GB586085A - Shielded loop antenna - Google Patents

Abstract

586,085. Aerials. STANDARD TELEPHONES & CABLES, Ltd. Nov. 10, 1944, No. 22162. Convention date, Nov. 15, 1943. [Class 40 (v)] A shielded antenna in the form of a gapped loop, designed to produce uniform radiation of plane polarized waves, and which may be fed by an unsymmetrical line, comprises four radiating members 10, 11, 12, 13 formed of hollow conductors, from the mid-points of each of which hollow supporting arms extend inwards to a common junction box 5. A concentric feeder 19 has its outer sheath 18 fixed to the box to serve as a support for the antenna. Members 10, 11, 12, 13 form a closed figure such as a square, adjacent ends being spaced apart by small gaps 1, 2, 3, 4. Connected to the centre lead of feeder 19 are four conductors 20, 21, 22, 23 extending outwards centrally within the four supporting arms to the mid-points of the corresponding radiating members and then turning, all in the same direction, centrally along the members and across a gap so that their free ends such as 30 are in the adjacent member. The radiating members are made less than a half-wavelength long and the free ends of the inner conductors, such as 30 form a tuning stub in conjunction with the outer members in which they lie. The length of the conductors is adjusted to tune the antenna. A preferred construction using junction boxes at 5, 42, 52, 62, 72 is indicated, and alternative geometric arrangements of the antenna given in Figs. 4, 5 and 6 (not shown). Specification 586,080 is referred to. The Specification as open to inspection under Sect. 91 describes also an antenna of circular' form with three radiating elements,. Fig. 7 (Cancelled and not shown). This subjectmatter does not appear in the Specification as accepted.