GB801886A - Improvements in or relating to systems for radiating ultra high frequency waves - Google Patents

Abstract

801,886. Aerials. COMPAGNIE GENERALE DE TELEGRAPHIE SANS FIL. May 7, 1956 [May 10, 1955], No. 14131/56. Class 40 (7). A radio aerial, comprises a primary element and a reflector in the shape of a cone or truncated cone of circular section, or the half of such a cone formed by cutting it by a plane through the axis. The primary element is located on the axis of the cone and the direction of its radiation and the apex angle of the cone are so correlated that energy radiated is reflected into a direction parallel to the axis. In practice the primary element or an array of such elements may extend along the axis and is preferably fed through the truncated apex end of the cone. Fig. 2 shows an extended axial primary element 2 in a conical reflector 6; the direction of radiation 4 being such that energy is reflected parallel to the axis xy as at 5. The element 2 may be a slotted waveguide or an end-fed plate aerial comprising a solid plate above which are mounted a stack of conductive perforated plates. The radiator may also be a plurality of coaxial parallel discs of varying diameter fed from one end by means of a horn (Fig. 5, not shown). In another embodiment (Fig. 6) a point source of radiation 14 on the axis of part cone 6 radiates energy on to a first reflector 18 of " cheese " type to form an extended secondary source 12-13 of parallel rays which are reflected parallel to the axis xy by the half cone 6. Specifications 751,046, 773,765 and 801,885 are referred to.