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An antenna's polarization can sometimes be inferred directly from its geometry. When the antenna's conductors viewed from a reference location appear along one line, then the antenna's polarization will be linear in that very direction. In the more general case, the antenna's polarization must be determined through analysis.
For a linearly-polarized antenna, this is the plane containing the electric field vector (sometimes called the E aperture) and the direction of maximum radiation. The electric field or "E" plane determines the polarization or orientation of the radio wave. For a vertically polarized antenna, the E-plane usually coincides with the vertical ...
The first modern horn antenna in 1938 with inventor Wilmer L. Barrow. A horn antenna or microwave horn is an antenna that consists of a flaring metal waveguide shaped like a horn to direct radio waves in a beam. Horns are widely used as antennas at UHF and microwave frequencies, above 300 MHz. [1]
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.
Turnstile antennas can be stacked and fed in phase to realize an omnidirectional broadside array or phased for an end-fire array with circular polarization. The batwing antenna is a turnstile antenna with its linear elements widened as in a bow-tie antenna, again for the purpose of widening its resonant frequency and thus usable over a larger ...
Polarization diversity combines pairs of antennas with orthogonal polarizations (i.e. horizontal/vertical, ± slant 45°, Left-hand/Right-hand circular polarization etc.). Reflected signals can undergo polarization changes depending on the medium through which they are traveling.
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
In a transmitting antenna, XPD is the fraction of power from an antenna of one polarization radiated in the other polarization. For example, due to minor imperfections a dish with a vertically polarized feed antenna will radiate a small amount of its power in horizontal polarization; this fraction is the XPD.