Paraboolantenne: Verskil tussen weergawes
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Om die straalwydte so klein as moontlik te maak moet die paraboliese weerkaatser baie groter as die [[golflengte]] van die radiogolwe wees,<ref name="Stutzman" /> daarom word paraboolantennes eerder in die hoër frekwensie gedeelte van die radiospektrum gebruik: Ultrahoë frekwensie en [[mikrogolf]] super hoë frekwensies, waar die golflengte klein genoeg is sodat paraboliese weerkaatsers met gemak gebruik kan word.
Paraboolantennes word gebruik as hoë-wins antennes vir punt-na-punt kommunikasie in toepassings soos mikrgolf roetes wat telefonie en televisie seine tussen stede dra, draadlose WAN/LAN skakels vir data kommunikasie, satellietkommunikasie en soos gebruik deur ruimtetuie. Dit word ook gebruik in [[Radioteleskoop|radioteleskope]].
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The other large use of parabolic antennas is for [[radar]] antennas, in which there is a need to transmit a narrow beam of radio waves to locate objects like ships, [[airplane]]s, and [[guided missile]]s, and often for weather detection.<ref name="Stutzman" /> With the advent of [[direct broadcast satellite|home satellite television]] receivers, parabolic antennas have become a common feature of the landscapes of modern countries.<ref name="Stutzman" />
The parabolic antenna was invented by German physicist [[Heinrich Hertz]] during his discovery of radio waves in 1887. He used cylindrical parabolic reflectors with spark-excited dipole antennas at their focus for both transmitting and receiving during his historic experiments.
[[Image:Parabola with focus and arbitrary line.svg|thumb|upright=1.3|Parabolic antennas are based on the geometrical property of the paraboloid that the paths ''FP<sub>1</sub>Q<sub>1</sub>, FP<sub>2</sub>Q<sub>2</sub>, FP<sub>3</sub>Q<sub>3</sub>'' are all the same length. So a spherical wavefront emitted by a feed antenna at the dish's focus ''F'' will be reflected into an outgoing plane wave ''L'' travelling parallel to the dish's axis ''VF''.]]
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