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Circular polarization is a limiting case of elliptical polarization. The other special case is the easier-to-understand linear polarization . All three terms were coined by Augustin-Jean Fresnel , in a memoir read to the French Academy of Sciences on 9 December 1822.
This antenna is unusual in that it radiates in all directions (no nulls in the radiation or reception pattern), with horizontal polarization in directions coplanar with the elements, circular polarization normal to that plane, and elliptical polarization in other directions. Used for receiving signals from satellites, as circular polarization ...
A turnstile antenna, or crossed-dipole antenna, [1] is a radio antenna consisting of a set of two identical dipole antennas mounted at right angles to each other and fed in phase quadrature; the two currents applied to the dipoles are 90° out of phase. [2] [3] The name reflects the notion the antenna looks like a turnstile when mounted ...
Note that for circular polarization, optical researchers use the opposite right-hand rule [citation needed] from the one used by radio engineers. It is best for the receiving antenna to match the polarization of the transmitted wave for optimum reception.
The receiving feed antenna must also have vertical polarization to receive them; if the feed is horizontal (horizontal polarization) the antenna will suffer a severe loss of gain. To increase the data rate, some parabolic antennas transmit two separate radio channels on the same frequency with orthogonal polarizations, using separate feed ...
A Vivaldi antenna or Vivaldi aerial [1] or tapered slot antenna [2] is a co-planar broadband-antenna, which can be made from a solid piece of sheet metal, a printed circuit board, or from a dielectric plate metalized on one or both sides. Patterned Vivaldi antenna, made from double-sided printed circuit board material
A helical antenna is an antenna consisting of one or more conducting wires wound in the form of a helix.A helical antenna made of one helical wire, the most common type, is called monofilar, while antennas with two or four wires in a helix are called bifilar, or quadrifilar, respectively.
Unlike a dipole antenna, the polarization of a resonant loop antenna is not obvious from the orientation of the loop itself, but depends on the placement of its feedpoint. [e] If a vertically oriented loop is fed at the bottom, then its radiation will be horizontally polarized; feeding it from the side will make it vertically polarized.