• About
  • Policies
  • What is open access
  • Library
  • Contact
Advanced search
      View Item 
      •   BUIR Home
      • University Library
      • Bilkent Theses
      • Theses - Department of Electrical and Electronics Engineering
      • Dept. of Electrical and Electronics Engineering - Master's degree
      • View Item
      •   BUIR Home
      • University Library
      • Bilkent Theses
      • Theses - Department of Electrical and Electronics Engineering
      • Dept. of Electrical and Electronics Engineering - Master's degree
      • View Item
      JavaScript is disabled for your browser. Some features of this site may not work without it.

      Analysis and design of broadcast tower antenna systems

      Thumbnail
      View / Download
      12.9 Mb
      Author(s)
      Ali Abdul
      Advisor
      Altıntaş, Ayhan
      Date
      2014
      Publisher
      Bilkent University
      Language
      English
      Type
      Thesis
      Item Usage Stats
      298
      views
      987
      downloads
      Abstract
      In broadcasting, the coverage and interference requirements of antennas are designated in terms of Effective Radiated Power (ERP), tower location and height, and antenna patterns. When antennas are tailored to satisfy the requirements, transmitter powers, cable losses, and phase adjustments for antenna elements must be taken into account in addition to the parasitic effect of the supporting and nearby towers on characteristics of antenna. Digital video and audio broadcasting requires antennas to be at least 95 % effi- cient, wideband, low weight and high gain with enhanced radiation performance. For this reason many wire and planar antennas have been designed to meet the requirement of Digital Video Broadcasting-Terrestrial (DVB-T) and TerrestrialDigital Audio Broadcasting (T-DAB). We used a tool NEC (Numerical Electromagnetic Code) to model antenna on top of a tower structure. Simulation results for parasitic effect of the tower on characteristics of antenna such as impedance, return loss, gain, front-to-back ratio and radiation patterns are reported. In addition, the effect of nearby tower on antenna characteristics is studied. We designed a broadband antenna in the UHF (470 - 860 MHz) band that works for both digital and analog TV with return loss ≥10 dB, fractional bandwidth of 85% and gain at center frequency 12.5 dB. The ERP is calculated by mounting the antenna at each face of the tower to give a satisfactory coverage to a region around the antenna. Moreover, the design of a transmitter antenna for DVB-T and T-DAB is presented with Stacked Suspended Plate Antenna (SSPA) structure. Considering the similar products in the world, antennas have been designed in (174-254)MHz for DVB-T and (174-230)MHz for T-DAB with horizontal polarization and return loss ≥ 10 dB. The antenna gives an average gain of 8.5 dB and cross polarization isolation is 31 dB. Contrary to conventional dipole structures, we have employed SSPA structure with two plates for wideband matching and design flexibility. Radiating primary plate has been excited by novel wideband modified inverted L-type probe in a capacitively coupled manner. Vertical plate between primary plate and ground plane also provides wideband matching and adjustment of halfpower beam width properly. Parasitic secondary plate has been used for further matching and tuning. Together with the parametric study of designed antenna, simulation and measurement results for the input impedance, S11, gain and radiation patterns are presented.
      Keywords
      DVB-T
      T-DAB
      SSPA
      Broadcasting Antennas
      Permalink
      http://hdl.handle.net/11693/18319
      Collections
      • Dept. of Electrical and Electronics Engineering - Master's degree 655
      Show full item record

      Browse

      All of BUIRCommunities & CollectionsTitlesAuthorsAdvisorsBy Issue DateKeywordsTypeDepartmentsCoursesThis CollectionTitlesAuthorsAdvisorsBy Issue DateKeywordsTypeDepartmentsCourses

      My Account

      Login

      Statistics

      View Usage StatisticsView Google Analytics Statistics

      Bilkent University

      If you have trouble accessing this page and need to request an alternate format, contact the site administrator. Phone: (312) 290 2976
      © Bilkent University - Library IT

      Contact Us | Send Feedback | Off-Campus Access | Admin | Privacy