Patent GB-592162-A (GB)
Title: Devices for the transmission or reception of ultra-high frequency electromagnetic waves
IPC: H01Q13/24
Filed: 1943-12-31
Abstract: 592,162. Wave - guides. WESTERN ELECTRIC CO., Inc. Dec. 31, 1943, No. 34748/45. Convention date, Nov. 28, 1941. Divided out of 592,120. [Class 40 (v)] A wave-guide, preferably comprising an unsheathed rod of solid dielectric material, is employed as a radiating or receiving aerial, energy being radiated or received' continuously along its length and its dimensions being such that the phase velocity of the guided wave approximately equals that of the space wave, whereby a maximum directional lobe is produced in an axial direction. Arrays of such aerials may be employed. In Fig. 1, a cylindrical polystyrene rod. 55 is enclosed at one end in a metal sheath 56 with end plate 57, and is energized by a wire 58 embedded in the rod. A tuner 59 is provided and the wire is energized by an oscillator .61 through a concentric line. The rod is supported by a clamp 62 on a pillar 60 and rotatable base 63. Optimum values for the diameter and axial length of the rod are discussed in the Specification. A rectangular guide rod aerial 55, Fig. 3, may be enclosed at one end in a metal sheath 66 and may be slotted to receive a slidable reflector 70, 71 which forms a number of sub-guides of such dimensions as to block transmission. The rod 65 may comprise a metal septum perpendicular to the electric vector E (Fig. 4, not shown). The inner end of the rod 65 may be tapered down to an edge perpendicular to the electric vector E, Fig. 5, and may enter a larger rectangular chamber 74 which may be divided by a slotted diaphragm 75. Impedance matching may be effected by choice of suitable dimensions for the chamber 74, and by axial adjustment of the rod 65 therein. The rod 65 may be of soft rubber to permit adjustment or oscillation of its axial direction, and this may be confined to a single plane and given a suitable natural period of vibration, by the metal septum embedded in the rod. Scanning in two planes at right angles may be provided for by the use of a metal rod core surrounded by dielectric material. Scanning may also be effected by interposing a coiled spring between the rod support 60, Fig. 1, and the base, and applying the drive through an escapement or other mechanical. device. To obtain more rapid scanning with higher gain and better angular definition, a number of rods 85, Fig. 8, are arranged radially in circular array, and a distributer 86 moving in a circular path connects a source 87 or a receiver to the ends of a group of rods. The distributer, Fig. 9, comprises radial wave-guides 91 of rectangular section leading to the ends of an arcuate portion 92 which has slots communicating with the flared ends of the rods 85. Energy is fed through a coaxial line 87 having its end section 88 rotatable on its own axis. The inner vertical walls of the guides 91 are connected to the outer conductor of the coaxial line, and the outer vertical walls' pass through the outer conductor into tangential contact with the inner conductor. Phasing loops 93 may be interposed between the slots 92 in the arcuate portion of the guide with the object of securing such phase relation between the waves in the respective active rods that a single sharp beam with a plane wave front a is produced. In an alternative distributer, Fig. 10, energy is fed through a circular guide 94 and emerges through slots 95 into a number of flaring radial guides 96 of rectangular section and thence through slots 92 into the coupling chambers of the radiating rods 85. Phasing may be effected by phase shifters 97 arranged in the outer pairs of the radial guides 96. Specification 592,120 is referred to.