Prohlížení Fakulta elektrotechnická dle autora "Macháč, Jan"
-
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 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 ... -
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 ... -
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 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 ...