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The top shows the directive pattern of a horn antenna, the bottom shows the omnidirectional pattern of a simple vertical dipole antenna. In the field of antenna design the term radiation pattern (or antenna pattern or far-field pattern) refers to the directional (angular) dependence of the strength of the radio waves from the antenna or other ...
Antenna directivity is the ratio of maximum radiation intensity (power per unit surface) radiated by the antenna in the maximum direction divided by the intensity radiated by a hypothetical isotropic antenna radiating the same total power as that antenna. For example, a hypothetical antenna which had a radiated pattern of a hemisphere (1/2 ...
This is extremely useful when the antenna is at a very high point, and the edge of the signal is likely to miss the target (broadcast audience, cellphone users, etc.) entirely. With electrical tilting, front and back lobes tilt in the same direction. For example, an electrical downtilt will make both the front lobe and the back lobe tilt down.
A beam waveguide antenna is a type of complicated Cassegrain antenna with a long radio wave path to allow the feed electronics to be located at ground level. It is used in very large steerable radio telescopes and satellite ground antennas, where the feed electronics are too complicated and bulky, or requires too much maintenance and alterations, to locate on the dish; for example those using ...
Many antenna types, such as reflective array antennas, use flat surfaces of metal or metal screen to reflect radio waves from the antenna elements, and these can be analyzed using image antennas. If there is more than one reflective surface in the antenna, as in a corner reflector antenna, each surface forms its own image of the antenna elements.
Typical GSM sector antenna outdoor unit. A sector antenna is a type of directional microwave antenna with a sector-shaped radiation pattern.The word "sector" is used in the geometric sense; some portion of the circumference of a circle measured in degrees of arc. 60°, 90° and 120° designs are typical, often with a few degrees 'extra' to ensure overlap and mounted in multiples when wider or ...
The interferometric visibility (also known as interference visibility and fringe visibility, or just visibility when in context) is a measure of the contrast of interference in any system subject to wave superposition. Examples include as optics, quantum mechanics, water waves, sound waves, or electrical
Forms of the reciprocity theorems are used in many electromagnetic applications, such as analyzing electrical networks and antenna systems. [1] For example, reciprocity implies that antennas work equally well as transmitters or receivers, and specifically that an antenna's radiation and receiving patterns are identical.