annular antenna

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• Metamaterial antenna — This Z antenna tested at the National Institute of Standards and Technology is smaller than a standard antenna with comparable properties. Its high efficiency is derived from the Z element inside the square that acts as a metamaterial, greatly… …   Wikipedia

• Short backfire antenna — A short backfire antenna (or short back fire, SBA, SBF or SBFA) is a type of a directional antenna, characterized by high gain, relatively small size, and narrow band. It has a shape of a disc with a straight edge, with a vertical pillar with a… …   Wikipedia

• Onychophora — Temporal range: 40–0 Ma …   Wikipedia

• Velvet worm — Taxobox name = Onychophora fossil range = Cambrian – Recent image width = 250px image caption = Velvet worm regnum = Animalia phylum = Onychophora phylum authority = Grube, 1853 subdivision ranks = Extant families subdivision = Peripatidae… …   Wikipedia

• beam width — The full angular interval in the horizontal plane between the points at which the power radiated from the antenna has fallen to half its maximum value. In practice, the effective beam width may be less than this value and may be altered by use of …   Aviation dictionary

• History of astronomical interferometry — See also: astronomical interferometerWilliam Herschel knew as early as 1779 (Herschel 1805) that stars appeared much larger in telescopes than they really were but he did not know why. When Thomas Young demonstrated interference and the wave… …   Wikipedia

• Glossary of Lepidopteran terms — Tornus redirects here. For the gastropod genus, see Tornus (gastropod).This glossary describes the terms used in the formal descriptions of lepidopteran species. Like all insects, adult butterflies have three distinctive segments to their bodies …   Wikipedia

• Sulfur lamp — The sulfur lamp (also sulphur lamp) is a highly efficient full spectrum electrodeless lighting system whose light is generated by sulfur plasma that has been excited by microwave radiation. The technology was developed in the early 1990s, but,… …   Wikipedia

• DXing — is the hobby of tuning in and identifying distant radio or television signals, or making two way radio contact with distant stations in amateur radio, citizens band radio or other two way radio communications. Many DXers also attempt to receive… …   Wikipedia

• antennaria — n. [L. antenna, feeler] (ARTHROPODA: Insecta) In immatures, an annular sclerite forming the periphery of each antennal sclerite …   Dictionary of invertebrate zoology

• antennula — The first paired cephalic appendage. In munnopsids, it consists of a wide, flattened basal segment, two segments of intermediate thickness, and distal annular segments of varying lengths. The most distal segments generally bear aesthetascs. (Syn …   Crustacea glossary