The introduction of broadband systems to communication and radar technologies has demanded the design of broadband antennas. In this thesis, broadband log-periodic dipole antennas and reflector antennas are investigated. A dual polarized log-periodic dipole antenna and a reflector antenna are designed and analyzed within the frequency band of 0.4-18 GHz.
Basic theory and calculations about mutual coupling between the linear antenna elements are given. The currents at the bases of dipoles of the log-periodic antenna are found and these currents are used as inputs for the design of the reflector antenna. After the simulations made with MATLABÒ / and FORTRAN, a prototype single polarized log-periodic antenna is produced. Developments on the prototype antenna are performed, both to improve the electrical characteristics of the antenna and to make the final design realizable. After the performance of the single polarized log-periodic antenna is found satisfactory, dual polarized antenna is produced.
Performances of both single and dual polarized log-periodic antennas are measured in the anechoic chamber at ASELSAN® / Inc. After the measurements of the antenna, using the currents at the bases of the dipoles, a reflector antenna is designed using &ldquo / MIR&rdquo / program written in FORTRAN, which is based on physical optics method. A method to calculate the aperture blockage of the reflector is developed. Simulation results of reflector antenna are given.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12605948/index.pdf |
| Date | 01 June 2005 |
| Creators | Tanyer, Fatma Muge |
| Contributors | Hizal, Altunkan |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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