Browsing by Author "Ho, K.-M."

Filter results by typing the first few letters
Now showing 1 - 3 of 3
  • Thumbnail Image
    ItemOpen Access
    Exceptionally directional sources with photonic-bandgap crystals
    (Optical Society of America, 2001-11) Biswas, R.; Özbay, Ekmel; Temelkuran, B.; Bayındır, Mehmet; Sigalas, M. M.; Ho, K.-M.
    Three-dimensional photonic-bandgap crystals are used to design and fabricate uniquely directional sources and receivers. By utilizing the resonances of a Fabry-Perot cavity formed with photonic-bandgap crystals, we were able to create exceptionally directional sources by placing the sources within such a cavity. Very good agreement between finite-difference time-domain calculations and the experiment is obtained. Radiation patterns with half-power beam widths of less than 12 degrees were obtained. (C) 2001 Optical Society of America.
  • Thumbnail Image
    ItemOpen Access
    Microwave applications of photonic band gap structures
    (IEEE, 2000-10) Temelkuran, Burak; Bayındır, Mehmet; Özbay, Ekmel; Biswas, R.; Sigalas, M. M.; Tuttle, G.; Ho, K.-M.
    We have investigated two major applications of photonic band gap materials. We demonstrated the guiding and bending of electromagnetic waves through planar waveguides built around layer-by-layer photonic crystals. We then investigated the radiation properties of an antenna that was formed by a hybrid combination of a monopole radiation source and a cavity built around the same photonic crystal structure. © 2000 IEEE.
  • Thumbnail Image
    ItemOpen Access
    Optimized dipole antennas on photonic band gap crystals
    (American Institute of Physics, 1995) Cheng, S. D.; Biswas, R.; Özbay, Ekmel; McCalmont, S.; Tuttle, G.; Ho, K.-M.
    Photonic band gap crystals have been used as a perfectly reflecting substrate for planar dipole antennas in the 12-15 GHz regime. The position, orientation, and driving frequency of the dipole antenna on the photonic band gap crystal surface, have been optimized for antenna performance and directionality. Virtually no radiated power is lost to the photonic crystal resulting in gains and radiation efficiencies larger than antennas on other conventional dielectric substrates.© 1995 American Institute of Physics.