US2129852A - Antenna for an airplane with a metallic body - Google Patents

Description

Sept. 13, 1938. A. LEIB ANTENNA FOR AN AIRPLANE WITH A METALLIC BODY Filed Feb. 1, 1935 nun - ATTORNEY.

Patented Sept. 13, 1938 UNITED STATES PATENT OFFICE ANTENNA FOR AN AIRPLANE WITH A METALLIC BODY August Leib, Berlin, Germany, assignor to Telefunken Gesellschaft fiir Drahtlose Telegraphic m. b. H., Berlin, Germany, a corporation of Germany Application February 1,1935, Serial No. 4,465 In Germany January 3, 1934 Claims. (Cl. 250-33) This invention relates to an antenna for an a coupling coil E which is adapted to be assoairplane having a metallic body. It has been ciated with a radio apparatus K which may be a suggested in the earlier art (German Patent transmitter or a receiver.

No. 232,332) to utilize parts of an airplane itself I claim:

5 for the purposes of reception and transmission of 1. In an antenna system for aircraft compris- 5 electromagnetic waves in order that a distinct ing an airplane having a metallic body, an anantenna may be dispensed with and that air retenna formed from substantially the rear half sistance may thus be diminished. What was conportion of said metallic body whose cross-section cerned in the said earlier disclosure was a type forms a loop, an insulating member electrically of airplane the main surfaces of which consisted subdividing substantially the rear half of the me- 10 of canvass upon which, according of the above tallic body from the other half, said rear half German patent, metal foil was to be fixed at portion of the metallic body havinga longitudinal suitable places. slot located at right angles to said insulating Now, in the case of a metallic airplane such a member. method would be impracticable. While it is true 2. A loop antenna for an aircraft having a 15 that the metallic body of the airplane could be metallic body comprising a loop formed from the mechanically caused to oscillate as a dipole, this posterior half of said metallic body by substanwould primarily be possible only when used to tially dividing said metallic body in the central transmit or receive signals at its own natural portion thereof by an insulating member which period or wave-length. Also the attempt to inelectrically subdivides the posterior half from the 20 sure coil or loop antenna action of adequate inother half of said metallic body, and a slot extensity would be attended with some difiiculties. tending along the entire length of said posterior Now, according to the present invention these half of said aircraft body and located at right difficulties could be obviated by that the metallic angles to said insulating member.

body of the airplane is electrically subdivided. 3. A loop antenna for an aircraft having a 5 This invention will be better understood by remeta lic body Co p a 10010 formed from the ferring to the accompanying drawing, in which posterior half of said metallic body by substan- Fig. 1 is a perspective View of an airplane; tially dividing said metallic body in the central Fig. 2 is a section through the airplane body, portion thereof by an insulating frame member the section being taken on line MM, which electrically subdivides the posterior half 30 Such an electric subdivision of the metallic from the other half of said metallic body, a slot fuselage at right angles to the longitudinal axis extendng along the entire length of said posterior thereof is shown in Fig. 1. The two halves of half of said aircraft body and located at right metal A and B of the fuselage are firmly united angles to said insulating frame member, and an mechanically at the place marked C by a suffiinsulating rib member to reinforce the slotted 35 ciently strong wooden construction member L, portion of said body. providing electrical separation or insulation of the 4. A loop antenna for an aircraft having a two metallic parts. This insulation may be acmetallic body comprising a loop formed from the complished by the fact that the longrons of the posterior half of said metallic body by substanfuselage as well as the frame member or panels tially dividing said metallic body in the central 40 connecting them at C are made of wood. portion thereof by an insulating member which In order that a satisfactory loop antenna effect electrically subdivides the posterior half from may be secured, it is moreover recommendable to the other half of said metallic body, a slot exelectrically subdivide the entire metal fuselage or tending along the entire length of said posterior 5 rear part thereof to be used as an antenna by half of said aircraft body and located at right means of an oblong slot, the joints or edges of angles to said insulating member, and coupling which could be united in that case by means of means comprising a coil for coupling said loop' suitable solid insulators, e. g., also timber. Such antenna to radio apparatus.

a slot in the metallic portion is shown by S in the 5. In an antenna system. for an airplane havdrawing in the posterior end B of the metallic ing a substantially all-metal fuselage having a 50 fuselage. cross-section in the shape of a loop, a loop an- Fig.2 shows schematically a cross-section of the tenna formed by a portion of said metallic fusefuselage section to be employed as a loop anlage, said metallic fuselage being electrically subtenna taken on the line marked MM, of Fig. 1. divided by a lateral cross-section of insulating H denotes the wooden longe'rons here passing material, and the perimetrical continuity being 55 through the corners. D are metallic panels or broken by a longitudinal slot located at right ancovers. S is a slot, F a reinforcing rib of timber. gles to said insulating material Connected with the edges of the said slot S is AUGUST LEIB.

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