• 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 ...
    • New Space Leaky Wave Spectrum Components on the Slotline 

      Autor: Zehentner, Ján; Macháč, Jan
      (IEEE, 2000-10)
      Surface and space leakage of power deteriorates the operation of circuits. On the other hand space leaky waves enable the design of specific radiators. In this paper we therefore investigate the potential of the slotline ...
    • 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 ...
    • Novel Selected Modes on the Conductor - Backed Slotline 

      Autor: Zehentner, Ján; Macháč, Jan; Mrkvica, Jan
      (IEEE, 2002)
      This paper presents a detailed full-wave analysis of the conductor-backed slotline. The occurrence of an even dominant mode is revealed. This mode may propagate alone from dc up to the frequency at which the first leaky ...
    • On radio interference filter measurement 

      Autor: Hoffmann, Karel; Škvor, Zbyněk
      (IEEE, 2003-12)
      A new measurement method for on site testing of multiport radio interference filters (RIF) on shielded chamber is designed. The method is based on scalar measurement only and makes possible a pessimistic estimate of the ...
    • On the design of waveguide-to-microstrip and waveguide-to-coplanar line transitions 

      Autor: Macháč, Jan; Menzel, Wolfgang
      (IEEE, 1993-09)
      New versions of the waveguide-to-microstrip and waveguide-to-coplanar line transitions are described and analyzed. The transitions differ from the standard ones by a probe in the shape of a rectangular patch. The structure ...
    • Performance of the slotline in the mm-wave range 

      Autor: Zehentner, Ján; Macháč, Jan; Migliozzi, Maurizio
      (IEEE, 1998-05)
      This paper deals with an investigation of the dispersion characteristics of the slotline in the mm-wave range. Attention is paid to the possible excitation of the surface leaky waves on the slotline. Higher order leaky ...
    • Planar Slot-Patch Antenna 

      Autor: Zehentner, Ján; Macháč, Jan; Lorenz, Petr; Mrkvica, Jan
      (IEEE, 2001-09)
      This paper discusses investigations of leaky wave radiation from the slotline made on a low permittivity substrate. New findings on the field distribution of the space leaky wave propagating on a slotline with a wide slot ...
    • 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 ...
    • 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 ...
    • Properties of CPW in the sub-mm wave range and its potential to radiate 

      Autor: Zehentner, J.; Macháč, J.
      (IEEE, 2000)
    • 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 ...
    • 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 ...
    • Short and Open Circuited Slot Line 

      Autor: Macháč, Jan; Zehentner, Ján; Menzel, Wolfgang
      (IEEE, 1995-07)
      A slot line terminated by the short and open end is analysed by the spectral domain method (SDM). The original process of Yang and Alexopoulos (1988) is modified by application of the piecewise sinusoidal functions only. ...
    • Space Leakage of Power from the Slotline 

      Autor: Zehentner, Ján; Macháč, Jan; Lorenz, Petr
      (IEEE, 2001)
      In this paper we present the comprehensive dispersion characteristics of the slotline on thin and low permittivity substrate with a wide slotwidth comprising the bound and space leaky waves with even and odd electric field ...
    • Space leakage of power from uniplanar transmission lines 

      Autor: Macháč, Jan; Zehentner, Ján
      (IEEE, 2000)
      Surface and space leakage of power deteriorates the operation of circuits. On the other hand space leaky waves enable the design of specific radiators. We therefore investigate the potential of the slotline and the coplanar ...
    • Spurious leaky mode solutions and experimental verification of the second leaky wave 

      Autor: Zehentner, J.; Macháč, J.; Mrkvica, J.; Vacek, P.; Polívka, J.
      (IEEE, 1999)
      This paper presents the revelation of spurious leaky mode solutions of the dispersion equation, and experimental confirmation of the occurrence of the second leaky wave on the slotline. The appearance of the spurious ...
    • Stability of FDTD in Curvilinear Coordinates 

      Autor: Pauk, Lukáš; Škvor, Zbyněk
      (IEEE, 2001-07)
      A new approach suitable for determination of the maximal stable time step for the finite-difference time domain (FDTD) algorithm in curvilinear coordinates is presented. It is based on a modified variable separation method, ...
    • Static model of DH laser 

      Autor: Macháč, J.
      (IEEE, 1983-04)
      A method of complex analysis of the double-heterostructure stripe-geometry laser, based on a new static model, is presented. The optical field distribution in the active region of the laser is described by the wave equation. ...
    • Surface leaky waves and their measurement 

      Autor: Zehentner, Ján; Macháč, Jan; Mrkvica, Jan; Sarnowski, Marcin K.; Polívka, Jiří
      (IEEE, 1998-10)
      A new approach to experimental identification of surface leaky waves on printed-circuit lines is presented in this paper. Active radiometry is used for field probing even in the near field zone. The measurement is adjusted ...