• 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 ...
    • The Distributed Oscillator at 4 GHz 

      Autor: Divina, Lukáš; Škvor, Zbyněk
      (IEEE, 1998-12)
      This paper describes the design and experimental verification of a tunable oscillator based on a microwave distributed amplifier. The oscillator met design expectations, being capable of continuous tuning over the range ...
    • The Inverted Conductor-Backed Slotline - a Challenge to Antenna and Circuit Design 

      Autor: Zehentner, Ján; Macháč, Jan; Mrkvica, Jan; Tuzi, Carlo
      (IEEE, 2003-10)
      The characteristics of modes on the conductor-backed slotline, the inverted conductor-backed slotline and on its modification in which the top dielectric layer with higher permittivity has a finite thickness, are presented ...
    • 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 ...
    • Upper Cut-Off Frequency of the Bound Wave and New Leaky Wave on the Slotline 

      Autor: Zehentner, Ján; Macháč, Jan; Migliozzi, Maurizio
      (IEEE, 1997-06)
      This paper contributes to a more profound understanding of uniplanar circuit behaviour. A simple closed-form formula providing the upper cut-off frequency of the bound wave propagating over the slotline is presented. A new ...
    • 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 ...
    • Visualization of leaky waves on planar transmission lines 

      Autor: Macháč, Jan; Zehentner, Ján; Mrkvica, Jan
      (IEEE, 2004-05)
      This paper presents a visualization of leaky waves excited by delta-gap sources on planar transmission lines, namely the 2nd surface and space leaky modes on the slotline, and the dominant and surface leaky modes on the ...
    • Waveguide bandpass filters with attenuation of higher-order passbands 

      Autor: Menzel, Wolfgang; Macháč, Jan
      (IEEE, 1993-09)
      A new method is proposed to provide additional attenuation to higher-order passbands of metal waveguide bandpass filters. To this end, shunt waveguide sections with cut-off frequencies are included into the filter structure. ...
    • Wide-Slotted Printed Slotline Radiator 

      Autor: Macháč, Jan; Zehentner, Ján; Lorenz, Petr; Mrkvica, Jan
      (IEEE, 2002)
      This paper summarizes the investigation of radiation from the slotline made on a thin low permittivity substrate. The slot radiates the space leaky wave of the first order. The dispersion characteristic of this wave is ...
    • Wideband VIP power divider with differential output 

      Autor: Sokol, V.; Hoffmann, K.; Škvor, Z.
      (IEEE, 2003-12)
      A novel wideband VIP power divider with out of phase outputs was designed and experimentally verified. The phase difference 180° ±5° and the amplitude difference ± 0.8 dB of output signals were achieved in 4-26 GHz frequency ...