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Antenna Effective Aperture

October 8th Fact-of-the-Day

The effective aperture of an antenna is sometimes called its capture area. It is the frontal area from which a receiving antenna extracts energy from passing electromagnetic waves. The effective apertures of most antennas are larger than their physical sizes, which is the fundamental reason that two stacked antennas must be spaced some distance apart to double the amount of energy received. The ratio of the effective aperture to the physical aperture of an antenna is known as its K-factor. Yagi antennas have higher K-factors than most other designs. ©2004 Martek International All rights reserved.

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