Advanced Search
Select up to three search categories and corresponding keywords using the fields to the right. Refer to the Help section for more detailed instructions.

Search our Collections & Repository

All these words:

For very narrow results

This exact word or phrase:

When looking for a specific result

Any of these words:

Best used for discovery & interchangable words

None of these words:

Recommended to be used in conjunction with other fields

Language:

Dates

Publication Date Range:

to

Document Data

Title:

Document Type:

Library

Collection:

Series:

People

Author:

Help
Clear All

Query Builder

Query box

Help
Clear All

For additional assistance using the Custom Query please check out our Help Page

i

Admittance and effective height of buried antennas

Filetype[PDF-27.45 KB]


  • English

  • Details:

    • Personal Author:
    • Description:
      Explicit expressions are presented for the input admittance and effective height of several buried metal antennas, namely: (i) prolate spheroidal; (ii) spherical; (iii) oblate spheroidal; (iv) parallel plate; (v) parallel plate with protruding dielectric in the same plane of the plates; (vi) parallel plate with protruding dielectric in a plane normal to that of the plates (H-shaped antenna). Explicit expressions are presented for the input admittance and effective height of several buried metal antennas, namely: (i) prolate spheroidal; (ii) spherical; (iii) oblate spheroidal; (iv) parallel plate; (v) parallel plate with protruding dielectric in the same plane of the plates; (vi) parallel plate with protruding dielectric in a plane normal to that of the plates (H-shaped antenna). It is concluded that in all practical situations of "small" antennas approximation 1 is almost always appropriate. Computations were carried out for bare antennas, the extension to insulated ones being, however, straightforward. Although a rigorous theory of the antenna performance in a realistic semi-infinite conductive medium has not been developed, the results quoted should also be applicable when antennas are a few skin depths below the earth's surface. In particular, for the evaluation of radio-links under up-over -and-down operating conditions, the antennas can be replaced by dipoles of length equal to the effective height. Since the antenna's parameters are given in analytical form, it is also possible, by using Laplace transform techniques, to compute the transient response of the antenna. The transient is described by pole (short-time behavior) and branch-cut contributions (large time behavior). For these last terms, an asymptotic evaluation is possible, so obtaining closed form expressions for the response at large observation times, which is closely related to the dispersion characteristic of the environment.
    • Document Type:
    • Main Document Checksum:
    • File Type:

    Supporting Files

    • No Additional Files

    More +

    Related Documents

    You May Also Like

    Checkout today's featured content at stacks.cdc.gov