Wave antenna

Sept. 17, 1935.

C. E. SCHULER

WAVE ANTENNA Filed July 11, 1933

2,014,784

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Patented Sept. 17, 1935

2,014,784

UNITED STATES PATENT OFFICE

2,014,784

WAVE ANTENNA

Charles E. Schuler, Columbus, Ohio, assignor to International-Stacey Corporation, Columbus, Ohio, a corporation of Ohio

Application July 11, 1933, Serial No. 679,926

Claims.

(Cl. 250—33) tion, it provides for relatively simple erection by ordinary means.

A further object resides in the provision of an outrigger placed on top of the radiating portion of the tower from which there are suspended a number of wires which extend and are attached to the base of said radiating portion. This outrigger consists of a plurality of horizontal structural members suitably attached at or near the top of the tower and are bonded thereto for electrical efficiency.

An antenna made in accordance with my invention involves considerable reduction in ground space required with the resultant saving of cost _ for land, in comparison with the guyed structure reauiring large plots to accommodate guys or other secondary supports. Also, I use less expensive insulators than those used in guyed structures as well as a fewer number in order to further reduce cost.

For a further understanding of the invention, reference is to be had to the following description and the accompanying drawing, wherein:

Fig. 1 illustrates a side elevation of an antenna made in accordance with the present invention;

Fig. 2 is a plan view thereof;

Fig. 3 is a transverse horizontal sectional view on the line ΙΠ—IH of Fig. 1. „„

Referring more particularly to the drawing, the numeral I designates my improved antenna mast in its entirety. The portion of the mast from the plane indicated at B to the top of the mast constitutes the radiating portion of the tower. Electrical conductors S are connected with the lower part of the radiating portion of the tower and extend from the plane B down to the point C, converging from the lower part of the active antenna. The tower from the plane B to the ground forms the supporting portion and, electrically considered, is not a part of the active antenna.

The tower comprises preferably four corner upright members which may partake of the form of steel angles, as indicated at I', 2, 3 and 4. To provide necessary rigidity and strength, these angle member are interconnected by diagonals 5 and girts 6. In the preferred form of my invention, the leg members are placed on the corners of a square, as indicated in Fig. 3, and are inclined to the vertical forming a structure having a base larger than its top. At points intermediate the base and top of the tower, there are inserted suitable insulators 7, which serve to divide the tower into electrically isolated sections. At the base of the radiating portion of the tower are attached the wires § which form the lower part of the active antenna system. These wires or cables come to a point at the ground line and terminate at and _βθ are secured to a tension insulator 9. The electriThis invention relates to a vertical antenna suitable to radiate radio signals and its principal object is to improve the transmission thereof. A further object is to obtain an improved type 5 of a vertical antenna suitable for radiating electro-magnetic waves.

In radio broadcasting, it has been customary to erect two towers and connect them together by a horizontal wire. From this wire, there is 10 suspended a vertical cage antenna at half way between towers, and anchored to ground at the other end. The difficulties encountered heretofore with this arrangement are as follows:

(a) Antenna systems for the higher wave 15 lengths in the broadcast band become very costly on account of the very tall supporting structures which are required.

(b) The presence of the two towers distorts the broadcast pattern.

(_C) Power losses due to absorption of energy.

My invention obviates the above objections by providing a self-supporting mast or tower, the top portion of which acts as a radiator of electromagnetic waves and the bottom of which sup25 ports in addition a wire antenna bonded to the top portion of tower. The structure is mounted on insulators at the base and at intermediate points, and consists substantially of four or more leg members, interconnected by bracing mem30 bers. The upper or radiating portion of the tower is insulated from the lower supporting portion of the tower preferably at a point proportionally related to the length of the operating wave, whereby the insulated plane between the 35 tower portion will be theoretically at a minimum voltage value. Adjacent to the insulating plane, there are attached to the upper portion of the tower several wires which are brought to a point at the ground line, and are isolated therefrom 40 by a tension insulator of conventional construction. This group of wires forms the lower part of the antenna, and is connected to the coupling system of the¹ transmitter circuit. _

Other insulators are inserted into the tower 45 legs at various points to break up the tower into sections electrically insulated from each other. The length of these sections should preferably be not more than one-eighth of the operating wave to eliminate re-radiation of the supporting 50 structure. Making the radiating portion of the mast equal for instance to one-quarter of the operating wave, places the insulators such that they are subjected to a minimum amount of electrical strain, permitting the use of comparatively in55 expensive insulators of conventional design.

My invention provides an antenna tower in which mechanical stresses can be readily determined by ordinary methods used in mechanics and does not depend on secondary supporting ⁶⁰ means such as guy wires, or the like. In addi10 cal conductors 8 are arranged preferably on the sides of a polygon, as indicated in Fig. 3. Insulators ID are employed to isolate the lower section of the tower from the ground, or the cementitious &amp; foundation for the tower.

At or near the top of the radiating portion of I, antenna, there are provided radiating supports 11, functioning as a spreader frame, from which there are suspended substantially vertical conductors 14, the latter being attached at their lower ends to the base of the radiating portion of the tower immediately above the upper set of insulators 7. The conductors 14 are electrically bonded to the base and top of the radiating portion of the tower and are, therefore, an active part of the antenna. If desired, the wires 8 forming the lower part of the active antenna system may consist of continued extensions of wires 14.

The uppermost set of insulators 7 should preferably be inserted into the tower legs at a point proportional to one-fourth of the length of the operating wave measured from the top of the tower. This will put them at a point at which the voltage applied to the antenna system is theoretically zero in order to place a minimum electrical strain thereon. On a half wave antenna, therefore, these upper insulators should be inserted at a point half way of the height of the tower. This allows the use of comparatively inexpensive insulators and requires but a minimum of them. The insulators 7 inserted in the supporting portion of the tower should be preferably not farther apart vertically than one-eighth of 35 ‘-πθ operating wave of the antenna to prevent reradiation. It is to be noted that the antenna described herein may be constructed with the use of materials other than steel without departing irom the scope of my invention. Likewise the insulators 7 may be placed at other desired points than those specifically set forth.

The structure described requires but a miniinum of space to erect a high capacity antenna and is devoid of secondary supporting means such as guy wires and the like, which require additional ground space and add to the cost of the structure. The present antenna is simple to fabricate, erect and maintain and may be produced at a cost materially lower than comparable towers of which I am aware.