ELF Communications Antennas - IEEE Xplore

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by a multiplication sign. In eqn. 4, the final exponential should be. IEE Electromagnetic Waves Series 5. ELF Communications Antennas. The ELF band (30 to ...
10 HALFORD, D., SHOAF, J. H., and RISLEY, A. S.: 'Frequency domain specification and measurement of signal stability'. Proceedings of the 27th annual frequency control symposium, Cherry Hill, New Jersey, USA, June 1973, pp. 421-431 (National Technical Information Service Accession no. AD771O42) 11 HOWE, D. A.: 'Frequency domain stability measurements: a tutorial introduction'. NBS Technical Note 679, 1976 (US Department of Commerce, National Bureau of Standards, Boulder, Co. 80302, USA)

12 BLANEY, T. G., CROSS, N. R., and KNIGHT, D. J. E.: 'Harmonic mixing and frequency measurement at 2-5 THz using Josephson junctions',/. Phys. D, 1976, 9,pp. 2175-2180 13 BUSH, D. L.- 'Single-loop phase-locked mm klystrons and IMPATT oscillators', Microwave J., November 1974, pp. 49-51 14 BAPRAWSKI, J., SMITH, G., and BERNUES, F. J.: 'Phase locked solid state mm-wave sources', ibid., October 1976, pp. 41-44

0013-5194/78/1163-0451 $1.50/0

ERRATA LOVE, J. D., and WINKLER, C: 'Goos-Hanchen shift for leaky rays on step-index waveguides', Electron. Lett., 1978, 14, pp. 379-381

HARRIS, A. B.: 'Contribution of reflector profile errors to antenna sidelobe radiation', Electron. Lett., 1978, 14, (11), pp. 343-345

The authors would like to make the following correction to their letter:

The following errors occurred in the printed text: In eqn. 3, the function Jo by a multiplication sign.

Eqn. 5 should read: nco kpc 2

2 sin a,-

2/3

(cos2 ac — cos2 a,-)

[(2TTA sin 0)/A]

was incorrectly split

In eqn. 4, the final exponential should be

IEE Electromagnetic Waves Series 5

ELF Communications Antennas

M. L. Burrows

The ELF band (30 to 300 Hz) has very serious deficiencies compared with the conventional radiocommunication bands if conventional communication is required. It has a very restricted bandwidth, implying low data rates, and a very large wavelength, implying inefficient and nondirective antennas. For special applications, however, involving some part of the propagation path being in conductive Earth media, such as rock, soil or water, it offers the possibility of communication where the conventional bands offer none. These include, for example, emergency communication between the surface and trapped miners, diver-to-diyer communication in the sea and communication with submerged submarines, both at short and long ranges. Like the applications themselves, the antennas available at ELF are mostly unconventional. They range from the vertical whip receiving antenna, through loops and horizontal grounded-end dipoles of various forms, to magnetometers.

454

The book presents, for the first time, a systematic review of these antennas. After an introductory chapter, there follow chapters on the theory of ELF radio propagation and on the basic operating parameters of ELF antennas. The two final chapters, comprising the bulk of the book, describe the different kinds of transmitting and receiving antennas and develop their design formulas. June 1978, 255pp, 71 diagrams, 216 x 135mm, casebound, ISBN 0 906048 00 1, price £11.50 UK, £13.50 Overseas (excluding the Americas) Inquiries, and orders with remittances should be sent to: Publication Sales Department, Peter Peregrinus Ltd., PO Box 26, Hitchin, Herts. SG5 ISA, England Orders for the Americas should be sentto:ISBS, PO Box 555, Forest Grove, Oreg. 97116, USA ELECTRONICS LETTERS

6th July 1978

Vol. 14 No. 14