US2650984A - Wireless aerial - Google Patents

Description

P. MAN DEL WIRELESS AERIAL Sept. 1, 1953 Filed Dec. 28, 1950 IN VEIVTOR (fa/Q 1 fl, W MW Patented Sept. 1, 1953 WIRELESS AERIAL Paul Mandel, Paris, France, assignor to La. Radio- Industrie S. A., Paris, France, a body corporate of France Application December 28, 1950, Serial No. 203,150 In France January 18, 1950 2 Claims. (Cl. 250-33) The present invention relates to improvements in the construction of wireless aerials, whether for transmitting or receiving, with the object of providing the following improvements: simplicity in construction, a strong mechanical mounting, and radio-electrical efficiency; irrespective to whether they comprise a single radiator element or a pair of elements energised in phase opposition, or again a plurality of such pairs of elements.

In my invention the entire aerial structure, including the mast and the radiator elements, is formed without the use of insulators or dielectric parts.

In other words according to the invention I provide a wireless aerial of unitary structure without any insulating portions or parts, which comprises in combination a rigid conducting mast, a conducting self-supporting sleeve having a height substantially equal to a quarter of the working wave-length around this mast and affixed thereto at one end so as to provide between said mast and the free end of said sleeve an annular slot, namely two circular edges, one defined by the edge of the sleeve, the other by any circular line on the mast in the neighbourhood of the free edge of the sleeve, a radiating conducting element surrounding the mast and being fixed at one end to one edge of said slot and diverging from said mast to a spacing of its other end substantially equal to a quarter of said working wave-length, so as to maintain free said annular slot, a rigid supporting conducting memoer oi the same length of a quarter working wave-length joining said spaced end of the radiating element to said mast, and means for feeding the aerial or picking-up its received energy.

It is moreover possible for the said radiator structures to consist of rod-like conductors or of a solid wall, this plurality of conductors or this wall then defining a surface of revolution around the axis of the mast. Furthermore it is possible for the said rigid quarter-wave supports to consist of conductors or of a solid disc (of quarterwave radius or very slightly greater).

An aerial according to the preceding paragraph, but comprising two radiator parts operating in phase opposition, is then provided by the above combination in a unitary mounting but incorporating two conducting aerial elements, one of which is fixed to th mast and the other to the sleeve, the fixing of one element to the mast being effected in the immediate vicinity of the free end of the sleeve and the element fixed to the sleeve surrounds the sleeve.

It is possible according to the invention to form aerial arrays on the same conducting mast which pairs of radiator elements operating in phase opposition are fixed on the mast, and, in which the fixing spacing on the mast is reduced to a minimum between the adjacent terminal quarter-wave supports, so that these pairs of aerials are, in fact, coupled by quart-enwave lines; one of the pairs being energised.

It is to be understood that elements having an electrical length equal to any uneven multiple of this quarter-wave may be substituted for the above-mentioned quarter-wave elements.

The invention is illustrated diagrammatically by way of example, in the accompanying drawing wherein:

Figs. 1 to 3 illustrate aerials having transmitting or receiving surfaces in the form of train cated cones;

Fig. 4 relates to cylindrical surfaces;

Figs. 1 and 2 illustrate structures having single transmitting or receiving radiator in the form of a truncated cone;

Fig. 3 illustrates an aerial with two pairs of superposed elements in the form of truncated cones;

Fig. 4: illustrates an aerial having two coupled radiators in the form of cylinders; and

Fig. 5 illustrates a modification for energising aerials taken in relation to the method of energising shown in Fig. 1.

It is to be understood however that these radiator surfaces are only the direct extension, by rotation of the director, of conducting elements taken in one or more planes passing through the mechanical axis of the system.

In these figures, similar reference numerals denote similar parts.

Referring to the drawings, more particularly to Figs. 1 and 2, on a rigid conducting mast i there is mounted, by direct mechanical and electrical connections, without the use of insulation of any kind, a radiator, preferably having a surface of revolution.

A rigid metallic sleeve 2, having an electrical length which is substantially equal to a quarter of the working wave length of the aerial, or to an uneven multiple of this quatrer-wave length, is directly connected at one end to the mast l. The radiator is energised, for example by a connection, between the mast l and the sleeve 2, comprising an exterior conductor 3 with which is coaxial an inner conductor 4. The exterior conductor 3 of the coaxial connection is connected to the sleeve 2 at a place where there is an opening through which the interior conductor 4, connected to the mast I, passes.

To the mast I, in the vicinity of the periphery of the sleeve 2 there is fixed, or formed integral therewith, a truncated cone 5, the directrix of which is of a length substantially equal to a half-wave length, and the conicity such that at its free end, each point of its periphery is spaced by a quarter-wave length (or by an uneven mul tiple of the quarter-wave) from the surface of the mast I. The fixing of the transmitting or receiving surface 5 to the mast is then effected by a conducting support 6, a solid disc for example, of diameter slightly greater than a half wave length (by the thickness of the mast) fixed on the one hand to the periphery of the cone 5 and on the other hand to the end of the mast I. This conducting support 6 thus oifers no conductibility for the high-frequency current to flow from the mast to the outer periphery of the radiator.

In another arrangement shown in Fig. 2, the truncated cone 5 is inverted over the sleeve 2, being fixed to the periphery of the sleeve.

When it is desired to produce a balanced aerial, for example according to Fig. 3, considering one of its halves, or according to Fig. 4, it becomes necessary to couple two transmitting or receiving elements and, because these elements are energised in phase opposition, it is simple to combine the radiators of Figs. 1 and 2, by assembling together their common elements, the element 5' being fixed to the mast at a place adjacent to that where the sleeve 2 is fixed. The energy is still applied to the single element comprising the above-mentioned sleeve 2.

The superposition of such couples of radiator elements, as shown in Fig. 3, permits of obtaining the desired total height of the aerials; in eifect, by the provision of the terminal quarterwave supports, the juxtaposition, supports face to face, of two aerial elements, ensures the auto matic production of a quarter-wave transmission line I, from one aerial to the other, therefore for automatically placing them in phase for transmission or reception.

It is to be understood, as shown in Fig. 4, that the surfaces of revolution need not be in the form of truncated cones; for example, they may be cylindrical, for example as surfaces 9 and i0, fixed respectively to the sleeve 2 and the mast i by rounded surfaces H and i2.

The energising conductor has been shown, Fig. 1 and Fig. 2, as connected externally to the mast; it is to be understood that if this latter is of sufficient diameter and made hollow, this conductor can, as shown in Fig. 5, be led through the interior of the mast l.

The only condition the feeder 3, 3 of parallel currents has to satisfy is to be connected by one of its conductors to the mast and by the other to the sleeve. This feeded has been shown coaxial but it may as well comprises two parallel feeding wires under a screening sheath. The position outside the mast or inside the mast (see Fig. 1 and Fig. 5) is unimportant.

I claim:

1. A wireless aerial comprising in galvanic interconnection a rigid conducting mast to which is connected one conductor of a feeder pair, a rigid quarter-wave conducting coaxial sleeve surrounding said mast and being connected to the other conductor of said pair, said sleeve being shorted at one end to said mast, a first rigid half-wave radiator structure surrounding a linear portion of said mast and being affixed to the edge of the free end of said sleeve, a second rigid half-wave radiator structure surrounding an adjacent linear portion of said mast and affixed to said mast along a circular line near the edge of the free end of said sleeve, both of said radiator structures being of same overall revolution shape around the axis of said mast and diverging from said mast in oppoiste directions so that their respective remote ends each are a quarter wave-length distance radially from said mast, and rigid planar conducting supports joining said remote ends to said mast.

2. A wireless aerial comprising in galvanic connection a rigid conducting mast to which is connected one conductor of a feeder pair, a plurality of rigid quarter-wave conducting coaxial sleeves surrounding linear portions of said mast at spaced locations along said mast, each sleeve being shorted at one end to said mast, one of said sleeves being connected to the other conductor of said pair, a first rigid half-wave radiator structure surrounding each sleeve and being ailixed to the edge of each of said sleeves and diverging around said sleeve so that its remote end is a quarter wave-length distance radially from said mast, a planar rigid conducting sup port joining said remote end to said mast, a second rigid half-wave radiator structure surrounding a linear portion of said mast adjacent the free end of each sleeve and being afixed to said mast on a circular line near the free end of each of said sleeves and diverging from said mast in opposite direction with respect to the first radiator structure so that its remote end is a quarter wave-length distance radially from said mast, and a planar rigid conducting support joining said remote end of each second radiator structure to said mast, the planar conducting supports of adjacent radiator elements in adjacent pairs of radiators being spaced apart by a relatively small spacing along said mast.

PAUL MANDEL.

References Cited. in the file of this patent UNITED STATES PATENT! Number Name Date 2,239,724 Lindenblad Apr. 29, 1941 2,241,582 Buschbeck et al. -1" May 13, 1941 2,284,434 Lindenblad May 26, 1942 2,486,589 Chu Nov. 1, 1949 2,493,514 Wehner Jan. 3, 1950 2,501,020 Barnes Mar. 21, 1950

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