US2235015A - Antenna system - Google Patents

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` ANTENNA SYSTEM y Filed June 14, 1959 UNITED STATES `Pltl'fllltl'f OFFICE ANTENNA. SYSTEM Hans Eggers, Berlin, Germany, assigner to C. Lorenz Aktiengesellschaft, Berlin-Tempelhof, Lorenzweg, Germany, a company Application June 14, 1939, Serial No. 279,001 In Germany June 24, 1938 2 Claims. (Cl. 25u- 33) This invention relates to antenna systems, and ture that the antenna system will receive unimore particularly to antennas employed for wirefcrmly from and radiate uniformly into each less signalling on movable vehicles, such as airand every compass direction since the effective planes. directional characteristic thereof will not be in- .An antenna arrangement mounted on board iiuenced when the supporting surfaces are moved aircraft for receiving and/or radiating space out of the horizontal plane in response to a Waves customary consists of a vertical dipole deviation from the straight course line of flight. extended either upwards or downwards from the My invention will be more readily understood body of an aeroplane and connected with a wirefrom the following description taken in conjuncless receiver and/or transmitter through contion with the accompanying drawing, in which 10 ductors or cables, respectively. However, such Fig. 1 schematically shows an airplane which arrangement suffers under the fundamental disis provided with an antenna system according `to advantage that the electromagnetic eld received this inVentOn. While Fig. 2 shows radiation diaand/or radiated is considerably aiected by the grams explanatory 0f my invention.

l5 metallic structure of an airplane and in par- In Fig. 1 reference numeral l denotes the me- 15 ticular by the metallic supporting surfaces theretalliC strueture 0f an airplane An upper Verof, from which follows that neither the action tical dipOle 2 and a IOWer Vertical dilfJOle 3 dis'- of reception nor of radiation is uniform in the POSed in alignment With One another are inhorizontal plane, since instead of the desired sulatingly fixed on the upper respectively lOWer 2o circuler radiation diagrams considerably dispart of the airplane and are Connected preferably 2o torted diagrams are obtained which present one in parallel to a wireless receiving and/ 01 transor more maxima or minima, respectively. Such mitting apparatus 6 through Conductors 4 and distortion becomes still more harmful when the 5, reSDeCtiVelyairplane banks, that is, deviates from a, straight The different horizontal directional characline course in which case the supporting surteFistiCS 0f the antenna arrangement 0f Fig. 1 25 faces or wings on account of their deviation from are ShOWn in Fig- 2 The diagram a is that 0f the horizontal plane act as additional shieldings. the upper Vertieal dilOOle 2 alone and the diagram It is thus impossible to assure satisfactory wirel1' is that 0f the lOWer Vertical dipOle 3 alOne. less signalling or even to accurately determine The tWO diagrams d and b are nOtOngruOuS but the sense of direction of the electromagnetic the 0n@ is Substantially the true refleet-t0n 01 30 waves in eases that the antenna, means fol-m image of the other since the minimum of the one Dart Of a direction finding system. diagram is located almost in the maximum of Itis an object of my invention to provide means the other diagram. Because of the fact that in order to satisfactorily eliminate thedisadvanthe tWO Vertical dipeles Originating these diatages mentioned in the foregoing, and this is grams ate Connected in Parallel t0 the Wireless 35 achieved according to the main feature thereof Signalling apparatus, the resultant diagram C is by employing in an antenna, System 0f an airobtained which presents neither minima nor plane or the like n. plurality of antennas which maxima and which substantially involves circuare simultaneously effective and by so placing lar shape. Now, if the airplane differs from the these antennas partially on the upper and parstraight Course s0 that the supporting Surfaces 40 tially on the lower portion of the airplane that become inclined with respect to the horizontal the directional characteristics thereof mutually Plane, eaeli 0f the individual radiation diagrams supplement each other for securing reception is subjeeted t0 a Change but the resulting diaand/or radiation which is uniform in each and grain C 0f the tWO individual diagrams in 000i)- every compass direction, In gne specn aspect eration with one another remains substantially of my invention, the antenna system comprises unellanged- It is thus possible as a result 0f tivo individual antennas one of which projectthe novel antenna arrangement as proposed in ing upwards and the other of which projecting this invention to secure reception and/or radiadownvvards from the upper respectively lower tion which is uniform and equal in all 00mpart of the airplane. These two antennas are Dass direCtiOnS Whether the airplane nies on a 50 preferably vertical dipoles which in accordance straight course line or banks.

with a further feature of this invention are po- The facility according to this invention to sitioned in alignment the one above the other vertically mount the two dipoles in alignment above and below the airplane. one above the other involves the further advan- This novel facility involves the benecial featage that no additional directional action is set 55 up in the horizontal plane in response to transit time differences between the two individual dlpoles.

What is claimed is:

1. A wireless signalling equipment for use on board aircraft comprising a wireless signalling apparatus, an antenna system consisting of two individual antennas substantially omnidirectional in the horizontal plane of the craft one positioned above and the other disposed below said aircraft in substantially vertical alignment with one another and each normally setting up a radiation diagram subject to deformation by said aircraft, and means for connecting said upper and said lower antenna in parallel to the said Wireless signalling apparatus for simultaneous operation Whereby said radiation diagrams mutually supplement each other to produce a resultant radiation diagram of substantially circular configuration and uniform action in all compass directions.

2. The invention according to claim 1, characterized in that the said individual antennas are vertical dipoles.

HANS EGGERS.

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