US 2045398 A
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June 23, 1936.
A. MASSEY ET AL RADIO ANTENNA men/Lave:
Filed Aug. 9, 1934 INVENTORS Mmsafy HE/VAPY H222. /0/(.
Patented June 23, 1936 UNITED- STATES PATENT V OFFICE 2,045,398 RADIO ANTENNA Andrew Massey and Henry Hulick, Raleigh, N. C.
Application August 9, 1934, Serial No. 739,086 4 Claims. (01. 250 11) This invention relates to improvements in radio antenna: andvhasparticular reference to an apparatus for reflecting radio frequency energy from an emitter in alldirections parallel to the surface of the earth.
In the sending out of radio frequency energy by-the conventionalform of antenna, much-of the energy emitted travels in a skyward direction and is of practically no use in commercial radio broadcasting. Themain object of this invention is to reflect the radiation of the radio frequency energy from the emitter in such direction as to travel parallel to, and at a constant distance above the earths surface. This method of transmission eliminates all angular radiation and converts all the transmitted energy into ground wave where it will create amost satisfactory service area with minimum interference at a distance.
Another feature of the invention resides in a radio antenna which includes a cupped emitter;
Figure 1 is a diagrammatic view illustratingthe invention partly in side elevation and partly in section.
Figure 2 is a view similar to Figure 1, but showing the parts in reversed position.
Referring to the drawing by reference characters, the numeral l0 designates a conical diverter, the outer deflecting inclined surfaces ll of which are of a 45 degree angle and of any suitable metal such as steel, copper, or aluminum. In Figure 1 of the drawing, the flat base l2 of the diverter is shown as resting 'upon the earths surface A and the apex points skyward.
Supported above the top or apex of the conical diverter and in vertical axial alinement therewith is a hemispherical shaped bafiie and reflector [3, the walls of which are concavo-convex with the open side thereof facing away from the conical diverter.
Supported above the baffle I3 is a paraboloid reflector I4, the axis of which is in vertical alinement with the vertical axis of the diverter l0 and baffle l3 while the circumference of the same is the same or approximately the same as the base l2 of the diverter Ill. The reflector I4 is constructed of any suitable metal such as steel, cop-- per or aluminum and is concavo-convex with the concave side facing the conical diverter l0. The peripheraledge of the parabolical reflector I4 is on the same plane as the, circumferential edge of the hemispherical baffle i3 for a purpose to be presently explained.
Mounted centrally of the hemispherical shaped bafiie I3 is a radio'frequency energy radiator or emitter I5, which may be in the form of a solenoid with the windings of the coils extending equal distances from opposite sides of the axial center of the hemispherical baffle 13.
From the description thus far,.it will be under stood that the diverter I0, hemispherical reflector baffle I3, parabolic reflector I 4, and emitter I5 are arranged in vertical axial alinement with the bafiie interposed between the diverter and the parabolic reflector, while the emitter is cupped on the diverter side by the hemispherical baffle 53.
In practice, the radio frequency energy discharged by the radiator or emitter i5 is transmitted radially, the baffle 13 preventing the direct transmission of the energy to the conical di verter,.and reflecting them upwardly toward the parabolic reflector M, it being noted that the baffle is relatively small in diameter in compari' son with the diameter of the parabolic reflector I4 and the base of conical diverter it. The outwardly and upwardly diverted radio frequency energy shown by the lines I6 directly strike the curved reflecting surfaces of the parabolic reflector at an angle and are reflected with those transmitted from the reflector l3 in a downward vertical direction shown by the lines I! into the 3 path of the upwardly converging walls ll of the conical diverter l0. After striking the upwardly inclined walls of the diverter, the radio frequency l4, thence downwardly upon the diverter l0, and
is reflected from the diverter III in a direction to travel parallel to and at a constant distance above the earths surface. This eliminates all angular radiation and converts all the transmitted radio frequency energy into ground wave where it will create a most satisfactory service area with minimum interference at a distance.
In Figure 1 of the drawing, we have illustrated the apparatus with the base l2 of the cone rest-' ing upon the earths surface and the other parts supported thereabove. However, the entire structure may be reversed 180 degrees, as shown in Figure 2, so that the convex side of the parabolic reflector rests upon the earths surface while the base of the conical diverter is at the top. The same result is obtained so far as the transmission of the radio frequency energy is concerned, but the direction of reflection from the emitter I5 and reflector I3 is downwardly while the reflection from the parabolic reflector is upwardly onto the. elevated conical diverter In. In this position the ground waves are transmitted on a higher level than that shown in Figure 1. I
While we have shown and described what we consider to be the preferred embodiment of our invention, it will be appreciated thatv the parts.
have been shown more or less diagrammatic and we do not wish to restrict ourselves to various specific details of construction, but that such alterations and changes as come within the scope of the appended claims may be resorted to if desired.
Having thus described the invention, what weclaim as new and desire to secure by Letters Patentof the-United States, is:-
1. A radio antenna comprising in combination, a conical diverter, a parabolic reflector, said conical diverter and parabolic reflector being arranged in superimposed relation and with their center axes in vertical alinement, a radio frequency energy emitter interposed between said conical diverter and said parabolic reflector, and
a hemispherical baflie interposed between the.
onto the inclined surfaces of said conical diverter, and deflected radially and horizontally therefrom parallel to the earths surface.
3. A radio antenna, comprising in combination, a conical diverter, a parabolic reflector, a relatively small hemispherical bafile interposed between said conical diverter and said parabolic reflector and a radio frequency emitter positioned axially with respectto the bafile, said conical diverter, parabolic reflector and baflle beingarranged in vertical axial alinement, said baffle and parabolic reflector having their peripheral edges on a horizontal plane to prevent radiation of waves from the emitter without striking either the baffle or the reflector and said bafile and reflector further being arranged with their concaved faces opposed so as to concentrate all of the waves from the emitter against the inclined Walls of the'conical'di'verter for deflection radially and horizontally therefrom.
4. A radio antenna comprising in combination, a conical diverter, a parabolic reflector, a relatively small hemispherical baffle interposed Icetween said conical" d-iverter and said parabolic reflector; and a radio frequency emitter positioned axially with respect to the bafile, said conical diverter, parabolic reflector and baffie being arranged in vertical axial alinement, and said bafile and parabolic reflector having their peripheral edges on a horizontal plane so as to prevent radiation of waves from the emitter without striking either the baiile or the reflector.
' ANDREW MASSEY.