Echelon antenna

An Echelon antenna is a directional antenna that serves as a transmitting and receiving antenna in the frequency range from approx. 1  MHz to approx. 1 GHz. It belongs to the group of long-wire antennas and was discovered in 1931 by Carter et al. First described under the name Antenna Model B. In January 1938 a further description was given in the American amateur radio magazine Radio by W2DFN.

Structure and description

The radiation from two parallel long-wire antennas, at a distance of about λ / 2 or half the wavelength , which are excited in phase opposition, cancel each other out in the direction perpendicular to the plane of the wire. The radiation reaches a maximum in the wire plane. There are four main lobes or two bidirectional main lobes with the maximum value of the radiation in the wire plane.

If one wire is displaced by a certain amount (S) with respect to the other, one of the two main bidirectional lobes is canceled. As a result, a bidirectional main lobe remains; namely the main lobe, which points in the direction of the long wire lying further forward.

Calculation of the Echelon antenna:

D = distance between the parallel antenna wires in m

S = displacement in m

f = frequency in MHz

α = main ray angle in °

${\displaystyle D={\frac {150\cdot \sin \alpha }{f\cdot \sin \mathrm {2} \alpha }}}$

${\displaystyle S={\frac {150\cdot \cos \alpha }{f\cdot \sin \mathrm {2} \alpha }}}$

literature

• Rothammels Antennenbuch , DARC Verlag GmbH, Baunatal 2002, ISBN 3-88692-033-X , pp. 251f.

Individual evidence

1. ^ PS Carter, CW Hansell, NE Lindenblad: Development of Directive Transmitting Antennas . Proceedings of the IRE , October 1931, pp. 1773 to 1842 .