GB589136A - Improvements in or relating to directive radio systems - Google Patents

Abstract

589,136. Wave guides; aerials. WESTERN ELECTRIC, CO., Inc. June 2, 1944, No. 10688. Convention date, June 5, 1943. [Class 40 (v)] In a directive radio system, a receiver or transmitter is connected through a switch to transmission channels connected to different points on an antenna system comprising at least one wave-guide for radiating and collecting waves. Fig. 1 shows a lobe switching arrangement for radar comprising a transceiver I connected by a coaxial line 2 to a main wayeguide 5, the end of which communicates by apertures 14 with two chambers 9, 10 separated by a partition 8 formed with an aperture 11 and rotatable detuning vane 12. Chambers 9, 10 communicate by apertures 21 with respective branch guides 16, 17 which connect with a guide 23 at points 29, 31 at a quarter wavelength from the ends. The guides 16, 17 and 23 are filled with polystyrene, and guide 23 is provided with transverse slots 26 to form a broadside antenna. The slot spacing is arranged to give a direction of maximum radiation at an angle # to the perpendicular to the longitudinal axis of the guide, # being positive or negative according to which end the energy enters or-leaves the guide. Thus, with chambers 9, 10 alternately detuned by rotation of vane 12, energy from transmitter 1 is alternately fed through guide 16 or guide 17 to opposite ends of guide 23 to give alternate lobes at an angle # to the broadside position. The reception pattern is similarly switched. The coaxial line 2 may include a flexible joint 37 to enable the antenna system to be rotated to face a target, this being indicated by the receipt of echo pulses of equal intensity. In Fig. 3, a transceiver 1 feeds through coaxial line 2 and main guide 5 to chambers 7 alternately detuned by rotating vane 12, which connect through guides 42 and coaxial lines 41 to opposite end of wave-guide antennas 23 similar to that in Fig. 1. The guides 23 are angularly displaced to give a desired angle between alternate lobes. Alternatively, the guides may be fed at adjacent ends. The Specification as open to inspection under Sect. 91 also includes the following matter. Fig. 5 (Cancelled) shows an antenna for simple broadside action, comprising a waveguide 45 filled with polystyrene and provided with transverse slots 26 arranged one wavelength apart, and facing a parabolic reflector 47. The antenna is energized by transmitter 1 through coaxial line 2. A similar broadside effect can be obtained by an air-filled guide having a longitudinal slot, and energized either at the middle or at one end, Figs. 6, 7 (Cancelled), not shown. Fig. 8 (Cancelled) shows an antenna for end-on effect comprising a wave-guide 80 filled with polystyrene and formed with a longitudinal slot 81, 82 in each side. This subject-matter is not contained in the Specification as accepted.