
    • Multifrequency printed antennas loaded with metamaterial particles 

      Segovia Vargas, Daniel; Herraiz Martínez, Francisco Javier; Ugarte Muñoz, Eduardo; Montero de Paz, Javier; González Posadas, Vicente; García Muñoz, Luis Enrique (01/06/2009)
      This paper provides a review of printed antennas loaded with metamaterial particles. This novel technique allows developing printed antennas with interesting features such as multifrequency (simultaneous operation over two ...
    • Multifrequency self-diplexed single patch antennas loaded with split ring resonators 

      Montero de Paz, Javier; Ugarte Muñoz, Eduardo; Herraiz Martínez, Francisco Javier; González Posadas, Vicente; García Muñoz, Luis Enrique; Segovia Vargas, Daniel (01/03/2011)
      In this paper a novel approach to design multifrequency self-diplexed single patch antennas is proposed. This approach is based on a square microstrip patch antenna loaded with split ring resonators (SRRs). The working ...
    • Patch antenna based on metamaterials for a RFID transponder 

      Ugarte Muñoz, Eduardo; Herraiz Martínez, Francisco Javier; González Posadas, Vicente; Segovia Vargas, Daniel (01/06/2008)
      In this paper a self-diplexed antenna is proposed for a RFID transponder application. The development cycle is divided into two stages: antenna design and filters design. The antenna is based on a square microstrip patch ...
    • Planar superstrate for dual-frequency RHCP-LHCP array 

      Ugarte Muñoz, Eduardo; Herraiz Martínez, Francisco Javier; Montero de Paz, Javier; García Muñoz, Luis Enrique; Segovia Vargas, Daniel (01/06/2011)
      Patch antennas are low profile, lightweight and most suitable for aerospace and mobile applications. In recent years Fabry-Pérot cavities and meta-surfaces have been used as superstrates to improve the radiation performance ...
    • Quad-frequency linearly-polarized and dual-frequency circularly-polarized microstrip patch antennas with CRLH loading 

      Segovia Vargas, Daniel; Herraiz Martínez, Francisco Javier; Ugarte Muñoz, Eduardo; García Muñoz, Luis Enrique; González Posadas, Vicente (01/01/2013)
      In this paper, a novel technique to develop multifrequency microstrip patch antennas with polarization diversity or circular polarization is presented. The proposed approach consists of exciting modes with orthogonal ...
    • Self-diplexed patch antennas based on metamaterials for active RFID systems 

      Herraiz Martínez, Francisco Javier; Ugarte Muñoz, Eduardo; González Posadas, Vicente; García Muñoz, Luis Enrique; Segovia Vargas, Daniel (01/05/2009)
      This paper presents a full duplex active RF identification system with arbitrary values for any of the two frequencies in the different radio links. First, the antennas proposed in this paper are based on linearly polarized ...
    • Small printed log-periodic array, matched with an active non-foster network 

      Albarracín Vargas, Fernando; Herraiz Martínez, Francisco Javier; Segovia Vargas, Daniel
      The design of a small printed-log-periodic antenna, loaded with an active matching network, for multiband applications is presented. A well-known, low-cost and low-profile antenna is re-engineered for including an additional ...
    • Split-ring resonator-based sensor for thin-film sensing applications 

      Galindo Romera, Gabriel; Herraiz Martínez, Francisco Javier; Gil Barba, Marta; Martínez Martínez, José Juan; Segovia Vargas, Daniel
      A Split-Ring Resonator (SRR) based sensor for the detection of solid thickness is proposed. The structure is composed by a host microstrip transmission line loaded with two SRRs. The sensing principle is based on the ...
    • Submersible printed split-ring resonator -based sensor for thin-film detection and permittivity characterization 

      Galindo Romera, Gabriel; Herraiz Martínez, Francisco Javier; Martínez Martínez, José Juan; Segovia Vargas, Daniel (15/05/2016)
      A split-ring resonator (SRR)-based sensor for the detection of solid thickness and relative permittivity characterization of solid and liquid materials is proposed. The structure is composed of two SRRs hosted in a microstrip ...