Abstract: A scheme is proposed that it permits a more direct prediction of the radiation pattern of a parabolic reflector antenna from an experimental plot of the electric field strength over the focal region of a larger parabolic reflector in the near field of the test antenna. For any off-axis angle, only one gain value may be defined.
Computing Antenna Patterns Figure 3.12: Aperture illumination for a parabolic dish. I think it will be helpful for those who are interested in studying the effect of these parameters on the radiation pattern shape of the parabolic reflector antenna. Parabolic Antenna. Degradations include beam-shape distortion, gain, loss, beamwidth, and higher side lobes. Figure 2. The HPBW is approximately 5 degrees, and the front-to-back ratio is approximately 33 dB. The antenna pattern must give the antenna gain as a function of the off-axis angle. Reflector antennas are not good for continuous beam scanning, as beam degradation does occur. Parabolic antenna calculator example: INPUTS: Frequency = 14.5 GHz, Diameter = 3.5 meter OUTPUTS: Gain = 52.3 dB, Beamwidth= 0.35 degrees, Aperture= 5.77 meter 2 Parabolic Antenna calculator equation. Degradations include beam-shape distortion, gain, loss, beamwidth, and higher side lobes. Consider a parabolic reflecting telescope being fed by a feed at the focus.
Isotropic Pattern - an antenna pattern defined by uniform radiation in all directions, produced by an isotropic radiator (point source, a non-physical antenna which is the only nondirectional antenna). These reflectors are used in TV antennas and satellite communications, for example. The antenna pattern is usually a graphical representation of the antenna's directional characteristic.
Examples of this dish antenna are shown in the following Figures. Figure 1.
The antenna gain must be defined for all off-axis angles between 0 and 180 degrees.
Directional Pattern - a pattern characterized by more efficient radiation in one direction than another (all physically realizable antennas are directional antennas). These reflectors are used in TV antennas and satellite communications, for example. Physical attributes of an antenna, in conjunction with the operating frequency, results in constructive and destructive interference patterns being set up a points distant from the antenna. Video Overview of Parabolic Reflector Antennas.
Parabolic antenna calculator example: INPUTS: Frequency = 14.5 GHz, Diameter = 3.5 meter OUTPUTS: Gain = 52.3 dB, Beamwidth= 0.35 degrees, Aperture= 5.77 meter 2 Parabolic Antenna calculator equation Parabolic dish is widely used as satellite TV channel receiver across the world. If you prefer to listen to an intro on parabolic reflector antennas, here is a video discussing some of the major points: