Now showing items 1-12 of 12

  • Compact Size UWB Monopole Antenna with Triple Band-Notches 

    Ali, W.; Ibrahim, A. A.; Machac, J. (Společnost pro radioelektronické inženýrství, 2017-04)
    This paper presents triple band notched ultra wide band (UWB) monopole antenna with overall size of 36 × 32 mm2 fed by microstrip transmission line. In order to achieve a good impedance matching from 2.7 GHz to 13.4 GHz, ...
  • Improvement of Reading Performance of Frequency-Domain Chipless RFID Transponders 

    Havlicek, J.; Svanda, M.; Machac, J.; Polivka, M. (Společnost pro radioelektronické inženýrství, 2016-06)
    This review paper presents the summary of our investigations in several topics of frequency-domain chipless RFID transponders. The performance comparison of various types of scatterers used in the literature and recently ...
  • Isotropic Single Negative Metamaterials 

    Machac, J.; Protiva, P.; Rytir, M.; Blaha, M.; Zehentner, J. (Společnost pro radioelektronické inženýrství, 2008-09)
    This paper presents the application of simple, and therefore cheap, planar resonators for building 3D isotropic metamaterials. These resonators are: a broadside-coupled split ring resonator with a magnetic response providing ...
  • Low-profile Slotted SIW Cavity Backed Antenna for Frequency Agility, 

    Sboui, F.; Machac, J.; Gharsallah, A. (Společnost pro radioelektronické inženýrství, 2019-06)
    The agile frequency antennas are widely used for wireless communication systems. This paper studies and designs a low-profile SIW antenna radiating from a circular slot graved in the ground plane, with the ability of ...
  • New Planar and Volume Versions of a Metamaterial 

    Machac, J.; Hudlicka, M.; Buchar, P.; Zehentner, J. (Společnost pro radioelektronické inženýrství, 2005-12)
    Some characteristics of materials with negative permittivity and permeability, i.e., with a negative refrative index, known as metamaterials, are presented in this paper. Dispersion characteristics of left-handed parallel ...
  • A New Version of the Microstrip to Waveguide Transition 

    Machac, J. (Společnost pro radioelektronické inženýrství, 1992-10)
    A new version of the microstrip-to-waveguide transition is described and analyzed. It is the E-plane transition, where the stripe probe is substituted by a rectangular patch. The structure is very simple, easily adjustable, ...
  • Planar Hexagonal Antenna with Dual Reconfigurable Notched Bands for Wireless Communication Devices 

    Ayadi, H.; Machac, J.; Beldi, S.; Latrach, L. (Společnost pro radioelektronické inženýrství, 2021-04)
    In this paper, a planar hexagonal antenna with dual tunable notched band using varactor diodes is presented. The designed antenna operates in the frequency range of 2 GHz to 8 GHz and is loaded by a complementary split ...
  • Planar Resonators for Metamaterials 

    Blaha, M.; Machac, J. (Společnost pro radioelektronické inženýrství, 2012-09)
    This paper presents the results of an investigation into a combination of electric and magnetic planar resonators in order to design the building element of a volumetric metamaterial showing simultaneously negative electric ...
  • Space Leaky Waves Propagating along a Pair of CRLH SIW Lines 

    Noumi, R.; Machac, J.; Gharsallah, A. (Společnost pro radioelektronické inženýrství, 2018-09)
    A space leaky wave excited on composite right-left handed substrate integrated waveguide radiates in a wide frequency band is presented in this paper. The proposed two line array is a good candidate for smart systems of ...
  • Universal Generator of Ultra-Wideband Pulses 

    Protiva, P.; Mrkvica, J.; Machac, J. (Společnost pro radioelektronické inženýrství, 2008-12)
    An Ultra-Wideband (UWB) subnanosecond pulse generator is described in this paper. High amplitude Gaussian pulses are generated by a Step Recovery Diode (SRD) included in a novel pulse forming circuit. The pro-posed circuit ...
  • UWB Monopole Antenna with Band Notched Characteristics Mitigating Interference with WiMAX 

    Ibrahim, A. A.; Ali, W.; Machac, J. (Společnost pro radioelektronické inženýrství, 2017-06)
    Compact asymmetric coplanar strip (ACS) - fed monopole antenna is presented in this paper for operation in ultra wide-band (UWB) applications. The antenna is composed of a semi-elliptical monopole and lateral coplanar ...
  • Waveguide Filters Supressing Higher-Order Passbands 

    Machac, J.; Menzel, W. (Společnost pro radioelektronické inženýrství, 1994-07)
    A new class of waveguide bandpass filters with suppressed higher-order passbands is described, designed, theoretically and experimentally verified. Methods of minimal autonomous blocks and mode matching are used for analysis. ...