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In some antennas the state of polarization will change with the frequency of transmission. The polarization of a commercial antenna is an essential specification. In the most general case, polarization is elliptical, meaning that over each cycle the electric field vector traces out an ellipse.
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 ...
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 ...
Antenna measurement techniques refers to the testing of antennas in order to ensure that the antenna meets specifications or simply to characterize it. Typical antenna parameters are gain , bandwidth , radiation pattern , beamwidth , polarization , impedance ; These are imperative communicative means.
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 ...
Polarization (physics), the ability of waves to oscillate in more than one direction; polarization of light allows the glare-reducing effect of polarized sunglasses Polarization (antenna) , the state of polarization (in the above sense) of electromagnetic waves transmitted by or received by a radio antenna