%0 Journal Article %T Hemispherical DRA Antennas Mounted on or Embedded in Circular Cylindrical Surface forProducing Omnidirectional Radiation Pattern %A Saber H. Zainud-Deen %A Noha A. El-Shalaby %A Kamal H. Awadalla %J Int'l J. of Communications, Network and System Sciences %P 601-608 %@ 1913-3723 %D 2011 %I Scientific Research Publishing %R 10.4236/ijcns.2011.49072 %X The radiation characteristics of hemispherical DRA elements mounted on or embedded in a hollow circular cylindrical ground structure are investigated. The performance of the DRA array which operates at about 1.8 Ghz, is studied. Factors influencing the array performance, such as the number of elements and element spacing are explained. The perforated dielectric technique is used to design the array from a single dielectric sheet. The overall profile of the antenna can be significantly reduced. The radiation patterns with respect to the number of DRA elements are depicted. %K DRAs %K FEM %K FIT %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=7227