Accession Number:

AD0766703

Title:

Low-Profile VHF Antennas for Seismic Detection Systems.

Descriptive Note:

Technical rept.,

Corporate Author:

HARRY DIAMOND LABS WASHINGTON D C

Personal Author(s):

Report Date:

1973-06-01

Pagination or Media Count:

49.0

Abstract:

The paper describes the design, fabrication, and evaluation of three different types of low-profile VHF antennas and their applications with seismic detection systems at or near ground level. These electrically small antennas vertically polarized include a capacitively tuned multi-turn loop over a small metal ground plane, a spiral transmission line top-loaded monopole, and a capacitor-plate antenna that can be inductively tuned over a wide frequency range. The radiation pattern of each is essentially that of a dipole, omnidirectional in the horizontal plane and represented by a solid of revolution generated by a rotating figure of 8. All of the above elemental dipole antennas were designed for optimum performance in the 100- to 200MHz frequency range, compatible with various physical, electrical, and environmental constraints determined by the terminal delivery vehicle TDV of the seismic detector system. Distinctive features of these low-profile antennas include small size 3 in. maximum, simplicity of construction, and low fabrication costs. Author

Subject Categories:

  • Electrical and Electronic Equipment
  • Seismic Detection and Detectors

Distribution Statement:

APPROVED FOR PUBLIC RELEASE