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Zobrazují se záznamy 1-20 z 58

    • A Double H-Shaped Resonator for an Isotropic ENG Metamaterial 

      Autor: Macháč, Jan; Rytíř, Martin; Protiva, Pavel; Zehentner, Jan
      (IEEE, 2008-10)
      This paper presents a new planar particle showing negative effective permittivity under irradiation by an electromagnetic wave. The response of this particle, aimed to be sensitive to an electric field, is strongly ...
    • Coupling of split ring resonators in a mu-negative volumetric metamaterial 

      Autor: Macháč, J.; Zehentner, J.; Bláha, M.
      (IEEE, 2008-06)
      This paper presents an experimental and theoretical study of the coupling of split ring resonators, and aims to show ways to widen the frequency band of the response of mu-negative metamaterials. The behaviour of these ...
    • A Planar Version of A Slotline Leaky Wave Antenna with a Stacked Substrate 

      Autor: Macháč, J.; Pavliš, A.; Houška, M.; Zehentner, J.
      (IEEE, 2008-05)
      This paper presents a new version of a leaky wave antenna based on a conductor-backed slotline with a stacked substrate. The advantage of this new structure is its flat top surface, due to the antenna being fed from the ...
    • A Simple Ultra-Wideband Suspended Stripline Bandpass Filter With Very Wide Stop-Band 

      Autor: Balalem, Atallah; Menzel, Wolfgang; Macháč, Jan; Omar, Abbas
      (IEEE, 2008-03)
      This letter introduces a simple ultra-wideband suspended stripline filter with a pass-band from 3.1 to 10.6 GHz and a very wide stop-band up to more than 25 GHz. The filter is realized by capacitive coupling of a quasi-lumped ...
    • Microwave reflectivity from gold sputtered nanolayer 

      Autor: Buchar, Pavel; Macháč, Jan; Zehentner, Ján
      (IEEE, 2007-11)
      This paper deals with reflectivity of a gold layer of nanometer-scale thickness sputtered on a dielectric foil at microwave frequencies. A model of nanometer-scale spheres characterizes the behavior of the layer. For short ...
    • Novel Entire Top Surface Planar Leaky Wave Antenna 

      Autor: Zehentner, Ján; Macháč, Jan; Zabloudil, Pavel
      (IEEE, 2007-10)
      This paper presents the application of a flat waveguide with a longitudinal slot in the middle of its wider wall for the design of a leaky wave antenna. The antenna is fed from a coaxial connector on its bottom, and provides ...
    • Triple Wire Medium for Use in Isotropic Metamaterials 

      Autor: Hudlička, Martin; Macháč, Jan
      (IEEE, 2007-10)
      In this paper a triple wire medium is described as an isotropic negative permittivity medium. A numerical experiment was performed to validate the propagation of electromagnetic waves inside the wire lattice below the ...
    • Isotropic Epsilon-Negative Particles 

      Autor: Macháč, Jan; Protiva, Pavel; Zehentner, Ján
      (IEEE, 2007-06)
      This paper presents two particles with negative permittivity in some frequency band. The response of a single dipole loaded by an inductance is strongly anisotropic. The response of a spider dipole does not depend on the ...
    • Reflection from a Gold Sputtered Thin Layer 

      Autor: Buchar, Pavel; Macháč, Jan; Zehentner, Ján; Slepička, Petr; Švorčík, Václav
      (IEEE, 2006-05)
      This paper presents the results of an investigation of a thin layer of gold sputtered on a dielectric foil. This layer is modeled by nanometer-scale spherical particles that are separated at short deposition times and later ...
    • Low Profile Slotted Flat Waveguide Leaky Wave Antenna 

      Autor: Zehentner, Ján; Macháč, Jan; Zabloudil, Pavel
      (IEEE, 2006-06)
      This paper presents the application of a flat waveguide with a longitudinal slot in the middle of its wider wall for the design of a leaky wave antenna. The antenna radiates into one relatively narrow main beam and its ...
    • Bandpass Filters on a Modified Multilayer Coplanar Line 

      Autor: Balalem, Atallah; Hamad, Ehab K. I.; Macháč, Jan; Omar, Abbas S.
      (IEEE, 2006-06)
      The design of compact multilayer coplanar line bandpass filters is presented. These very compact filters make use of the two sides of the substrate of the modified coplanar line. In addition, a transmission zero has been ...
    • Microstrip Line on an Artificial Dielectric Substrate 

      Autor: Macháč, Jan
      (IEEE, 2006-07)
      This letter presents a new version of an artificial dielectric substrate and a microstrip line built on top of this substrate. The substrate is fabricated as a two-dimensional array of metallic posts separated from the top ...
    • Use of Nano-Grids in a Waveguide 

      Autor: Zehentner, Ján; Macháč, Jan; Zabloudil, Pavel
      (IEEE, 2006-09)
      A new concept of passive waveguide circuits is presented. It is based on a combination of the standard rectangular waveguide with a metal uniform linear polarization grid of nano thickness. The grid is deposited on a polymer ...
    • Power Control in Passive Waveguide Circuits 

      Autor: Zehentner, Ján; Macháč, Jan; Zabloudil, Pavel
      (IEEE, 2006-12)
      A new concept of a passive waveguide reflection attenuator and a T-junction with a variable ratio of the output powers is reported here. A conductive uniform linear polarization grid of nano thickness is inserted into the ...
    • Quasi-Elliptic Microstrip Low-Pass Filters Using an Interdigital DGS Slot 

      Autor: Balalem, Atallah; Ali, Ali R.; Macháč, Jan; Omar, Abbas
      (IEEE, 2007-08)
      This letter introduces a DGS slot with an interdigital shape. The resonant frequency of the slot can be easily controlled by changing the length of the metal fingers, without changing the area taken by the structure. Using ...
    • Coplanar Waveguide Transmitting a Left-Handed Wave 

      Autor: Macháč, Jan; Hudlička, Martin; Zehentner, Ján; Spiliotis, Nikolaos G.; Omar, Abbas S.
      (IEEE, 2005-10)
      This paper presents a new version of a coplanar waveguide that transmits a left-handed wave. The equivalent circuit of the line unit cell has been derived from the shape of the layout. The values of its elements were ...
    • Left-Handed Coplanar Waveguide 

      Autor: Macháč, Jan; Hudlička, Martin; Zehentner, Ján; Spiliotis, Nikolaos G.; Omar, Abbas S.
      (IEEE, 2005-06)
      This paper proposes a new version of a left-handed coplanar waveguide. The line has a fully uniplanar structure without vias and lumped elements. The series capacitors are represented by interdigital capacitors and the ...
    • New Bulk Metamaterial 

      Autor: Macháč, Jan; Buchar, Pavel; Zehentner, Ján; Omar, Abbas S.
      (IEEE, 2005-10)
      The design, analysis, fabrication and measurement of a new bulk metamaterial is reported in this paper. The structure of the new medium is made up of left-handed parallel strips. The series capacitors are realized by short ...
    • Planar Transmission Lines in MW and MMW Circuits 

      Autor: Zehentner, Ján; Macháč, Jan; Mrkvica, Jan
      (IEEE, 2005-09)
      The analysis of open, particularly slotted planar transmission lines in a wide frequency range is presented in this paper. The full wave approach by the spectral domain method is applied. Theoretical findings and their ...
    • Flat Waveguide with a Longitudinal Slot 

      Autor: Zehentner, Ján; Mrkvica, Jan; Macháč, Jan
      (IEEE, 2005-06)
      This paper presents an analysis of a flat slotted waveguide by the spectral domain method finalized by a complex root search procedure. Matching of fields from bounded and unbounded regions at the common interface is ...