Insulated Subsurface Horizontal Wire Antennas at Shallow Depths; Dependence of Characteristic Parameters on Burial Depth.
Abstract
The characteristic parameters of near-the-earth horizontal wire antennas depend significantly on the height at which these antennas are suspended above ground. The question may be asked: Does a similar dependence on distance from the earth's surface exist for antennas buried at shallow depths. By using a transmission line approach, it is shown that variations of the input parameters are caused primarily by the height- or depth-dependence of the capacitance per-unit-length of the antenna wire. (In the case of a buried antenna, the wire is assumed to be insulated from the ground by a thick coat of a low-loss dielectric). The inductance and resistance per unit-length, on the other hand, are approximately constant in the range of low heights above ground to shallow burial depths. It is furthermore concluded that the capacitance per-unit-length of a subsurface antenna is also nearly constant as long as the antenna remains at a sufficient distance from the earth's surface. Hence, little variation of the input parameters should be expected in the range of small burial depths. The rather rapid variation of these parameters will commence only when the antenna is at such shallow depths that its capacitance per-unit-length is significantly affected by the presence of the air-earth interface. This variation continues as the antenna is thought to be raised out of the ground and into the air half-space. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1976
- Accession Number
- ADA027504
Entities
People
- F. Schwering
Organizations
- United States Army Communications-Electronics Command