Technical
This type of antenna is called a Hogg or horn-reflector antenna, invented by Alfred C. Beck and Harald T. Friis in 1941. It was built by D. C. Hogg. It consists of a flaring metal horn with a reflector mounted in its mouth, at a 45° angle. The reflector is a segment of a parabolic reflector, so the antenna is really a parabolic antenna fed off-axis. A Hogg horn combines several characteristics useful for radio astronomy: it is extremely broad-band, has calculable aperture efficiency, and the walls of the horn shield it from radiation coming from angles outside the main beam axis, so back and sidelobes are so minimal that scarcely any thermal energy is picked up from the ground. Consequently it is an ideal radio telescope for accurate measurements of low levels of weak background radiation. The antenna has a gain of about 43.3 dBi and a beamwidth of about 1.5° at 2.39 GHz. and an aperture efficiency of 76%.
Read more about this topic: Holmdel Horn Antenna
Famous quotes containing the word technical:
“When you see something that is technically sweet, you go ahead and do it and you argue about what to do about it only after you have had your technical success. That is the way it was with the atomic bomb.”
—J. Robert Oppenheimer (1904–1967)
“Woman is the future of man. That means that the world which was once formed in man’s image will now be transformed to the image of woman. The more technical and mechanical, cold and metallic it becomes, the more it will need the kind of warmth that only the woman can give it. If we want to save the world, we must adapt to the woman, let ourselves be led by the woman, let ourselves be penetrated by the Ewigweiblich, the eternally feminine!”
—Milan Kundera (b. 1929)
“The axioms of physics translate the laws of ethics. Thus, “the whole is greater than its part;” “reaction is equal to action;” “the smallest weight may be made to lift the greatest, the difference of weight being compensated by time;” and many the like propositions, which have an ethical as well as physical sense. These propositions have a much more extensive and universal sense when applied to human life, than when confined to technical use.”
—Ralph Waldo Emerson (1803–1882)