aperture

aperture: 1. In a directional antenna, the portion of a plane surface very near the antenna normal to the direction of maximum radiant intensity, through which the major part of the radiation passes. (188) 2. In an acoustic device that launches a sound wave, the passageway, determined by the size of a hole in the inelastic material and the wavelength. [After 2196]

This HTML version of FS-1037C was last generated on Fri Aug 23 00:22:38 MDT 1996