GB682115A - Dielectric antennae arrays - Google Patents

Abstract

682,115. Aerials. BOUIX, M. Aug. 18, 1950 [Aug. 19, 1949; Aug. 17, 1950], No. 20488/50. Class 40 (vii). In an aerial array comprising a plurality of dielectric rods coupled to a rectangular waveguide at intervals along its length by means of apertures spaced along the length of one face of the guide, the spacing of the apertures is less than a wavelength in the wave-guide, but is so related thereto that a given number of rods forming a group occupy an integral number of wavelengths of the guide, while the dielectric rods are all coupled to their respective apertures through delay means which introduce such different delays for the different members of a group that all the rods radiate cophasally. As shown in Fig. 1, a group of three rods occupies two guide wavelengths. The dielectric rods are mounted within cylindrical segments 2, 12, 22 ... which also incorporate the delay means. For the first rod of each group 1, 31 ... the delay is introduced solely by the material of the dielectric rod within the segments 2, 32 ... ; for the other rods, additional portions of dielectric material 8, 9 are inserted in the segments to effect the necessary delays. The portions 8 inserted in the coupling for the second rod of each group is also arranged to behave as a halfwave transformer, while the portions 9 inserted in the coupling for the third rod of each group is arranged as a three half-wave transformer. Matching screws 5, 15 ... are arranged opposite their respective apertures 4, 14 .... Fig. 4 shows an array wherein a group comprises two dielectric rods, the spacing between the rods being equal to one-half the guide wavelength. In order to effect cophasal energization, alternate circular segments 29 and 39 are constructed with different diameters so that the phase velocities of waves in alternate segments differ so as to effect the necessary phase correction. The energy supplied to the array may be uniformly distributed to all the radiating elements; alternatively, the energization may be " tapered."