US1821380A - Transmitting or receiving aerial system for wireless telegraphy or telephony - Google Patents

Description

"Sept. 1 1931 c s. FRANKLIN 1,321,330

TRANSIEITTING OR RECEIVING AERIAL SYSTEM FOR WIRELESS TELEGRAPHY OR TELEPHONY Original Filed Feb. 17 1925 0 o 2 o W, O C 0 0 C2 "'7 Qvwntoz 4 CHARLES S. FRANKLIN Patented Sept. 1, 1931 UNETED STATES PATENT OFFICE CHARLES SAMUEL FRANKLIN, OF BUCKHURST HILL, ENGLAND, ASSIGNOB TO RADIO CORPORATION OF AMERICA, A CORPORATION OF DELAWARE- TRANSMITTING OR RECEIVING AERIAL SYSTEM FOR WIRELESS 'TELEGBAPHY OR TELEPHONY Application filed February 17, 1926, Serial No. 88,761, and in Great Britain February 24, 1925. Renewed January 31, 1931.

This invention relates to improvements in transmitting or receiving aerial systems for wireless telegraphy or telephony.

It is known that if an .aerial is placed at the focus of a parabolic reflector which is formed of a number of vertical wires, then a concentration of energy takes place and the electromagnetic waves are projected in the form of a beam, thedegree of concentration being largely determined by the size of the reflector relative to the wave length.

I have described in British specification No. 128665, July v3, 1919, how improved results can be obtained by making the reflector of a number of tuned wires placed one above the other.

Unless such a reflectorbe very large in both directions, relative to the wave length, it is not possible to obtain a very high degree of concentration.

Consider, for instance, a reflectingsystem made of a number of rods approximately wave length long, arranged as aparabolic cylinder about an aerial at the focus. As

1 the parabola is extended by adding rods, the

aperture of the parabola is increased and a greater degree of concentration results. It is obvious, however, that as the distance of the reflecting rods from the focus increases, so the percentage of energy radiated from the aerial in that direction which is reflected by the reflecting rod becomes smaller and smaller. In practice a limit is soon reached beyond which no appreciable improvement is obtained by further increasing the aperture of the reflector. I

According to this invention I provide two or more parabolic reflectors, arranged on a line at right angles to the axis of each reflector, so that their axes are parallel, or substantially so, to one another. If the oscillations fin-the .aerials at the focusof each reflector 'be maintained in phase, then the reflectors act together, resulting in an effective concentration proportional to the combined apertures of all the reflectors, without loss of efficiency.

This method of using a number of parabolic reflectors side by side, makes it possible to obtain concentration of the energy substantially proportional to the total apertures.

thus be obtained by employing the requisite number of parabolic reflectors, and such concentration may exceed that which is practical to obtain from a single parabolic reflector of the same aperture.

The oscillations in the aerials at the focus of each reflector may be maintained-in phase with each other by being fed through a cable system from a common transmitter.

The cables to each aerial should have equiva The aerials A1 and A2 are preferably ofthe type described in my application No. 47232 filed July 31, 1925, but they may be simple aerials and may be earthed, or the whole system of aerials and reflcctorsmay be arranged at a height above the ground.

High frequency energy is conveyed to the aerials by means of feeding wires or cables F1, F2 and F3. C1 and C2 are coils sit uated at the ends of the feeders F1 and F2, and are coupled to the aerials A1 and A2. The degree of coupling to the aerials should be equal and for the best efliciency should be such that no reflections take place along F1 and F2. The feeders F1 and F2, which should be electrically equal to each other, are connected through a transformer T to the feeder F3 which conveys the high frequency energy from the high frequency generator which may be located in any convenient position. The transformer T is preferably adjusted so that no reflections take place from this point back along the feeder F3. I I

If the conditions are correctly fulfilled,

Any desired degree of concentration can CJI then the high frequency oscillations produced in the aerials A1 and A2 will be in phase with one another, and the waves emitted by the two para-bolic'systems will act together so as to produce in the desired direction a concentration of energy substantially proportional to the sum of the apertures of the separate reflectors.

Any number of separate reflectors may be combined in the manner described above for two reflectors, while such a system of combined reflectors may be utilized for reception as well as for transmission.

Having described my invention what I claim is:

1. A directional aerial system comprising a plurality of parabolic reflectors arranged side by side, with substantially parallel axis, and an aerial at the focus of each reflector, all of the aerials being maintained in the same phase so that a directional concentration of energy is obtained.

2. A directive aerial system comprising a plurality of parabolic reflectors arranged side by side, an'aerial at the focus of each' reflector, all of the focal aerials being maintained in the same phase so that the concentration of energy radiated is substantially proportional to the sum of the apertures of the reflectors.

3. A directional aerial system comprising aplurality of parabolic reflectors arranged on'a line at right angles to the axis of each reflector, so that their axes are substantially parallel to one another, and an aerial located at the focus of each reflector,

each aerial being maintained in the samephase so that a directive concentration of energy is obtained. 4. A directive aerial system comprising a plurality of parabolic reflectors, each reflector having an aerial. at its focus, all the focal aerials being maintained in the, same phase so that a'directional concentration of energy is obtained, and a common means to excite said aerials.

5. A directive aerial system comprising a plurality of parabolic reflectors, each reflector having an aerial at its focus, all the focal aerials being maintained in the same phase so that a directional concentration of energy is obtained, and a common means to excite said aerials, comprising a transmission line so arranged as to prevent reflection of the energy passing through it.

6. A directive aerial system comprising a plurality of reflectors arranged on a straight line at right angles to the center line of each reflector, each reflector comprising a plurality of conductors arranged on a curve, an aerial on the center line of each reflector, and means to excite said aerials in predetermined phase relationship.

7. In a directive aerial system a plurality of cylindrical parabolic reflectors located adjacent each other, said reflectors each being composed of a plurality of spaced tuned wires or rods, an aerial located at the focus of each reflector, and a single means to excite said aerials in a predetermined phase relation.

7 8. In a directive aerial system, a plurality of primary aerials located adjacent each other, tuned reflecting means associated with each of said primary aerials, said tuned reflecting means comprising a plurality of conductors arranged on a curve, and non-reflective means for feeding energy to said primary aerials.

9. A directive. aerial system comprising a plurailty of associated parabolic reflectors, each reflector having an aerial consist ing of a linear conductor at its focus, all the focalaerials beingmaintained in the same phase so that a directional concentration of energy is obtained.

'10. In a directive aerial system a plurality of associated parabolic reflectors, composed of a plurality of spaced tuned wires'or rods, an aerial located at the focus of each reflector, and inductance coil coupled. to each of said aerials, feelers connected to each of said coils, a transformer connected to said feeders and means to feed high frequency oscillations to said transformer.

11. In a directive aerial system a plurality of parabolic reflectors, composed of a plurality of spaced tuned wires or rods, an aerial located at the focus of each reflector. and inductance coil coupled to each of said aerials, feeders of equal electrical length connected to each of said coils, a transformer connected to said feeders and non-reflective means to feed high frequency oscillations to said transformer.

12. In a directive aerial system a plurality of parabolic reflectors, composed of a plurality of spaced tuned wires or rods, an aerial located at the focus of each reflector. and inductance coil coupled to each of. said aerials, feeders connected to each of said coils, a transformer connected to said feeders and means to feed high frequency oscillations to said transformer, said feeds ers and said transformer being so arranged that no reflection takes place therefrom.

13. In a directive aerial system, a plurality of adjacent symmetrical curved reflectors, each reflector comprising a plurality of tuned conductors, an aerial located on the axis of symmetry of each reflect-or and common non-reflective means to excite each of said. aerials in predetermined phase relation.

14. In a directive aerial system, a plurality of symmetrical reflectors each comprising a plurality of conductors arranged on a curve, said reflectors located on a line perpendicular to their respective axes of symmetry, a focal aerial located on each axis, and common inductive means for energizing said aerials.

15. In a communication system for the transmission or reception of electromagnetic Wave energy, a plurality of independent radiant systems, each system comprising a primary antenna and a reflector partially enclosing the antenna, said systems being placed adjacent each other on a straight line substantially perpendicular to the desired direction of radiant action.

16. In combination, in radio signaling apparatus utilizing electromagnetic Wave phenomena, a plurality of independent, physically separated radiating systems, each independent system comprising a radiating antenna and a reflector therefor, each reflector comprising a plurality of conductors spaced apart in a direction transverse to their longitudinal dimension, said systems being arranged on a straight substantially horizontal line such that their independent radiation characteristics are substantially parallel in a substantially horizontal plane.

17. In combination, in a communication system utilizing electromagnetic Wave phe nomena, a plurality of physically separated radiant responsive systems arranged on a straight substantially horizontal line in a fashion such that their radiant characteristics are substantially parallel in substantially a horizontal plane, each radiant responsive system comprising a primary oscillating system and a reflector comprising a plurality of oscillators parallel to the primary oscillating system, and means coupling each primary oscillating system to high frequency apparatus whereby the action of the combined radiant responsive systems results elfectively in a sharper char-.

acteristic in a substantially horizontal plane than the characteristic of each radiant responsive system taken independently.

CHARLES SAMUEL FRANKLIN.

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