Accession Number:

AD0269211

Title:

SOME CHARACTERISTICS OF HORIZONTAL DIPOLE ANTENNAS AT E. L. F

Descriptive Note:

Corporate Author:

DECO ELECTRONICS CAMBRIDGE MASS

Personal Author(s):

Report Date:

1961-12-12

Pagination or Media Count:

1.0

Abstract:

The performance of any antenna is dependent on the electrical properties of the earth beneath it. Unlike a vertical dipole, the horizontal dipole antenna operates best over a poor, low conductivity material. When positioned electrically close to a lossy material such as the earth which it must be at VLF and ELF, it is a very inefficient radiator. Nevertheless, its power radiating capability may easily be made to exceed that attainable from existing vertical dipoles VLF antennas at ELF. This is true basically because the vertical dipole is voltage limited while the horizontal dipole is current limited. Apparent conductivities were measured in 2 locations - Boulder, Colorado, and Pole Mountain District of the Medicine Bow National Forest, Wyoming. Antenna performances for arbitrary 10 mile long horizontal dipoles are calculated for each location at frequencies from 12 to 330 c. Vertical electric fields which would be produced at distances of 1,000, 4,000, and 10,000 km by a 1 megawatt transmitter with a 10 mile an tenna located in the Pole Mountain District are also given. The Precambrian granite in the Pole Mountain District was found to have an effective conductivity as seen by an incident electromagnetic wave of approximately 1100,000 mhosmeter. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE