GB314310A - An improved system of aerial navigation, utilizing electromagnetic radiation - Google Patents

Abstract

314,310. Kolster - Brandes, Ltd., (Assignees of Kolster, F. A.). June 23, 1928, [Convention date]. Aerials; directive signalling to aircraft.-In a system of aerial navigation a conical space 14, Fig. 1, above a landing field 10 is circumscribed by an upwardly directed conical zone 13 of electromagnetic radiation produced by concentrating the wave-energy of a conductor, both spaces extending down to a point 11 on the field 10. An aerial 18, Fig. 5, placed along the axis 21 of a paraboloid reflector 16, of conductive material, sunk in the ground at 11, and energized by an oscillator 34 through a modulator 35 and amplifier 36, produces the substantially hollow cone-shaped radiation field 13. The wavelength employed is preferably four times the focal length of the reflector or the latter may be an odd multiple of a quarter wavelength. The radiation produced may be characteristically modulated. The inner solid cone 14 may be filled with radiation either of different wavelength or differently modulated, for example by speech currents for directing the navigator, by arranging a second aerial 31, Figs. 4, 5, in the form of a ring surrounding the reflector axis. Reactive phase shifting means 33, divides the conductor into two halves substantially equal in length to half the wavelength of the radiation employed, and possessing potential nodal points at their centres, to one of which the transmitter 32 is coupled. When employing only the hollow zone, the receiving aerial is correctly polarized if it is similar to the conductor 18 of the transmitter, and extends substantially parallel to axis 21. With the double zone method, an aerial independent of the polarization of the radiation. such as crossed conductors extending in a horizontal plane should be used.