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Horn Antennas Presentation

Horn Antennas Presentation

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Horn Antennas Presentation

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  1. Horn Antennas Presentation • Michelle Seale • Eric Day • Ryan Perry

  2. History • Invented in 1897 by J.C. Bose • A.B. Crawford Proved Big Bang Theory in 1959 • Accurate measurements of low levels of weak background radiation

  3. Horn Antenna • High Gain • 15 dBi – 17.5 dBi • Directionality • function of aperture • Impedance • flare matches waveguide to free space http://whatis.techtarget.com/definition/0,,sid9_gci214327,00.htmlWhatis

  4. Examples of Horn Antennas Pyramidal Conical

  5. Construction • Lc = λ Fcutoff = 2h • LO = λ open space • LG = λ in guide • (1/sqrt(1/Lo^2-1/Lc^2) http://users.skynet.be/chricat/horn/horn-javascript.html

  6. H & E Field Planes Direct H field & broad E field Direct E field & broad H field

  7. Radiation Pattern Electric Field Pattern http://web.mit.edu/mwpstr/www/foto/mwpspatr.htm http://www.ugastro.berkeley.edu/radiolab/antenna/horn_beampat.html

  8. Specifications http://www.tmeg.com/tutorials/antennas/antennas.htm

  9. 3 dB Beamwidth in Degrees 56 Aeλ: Aperture dimension in wavelengths in the Eplane Eplane = degrees Aeλ 67 Ahλ: Aperture dimension in wavelengths in the Hplane Hplane = degrees Ahλ Gain G ≈ 10 log10 (4.5*Aeλ*Ahλ) [dB over dipole] http://www.qsl.net/n1bwt/chap2.pdf

  10. Highway Patrol’s Radar Detectors • Microwave Communications • Feeds for Reflector Antennas • Arrays of Horn Antennas can be used to closely control Radiation Patterns. • WiFi 802.11b Applications http://whatis.techtarget.com/definition/0,,sid9_gci214327,00.htm “Microwave Horns and Feeds,” by Olver, Clarricoats, Kishk, and Shafail