US2029015A - Antenna - Google Patents

Description

Jan, 28, 193 60 O Cj 2,029,1115

ANTENNA 7 Filed Aug. 9, 1950 INVENIOR OTTO BO HM.

ATTORNEY Patented Jan. 28, 1936 ANTENNA Otto Biihm, Berlin, Germany, assignor to Telefunken Gesellschaft fiir Drahtlose Telegraphie m. b. H., Berlin, Germany, a corporation of Germany Application August 9, 1930, Serial No. 474,112 In Germany August 27, 1929 3 Claims. (01. 250-33) It is well known in the radio art that a bunching or beam effect is insurable by combining individual antennae. As a result it is possible to increase considerably the field intensity at certain points for the same transmitter power. Now, as long as transmission is to be effected towards a definite point bunching or beam action can be pushed to any desired degree both in the horizontal as well as in the vertical plane. However, if transmission is to be effected simultaneously in all directions of the compass, as in broadcast work, then recourse may be had only to a vertical beam. This is easily secured by the disposition of several individual antennae above one another. However, the possibilities in this regard are very limited. The present invention has an object the disclosure of antenna combinations whereby a vertical beam efiect is obtained without the constituent antenna thereof being superposed.

If along a circle having a diameter of a half wave length a number of separate antennae are suspended, and if these are fed at the same phase and amplitude, the horizontal radiations of pairs of opposite antennae become added in one direction, while the horizontal radiation at right angles thereto is zero. If the said antennae are uniformly distributed over the circle, then there exists no preferential direction, and this allows of the inference that the radiation in the horizontal plane is uniform all around. However, in the vertical plane in the case of a combination of two separate antenna being a half wave length apart, there occurs a reduction in the radiation. In this connection it is, fundamentally speaking, immaterial whether the constituent antenna radiate subject to vertical or horizontal polarization, whether they are long or short, or whether they themselves represent antenna combinations. The final radiation diagram invariably is the product of the diagram of the antenna combinations wherein the constituent antenna are assumed to be punctiform, and the diagram of an individual antenna. Instead of making the maximum distance between two constituent antenna equal to a half wave length, the same could also be increased to any desired whole multiple thereof.

Upon this basis a great number of combinations are feasible as shown for example in the accompanying drawing wherein,

Figures 1 to 5 illustrate various arrangements of antenna according to the present invention.

The simplest arrangement is the triangular form comprising only three constituent antenna such as shown in Figure 1. This scheme can be extended to include a polygon comprising any desired number of angles as in Figures 2 and 3, though also a perfectly circular form of the disposition of the constituent antenna is possible as in Figure 4.

Each of these all-round antenna combinations may be used for sending as well as for receiving. The most suitable point of mounting for trans mitter and receiver equipment, of course, is the center of the antenna system. Connection between the constituent antenna and the transmitter or receiver is insured by energy-supply or down-leads.

As shown in plan view in Figure 5, a plurality of vertical linear radiators A are coupled to transmitting or receiving apparatus T through lines L. The lines and coupling to the antenna and receiving apparatus are adjusted, as well known in the art, so that each of the elements A oscillates in phase or supplies cophasal currents to apparatus T.

I claim:

1. An antenna array comprising a plurality of linear radiators arranged around a circle and disposed at equal distances from a central nonradiating point, certain of said radiators being spaced apart from each other a distance equal to a whole multiple of one-half the length of the communication wave, and means for exciting said radiators cophasally.

2. An antenna array comprising a plurality of linear radiators disposed around a circle whose diameter has a length equal to a whole multiple of one-half the length of the communication wave, each of said radiators being arranged to be diametrically opposite another of said radiators, and means for exciting all of said radiators cophasally.

3. An antenna array consisting solely of a plurality of linear radiators, at least three arranged around a circle and disposed at equal distances from and surrounding a central nonradiating point, high frequency apparatus at said central point connected in circuit with each of said radiators, and means for exciting said radiators cophasally. n

OTTO 'BOHM.

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