Patent GB-683525-A (GB)
Title: Improvements in or relating to aerial systems
Inventor: CLOUGH NEWSOME HENRY
IPC: H01Q3/34
Filed: 1949-02-15
Abstract: 683,525. Aerials. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. Feb. 10, 1950 [Feb. 15, 1949; Feb. 23, 1949; Feb. 23, 1949], Nos. 4155/49, 4989/49 and 4990/49. Class 40 (vii). In a multi-segment loop aerial system two separate feeds F<SP>2</SP> and F<SP>1</SP> produce two independent modes of operation with no intercoupling, one mode producing circulating currents in the loop to give a substantially circular radiation pattarn in the plane of the loop and the other mode causing portions of the loop to function as a dipole or crossed dipoles to give a figureeight type of pattern also in the plane of the loop so that when the system is operated simultaneously in the two modes a cardioid radiation pattern is produced suitable for use in a rotating beam phase beacon (O.R.B.); in some of the embodiments, Fig. 1 and Fig. 5 (not shown), the aerial structure must be rotated physically and in others, Figs. 2 and 4 and Fig. 3 (not shown), rotation is effected electrically by means of a goniometer. If the frequencies applied to Fl and F2 are different, different intelligences may be transmitted simultaneously on the two modes. As shown in Fig. 1 a circular loop L is interrupted at diametrically opposite points A, A<SP>1</SP> and B, B<SP>1</SP> and radially inwardly extending conductors AC, A<SP>1</SP>C<SP>1</SP>, B<SP>1</SP>D<SP>1</SP> and BD are attached at the interruptions. The loop is operated in the second mode (figure - eight pattern) by connecting axiallyextending shorted #/4 two-wire lines CEC<SP>1</SP> and DFD<SP>1</SP> to the adjacent points C, C<SP>1</SP> and D, D', a two-wire feeder F<SP>1</SP> being connected to the mid-points of the shorting bars E and F and the system is operated in the first mode (circular pattern) by connecting axially extending shorted #/4 two-wire lines CGD and C<SP>1</SP>HD<SP>1</SP> to the diametrically opposite points CD and C<SP>1</SP>D<SP>1</SP>, a two-wire feeder F<SP>2</SP> being connected to the crossed shorting bars H and G. In a modification, Fig. 5 (not shown), the loop L is replaced by two coplanar sector shaped loops connected respectively between points C, C<SP>1</SP> and D, D<SP>1</SP>, the peripheral length of each loop being substantially #/2. According to the third Provisional Specification the angle of each sector is preferably 60-90 degrees. In Fig. 2, the loop is interrupted at four points AA<SP>1</SP>, CC<SP>1</SP>, BB<SP>1</SP> and DD<SP>1</SP>, the corresponding radial conductors being AE, A<SP>1</SP>E<SP>1</SP>, CG, C<SP>1</SP>G<SP>1</SP>, BF, B<SP>1</SP>F<SP>1</SP>, DH and D<SP>1</SP>H<SP>1</SP>, and for operation in the circular mode diametrically opposite points EF, E<SP>1</SP>F<SP>1</SP>, GH and G<SP>1</SP>K<SP>1</SP> are bridged by shorted #/4 two-wire lines EPTF, E<SP>1</SP>OSF<SP>1</SP>, GVRH and G<SP>1</SP>UQK<SP>1</SP>, the orthogonal shorting bars PT and VR being connected together and to the inner conductor, the coaxial feeder F<SP>2</SP> and the interleaved orthogonal shorting bars OS and UB being connected together and to the outer conductor of feeder F<SP>2</SP>. For operation in the figure-eight mode, the quadrantally disposed points EG<SP>1</SP>, FH<SP>1</SP>, E<SP>1</SP>H and GF<SP>1</SP> are bridged by shorted #/4 two-wire lines EMM<SP>1</SP>G<SP>1</SP>, FN<SP>1</SP>NH<SP>1</SP>, E<SP>1</SP>II<SP>1</SP>H and GJJ<SP>1</SP>F<SP>1</SP> and the two stators SC of a goniometer are connected between the midpoints of shorting-bars MM<SP>1</SP>, NN<SP>1</SP> and II<SP>1</SP>, JJ<SP>1</SP> respectively, a two-wire feeder F<SP>1</SP> being connected to the rotor RC. In a modification, Fig. 3 (not shown), the figure-eight mode is produced by bridging adjacent points EE<SP>1</SP> GG<SP>1</SP>, FF<SP>1</SP> and HK<SP>1</SP> by shorted #/4 two-wire lines, the goniometer stators being connected between the mid-points of the shorting bars corresponding to points EE<SP>1</SP>, FF<SP>1</SP> and GG<SP>1</SP>, HK<SP>1</SP> respectively; the feed for the circular mode is as in Fig. 2. In another embodiment, Fig. 4, the feed for the circular mode is equivalent to that of Fig. 2, quadrantally-disposed points E, G, F and H being connected by #/4 rods to points P, V, T, R on a wire ring and the quadrantally-disposed points El, G<SP>1</SP>, Fl and H<SP>1</SP> being connected by #/4 rods to the corners O, U, S, and Q of a square wire loop, the loop and ring being connected respectively to the two wires of feeder F2. For energization in the figure-eight mode, radial plates KW, Y<SP>1</SP>X<SP>1</SP>, YX and V<SP>1</SP>W<SP>1</SP> are inserted between the radial conductors and are capacity coupled therewith and the inner ends of diametrically-opposite plates are connected to the stators of a capacity goniometer via #/4 rods and low-impedance feeders F3 and F<SP>4</SP>. According to the second Provisional Specification the capacity feed for producing the figure-eight mode may be applied to a two-segment loop of the type shown in Fig. 1. In Figs. 1-4 the distance around each segmental portion of the loop is #/2 but the loop need not be circular as shown in the drawings. For use in a horizontally polarized phase beacon, the loop is mounted horizontally in a vertical cylindrical resonator having resonant longitudinal slots to prevent radiation of any vertically-polarized components and the whole or selected pairs of the axial #/4 lines may be enclosed in a common screen.