ELF, VLF and LF radiation from a very large loop antenna with a mountain core

Author

Barr, R. ; Ireland, W. ; Smith, M.J.

Author_Institution

Nat. Inst. of Water & Atmos. Res., Lower Hutt, New Zealand

Volume

140

Issue

2

fYear

1993

fDate

4/1/1993 12:00:00 AM

Firstpage

129

Lastpage

134

Abstract

The establishment of an LF/VLF/ELF transmitting facility at the Homer tunnel near Milford South in the South Island of New Zealand is described. The antenna consisted of a 3.3 km-long PVC-covered aluminium conductor passing through the tunnel and over the mountain above, forming a large vertical loop antenna. Measurements of the electric field radiated from the transmitter, recorded at both Lauder and Palmerston, 133 and 225 km from the transmitter site, respectively, are presented. The antenna radiation pattern derived from observations made onboard an Orion aircraft circling the antenna at a distance of 200 km is also presented. Theoretical models are derived which enable fits to the radiated field data to be made over a wide frequency range (0.5-40 kHz). With 1 kW of input power the antenna produced peak radiated fields at frequencies near 10 kHz equivalent to those of a vertical monopole source radiating 150 mW

Keywords

antenna radiation patterns; field strength measurement; loop antennas; 0.5 to 40 kHz; 133 km; 200 km; 225 km; 3.3 km; ELF; Homer tunnel; LF; New Zealand; PVC-covered aluminium conductor; VLF; antenna radiation pattern; electric field; field strength; mountain core; peak radiated fields; vertical loop antenna; very large loop antenna;

fLanguage

English

Journal_Title

Microwaves, Antennas and Propagation, IEE Proceedings H

Publisher

iet

ISSN

0950-107X

Type

jour

Filename

212602