Browsing by Subject "End-fire"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    Decoupling of multifrequency dipole antenna arrays for microwave imaging applications
    (Hindawi Publishing Corporation, 2010) Saenz, E.; Guven, K.; Özbay, Ekmel; Ederra, I.; Gonzalo, R.
    The mutual coupling between elements of a multifrequency dipole antenna array is experimentally investigated by S -parameter measurements and planar near-field scanning of the radiated field. A multifrequency array with six dipoles is analyzed. In order to reduce the coupling between dipoles, a planar metasurface is placed atop the array acting as superstrate. The mutual coupling of the antenna elements in the absence and presence of the superstrate is presented comparatively. Between 3 and 20dB mutual coupling reduction is achieved when the superstrate is used. By scanning the field radiated by the antennas and far-field measurements of the radiation pattern, it is observed that the superstrate confines the radiated power, increases the boresight radiation, and reduces the endfire radiation.
  • Thumbnail Image
    ItemOpen Access
    Quantum entanglement via superradiance of a Bose-Einstein condensate
    (Institute of Physics Publishing, 2010) Taşgın, M. E.; Oktel, M. Ö.; You, L.; Müstecaploǧlu, Ö. E.
    We adopt the coherence and built-in swap mechanism in sequential superradiance as a tool for obtaining continuous-variable (electric/magnetic fields) quantum entanglement of two counter-propagating pulses emitted from the two end-fire modes. In the first-sequence, end-fire modes are entangled with the side modes. In the second sequence, this entanglement is swapped to in between the two opposite end-fire modes. Additionally, we also examine the photon number correlations. No quantum correlations is observed in this variable.