HORIZONTAL VLF TRANSMITTING ANTENNAS NEAR THE EARTH
Abstract
Problems encountered in VLF radiation are outlined and variations of the horizontal dipole are proposed as a solution. Equations are derived for the radiation patterns, input impedance, and efficiency of the broad-band antenna (terminated in its characteristic impedance) and of the narrow-band antenna (open-terminated) where the antenna is fed at any position along its length. Data are presented to substantiate that (1) the horizontal dipole near the earth exhibits super gain when several parallel conductors are used; (2) the radiation efficiency of 'n' closely spaced conductors is 'n' times greater than when the same conductors are spaced one-half wavelength apart; and (3) the lossy horizontal dipole normally does not resonate when its length is a multiple of one-half wavelength. The 'lossy lengthening factor' is shown in a plot of the resonant length as a function of 'Q'. This plot applies generally to all lossy dipoles.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 15, 1967
- Accession Number
- AD0653851
Entities
People
- Elwin W. Seeley
- Philip H. Wiborg
Organizations
- Naval Ordnance Laboratory