The aim of this report is to research wireless antennas and differences between them. Antennas are included 3 types: omnidirectional, semi-directional, and highly-directional. Any antenna has three fundamental properties: gain, directional and polarization. Omnidirectional Antennas.
We can use this antenna in a: point-multipoint link, warehouse, hotspot, trade show, airport. The omnidirectional antennas transmit a signal in all directions, it is known dipole ("non-directional") antenna. The most of common antenna with low gain are "Rubber Ducky", vertically oriented dipole antenna, ground plane antenna, discone antenna etc. Dipole antennas omnidirectional antenna is used 2.14 dBi. For more efficiency of antenna is best if length of the fraction will be ¼ or ½ or multiple of the wavelength (λ). The half-wave dipole antenna is 2.4 GHz and 5 GHz. If the antenna is shorter the wavelength is higher. The gain rating antenna is measured in a dBi. Our antenna must be a higher dBi to cover more areas. If the antenna has 14 dBi it can cover distances approximately half a mile. In the High gain antenna beams less energy and lower elevation and more a horizontal. The collinear dipole arrays are used by High gain. It is used outdoors for linking varied buildings together. It is designed for a hotspot to use in a large area. If we imagine signal of omnidirectional antenna is circular because antenna in most of cases mounts in a perpendicular plane. Access point in most of cases is used omnidirectional antenna. The range of vertical beam width is approximately 45 -1800 and it has narrow coverage. The radio frequency of horizontal beam width in the omnidirectional antenna is 3600 . In most of cases omnidirectional antenna is used in wireless computer networks, radio broadcasting, FM radio, cell phone etc. Semi - directional antenna.
It is transmitting signals in more one direction as opposed to an omnidirectional antenna. When the signal of the...
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