• A dual band circularly polarized antenna based on a microstrip patch filled with left-handed structures 

      Herraiz Martínez, Francisco Javier; González Posadas, Vicente; Segovia Vargas, Daniel (Sin editorial (Edimburgo, Reino Unido), 11/11/2007)
      Microstrip patches filled with left-handed structures are proposed to obtain dual band circularly polarized antennas. The proposed antennas have two modes at different frequencies with similar characteristics to the ...
    • A passive temperature sensor based on a printed magnetoinductive-wave (MIW) delay line 

      Herraiz Martínez, Francisco Javier; Martínez Cebrián, Javier; Segovia Vargas, Daniel (Sin editorial (París, Francia), 06/09/2015)
      Novel fully passive and electromagnetic sensors are proposed. These sensors are implemented with magnetoinductive-wave (MIW) delay lines. Such lines are composed of a periodic array of coupled square split ring resonators ...
    • Application of the left-handed half-ioop antenna with wideband tuning to a cognitive radio terminal 

      Herraiz Martínez, Francisco Javier; Hall, Peter S.; Segovia Vargas, Daniel (Sin editorial (Barcelona, España), 12/04/2010)
      A compact system for future communication terminals (Cognitive Radio) is presented in this paper. This system is based on two antennas printed on the same substrate board. The total dimensions of the board are 60 mm × 60 ...
    • Arrays of dual-band printed dipoles loaded with metamaterial particles 

      Herraiz Martínez, Francisco Javier; García Muñoz, Luis Enrique; Segovia Vargas, Daniel; González Ovejero, David; Craeye, Christophe (Sin editorial (Berlín, Alemania), 23/03/2009)
      Arrays of printed dipoles loaded with metamaterial particles are presented in this paper. The use of these loaded dipoles can improve the features of the arrays. Two applications are proposed: the miniaturization of the ...
    • Chipless RFID system based on magnetoinductive-wave (MIW) delay lines 

      Herraiz Martínez, Francisco Javier; Ugarte Muñoz, Eduardo; Segovia Vargas, Daniel; Paredes Marco, Ferran; Zamora González, Gerard; Martín Antolín, Ferran; Bonache Albacete, Jordi (Sin editorial (Nagoya, Japón), 29/10/2012)
      A novel fully passive and electromagnetic chipless radiofrequency identification (RFID) system is proposed. The system is based on printed tags implemented with magnetoinductive-wave (MIW) delay lines. Such lines are ...
    • Chipless RFID tags based on magneto-inductive or electro-inductive delay lines 

      Herraiz Martínez, Francisco Javier; González Moreno, Alvaro; Segovia Vargas, Daniel (Sin editorial (Dubrovnik, Croacia), 14/10/2013)
      Novel fully passive and electromagnetic chipless tags are proposed. These tags are implemented with magnetoinductive-wave (MIW) delay lines. Such lines are composed of a periodic array of coupled square split ring resonators ...
    • 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). ...
    • Design techniques for circularly polarized antennas using metamaterial structures 

      Ugarte Muñoz, Eduardo; Herraiz Martínez, Francisco Javier; González Posadas, Vicente; García Muñoz, Luis Enrique; Segovia Vargas, Daniel (Sin editorial (Roma, Italia), 29/09/2009)
      In this paper four multi-frequency circularly polarized antennas are proposed. The first one is a 4-ports self-diplexed multi-frequency RHCP-LHCP antenna. The second antenna is a single-feed short-circuited circular patch ...
    • Dual-frequency printed dipole loaded with metamaterial particles 

      Herraiz Martínez, Francisco Javier; Segovia Vargas, Daniel; García Muñoz, Luis Enrique; González Posadas, Vicente (Sin editorial (San Diego, Estados Unidos de América), 05/07/2008)
      In this paper a dual-frequency printed dipole is presented. This antenna is made by loading a dipole printed on both sides of a FR-4 substrate with metamaterial resonant particles. First, a simplified model based on a ...
    • 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 ...
    • Dyson conical quad-spiral array for VLBI2010 

      Rivera Lavado, Alejandro; Llorente Romano, Sergio; Herraiz Martínez, Francisco Javier; García Muñoz, Luis Enrique; López Fernández, Jose Antonio; López Pérez, Jose Antonio; Tercero Martínez, Felix; Segovia Vargas, Daniel (Sin editorial (La Haya, España), 06/04/2014)
      A new topology that potentially can open new solutions for covering the new VLBI2010 configuration and its frequency bands associated is presented in this manuscript. In this approach a single band from 2 to 14 GHz is ...
    • 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 ...
    • Hexagonal metallo-dielectric periodic structure: characterization and application 

      Segovia Vargas, Daniel; Herraiz Martínez, Francisco Javier; Iñigo Villacorta, Fernando; González Posadas, Vicente (Sin editorial (Edimburgo, Reino Unido), 11/11/2007)
      A hexagonal metallo-dielectric periodic structure is studied to see the propagation modes in the pass bandwidth. The pass bandwidth is constituted by several resonances that are not associated to the same propagation mode. ...
    • 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 ...
    • Multi-frequency microstrip patch antennas based on metamaterial structures 

      Herraiz Martínez, Francisco Javier; González Posadas, Vicente; Segovia Vargas, Daniel (Sin editorial (Honolulu, Estados Unidos de América), 09/06/2007)
      In this paper, CRLH TL based antennas and microstrip patches concepts are merged to design multi-frequency antennas. The proposed antenna works at four different frequencies with non-whole ratio between them. This is ...
    • Multi-frequency printed dipoles loaded with metamaterial particles 

      Herraiz Martínez, Francisco Javier; García Muñoz, Luis Enrique; González Posadas, Vicente; Segovia Vargas, Daniel (Sin editorial (Praga, República Checa), 23/04/2008)
      Multi-frequency printed dipoles based on antipodal printed dipoles loaded with metamaterial particles are presented. Split ring resonators (SRRs) are used as metamaterial particles in order to obtain fully printed and ...
    • 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)