Band-stop parabolic reflector design and electrical tests

Keywords: Frequency Selective Surfaces, Elektromagnetik Filters, Parabolic Reflectors, Antennas Nowadays, the frequency bandwidth increased from a few hundred kilo hertz to a few giga hertz by the improvement of wireless communication systems. As it is known, the most basic elements of wireless communication systems are the receiver antenna that collects the electromagnetic waves emitted in the space and converts them into electrical current and the transmitter antenna that converts the electrical current into electromagnetic waves and spreads into the space. Size and structural feature of the antennas which are used in communication systems changes up to the value of operating frequency. In the literature, it can be seen that different structural featured antennas such as; monopole, dipole, micro-stripe, slot, horn and parabolic reflector are existing. In the proposed study, in order to used in civil and military communication systems, it is aimed to design, numerical analysis and prototype production of a parabolic reflector which has a band stop filter characteristic. For this purpose, firstly theoretical information about antennas are given in this thesis, then, frequency selective surfaces such as, band-stop, band-pass, low-pass and high-pass filter characteristics are studied. Existing studies show that frequency selective surfaces (FSSs) have two dimensional structure and located on the printed circuit board. In this thesis, in order to improve the physical performance as well as its electrical characteristics, a novel parabolic FSS model obtained by periodically positioning of finite length conductive fibers with circular cross-section into the host material is proposed. Computer Simulation Technology (CST) is used to obtain the parameter values of the proposed model for desired operating frequency values. At the end of thesis, parabolic FSS is produced and nümerical results are validated by measurements.