Now showing items 41-58 of 58

    • New Bulk Metamaterial 

      Author: 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 ...
    • Reflection from a Gold Sputtered Thin Layer 

      Author: 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 

      Author: 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 

      Author: 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 

      Author: 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 

      Author: 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 

      Author: 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 ...
    • Isotropic Epsilon-Negative Particles 

      Author: 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 ...
    • Quasi-Elliptic Microstrip Low-Pass Filters Using an Interdigital DGS Slot 

      Author: 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 ...
    • Novel Entire Top Surface Planar Leaky Wave Antenna 

      Author: 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 

      Author: 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 ...
    • Microwave reflectivity from gold sputtered nanolayer 

      Author: 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 ...
    • A Simple Ultra-Wideband Suspended Stripline Bandpass Filter With Very Wide Stop-Band 

      Author: 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 ...
    • Evaluation and Correction of Cable Phase Stability in High Frequency Near-Field Measurement 

      Author: Vancl, Jan; Černý, Petr; Škvor, Zbyněk; Mazánek, Miloš
      (IEEE, 2008-04)
      In case of the near-field measurement, the radiated field by the measured antenna is received by two- dimensional scanner in defined points. During the process of the field scanning, the cable between the VNA and the scanner ...
    • A Planar Version of A Slotline Leaky Wave Antenna with a Stacked Substrate 

      Author: 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 ...
    • Coupling of split ring resonators in a mu-negative volumetric metamaterial 

      Author: 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 Double H-Shaped Resonator for an Isotropic ENG Metamaterial 

      Author: 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 ...
    • Hidden Problems in Precise Calibration on Microstrip 

      Author: Raboch, Jiří; Hoffmann, Karel; Škvor, Zbyněk; Hudec, Přemysl
      (IEEE, 2008-12)
      A study of calibration problems on microstrip with respect to interaction of electromagnetic fields around SMA to microstrip launcher and microstrip short was carried out in frequency band up to 26 GHz. Omni Spectra SMA ...