Short VLF Antenna Study.
Abstract
An engineering analysis is performed to determine the new transmission efficiencies resulting from cooling the coupling and loading elements of an antenna operating in the frequency range 1 kHz to 30 kHz. The investigated area of application covers an electrically short, vertical monopole buried in a drill hole for deep rock strata hardened communications. Systems constraints include a 0.001 to 0.000001 mho per meter range in earth conductivity, a 10 to 100 mile communication range, a 0.000001 to 10 to the minus 9th power range in receiver sensitivity, and a 0.1 to 0.001 wavelength range in monopole length. Antenna types include bare monopoles, insulated monopoles, and terminated, insulated monopoles. A subsurface radiation resistance is defined and a subsurface range expression is generated to facilitate system performance calculations. Performance predictions are made for various types of monopoles in systems employing conventional, cryogenic, or superconducting coupling and loading techniques. Design criteria and data are presented; associated economic and technological factors are discussed. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1969
- Accession Number
- AD0847061
Entities
People
- Bernhard M. Schmidt
- George H. Kramer
- James D. Hoeffel