US2002197A - Directional aerial system - Google Patents

Description

May 21, 1935.

Hugh Freyuency Hp ms N. WELLS 2,002,197

DIRECTIONAL AERIAL. SYSTEM Filed Julfi; 23, 1931 INVENTOR- NORMAN WELLS' ATTOR EY Patented May 21, 1935 ArtNfrorFmE H DIRECTIONAL AERIAL SYSTEM Norman Wells, Sheen, London, England, as.-

signor to Radio Corporation of America, a corporation of Delaware Application July 23, 1931, Serial No. 552,611 In Great Britain August 16, 1930 4 Claims.

This invention relates to directional aerial systems and more particularly to aerial systems for use in so-called beam systems, i. e. systems in which a more or less concentrated beam of energy is propagated.

The invention has for its object to provide a beam aerial system which shall be simple in construction and arrangement.

According to this invention, a beam aerial system comprises a plurality of spaced radiating wires, a horizontal feeding wire or system adapted to energize said radiating wires, a single feeder for feeding energy to said horizontal feeding wire or system and means inserted between said horizontal feeding wire or system and one or more of the radiating wires whereby said wires are caused to be energized in a desired phase relationship necessary for producing a desired direction and concentration of propagation.

Preferably, the radiating wires are arranged in a plane at a. half wave length separation and those wires which are separated from the single feeder by zero distance or multiples of a wave length (measured along the horizontal feeding wire) are loaded at their bases each with a phasing element equivalent to an inductance one half wave in length. l

The invention is illustrated in the accompanying drawing which shows in schematic perspective one arrangement in accordance with the invention.

Referring to the drawing, a beam aerial system comprises seven vertical radiators R1 R2 R3 R4 R5 R6 and R7 spaced apart in a plane by distances of half a wave length between radiators,

the centre radiator R4 and the two radiators R2 and Re which are spaced one wave length therefrom being loaded at their bases each withan inductance L2 L4 or L6 equivalent to half a wave length of horizontal feeder; the other radiators are unloaded. The seven radiatorsare connected together at their bases by a horizontal feeding wire FW whose middle point (i. e. the point to which the leading inductance for the central radiator is connected) is directly connected to a single wire feeder WF. The provision of the loading inductances in this arrangement causes all the aerials to be supplied with current in the same phase with the result that a beam substantially at right angles to the general plane of the aerial system is propagated when said system is energized. Any convenient horizontal feeder system may replace the wire F'W, for example a concentric feeder with the outer conductor earthed may be employed.

It is preferable, though not absolutely necessary so to dimension all the feeder conductors that the effective resistances at the junctions are matched in order to avoid reflection at the said junctions.

It will be appreciated that the construction above described is comparatively simple and moreover it possesses the substantial advantage that since there is only one feeder and this is centrally arranged it is a relatively easy matter 10 so toarrange and construct the system that it may be rotated about its centre so as to vary the direction of propagation.

It will also be appreciated that the separation between vertical aerials need not be half a wave 15 length provided that the phasing elements bear the correct relation to the distance between zero, i. e. the centre point, and the points of attachment.

Obviously the nature of the radiators employed is capable of considerable modification according to the result desired. For example, an improved concentration may be obtained from an installation as above described if each radiator, instead of being a simple wire, is constituted by an aerial long in comparison with the wave length employed which is so constructed (in manner known per se) that radiation from alternate half wave lengths is suppressed or substantially reduced.

Having thus described my invention, what I claim is:

1. A beam aerial system comprising a plurality of radiating wires spaced apart in a plane and separated from one another by a distance equal to one half of the working wave length, a horizontal feeding system adapted to energize said radiating wires, a single feeder for feeding energy to said horizontal feeding system, said horizontal feeding system being connected directly to the bases of those radiating wires which are separated from the single feeder by distances equal to a half wave length or an odd multiple of the half. wave length and through phasing elements equivalent to an inductance of one half wave length in length tothe bases of those radiating wires which are separated from the single feeder by a distance equal to an even multiple of the half wave length, and to the base of that radiator which is situated at zero distance from the single feeder substantially as described.

2. An aerial system having, in combination a plurality of parallel vertical spaced aerials, a substantially horizontal feeder system individually connected to said aerials, a single transmission line connected to said feeder system, and reactance means inserted between said horizontal feeder system and alternate ones of said radiating wires whereby a desired phase relationship is obtained, by virtue of their spacing from one another and the value of said reactances.

3. An aerial system having, in combination, seven vertical parallel aerials in asingle plane spaced one half wave length apart from oneanother, a horizontal transmission line connected individually to each of said wires at the bottom thereof, another transmission line connected. to

said first transmission line at a point midway between the outermost aerials,andp'hasing elements NORMAN WELLS.

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