ABSTRACT
An antenna is an essential component of any wireless communication system. Antennas are not as trendy as cameras or television sets, they do not have any attractive controls or colorful touch screens, but they are the most important part of the radio frequency broadcast system. Most broadcast antennas comprise many radiating elements creating an antenna array. These radiating elements can be slots in a pylon-style antenna or dipoles in a panel antenna. Antennas operate over a certain frequency range; usually the frequency range of operation is specified based on the Voltage standing wave ratio, but the limitation can also be due to intolerable pattern change. An omnidirectional antenna is supposed to radiate equally in all azimuth directions, but this is difficult to achieve on practical antennas. The antenna is elliptically polarized when the radiated electromagnetic wave has both vertically and horizontally polarized components. The traveling wave antenna can be built as coaxial type or a waveguide type.
