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Dipole Radiated Field Intensity

December 19th Fact-of-the-Day

The maximum field intensity from a half-wave dipole radiating 1,000 watts is 138 mv per meter at a distance of 1 mile (1,610 Meters) in free space. However, the field intensity at 1 mile usually is different with a transmitting dipole located near earth, because the earth reflects part of the dipole radiation. The component of the radiation reflected from earth can have any phase relationship from 0 through 360 degrees with respect to the direct radiation, depending on the additional distance traveled. It can have any intensity from near-zero through near-unity with respect to the direct radiation, depending on the amount absorbed by earth. Consequently, the combined field intensity at 1 mile can range from near-zero to near-double the free-space 138 mv per meter intensity. ©2004 Martek International All rights reserved.


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