| Definition: | a condition that occurs when the directivity of an antenna significantly exceeds that obtained from an aperture of the same dimension as that of the actual antenna but with uniform aperture illumination or, in the case of an array, from the array with elements uniformly excited
NOTE – Most frequently superdirectivity can be obtained only when amplitude and phase of currents, or field on the aperture, vary rapidly over distances short compared to the wavelength, which may lead to a very poor efficiency and usually renders the use of this property impractical.
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