GB1294024A - Improvements relating to aerial arrangements - Google Patents

Abstract

1294024 Aerials EMI Ltd 19 April 1971 20460/70 Heading H4A An aerial arrangement is constructed by printed circuit technique, in which a metallic pattern is formed adhering to an insulating substrate, and comprises one or more arrays of aerial elements. An associated strip conductor is spaced from each array, and energy is fed to or from each element by mutual coupling, not involving any physical connection. As described, a dielectric board 1, originally coated on both faces with copper, has one face etched to form the pattern shown, the other face 2 being left untreated for use as a ground plane. The pattern comprises six strip conductors 3 to 8, each terminating at one end in a single strip conductor 9. A co-axial feed cable is connected to the end 11 of the conductor 9. The other ends of the conductors 3 to 8 are formed with orthogonal portions as shown and are terminated in lossy loads, such as films of lossy rubber. Each conductor 3 to 8 is associated with six dipole aerial elements such as the one shown at 10. The degree of coupling between the elements and the strip conductors is dependent upon the proximities of the elements to the conductors, and upon the impedances of the. elements. Control of the degree of coupling may also be achieved by varythe width of a strip conductor, the elements being positioned at equal or varying distances therefrom (Figs. 2, 3, not shown). Elements may be arranged co-linearly, with the strip meandering to vary the coupling (Fig. 4, not shown). In other arrangements elements are disposed alternately on either side of a strip conductor (Figs. 5, 6, not shown). Two simultaneous beams may be obtained with a single signal input if two arrays of similar aerial elements are arranged on each side of a conductor strip, if the element-to-element spacing of one array is different from the other (Fig. 7, not shown). In a somewhat similar arrangement, dual-frequency operation is achieved by having the elements of one array larger than those of the other (Fig. 8, not shown). Elements may be specially shaped to influence the aerial bandwidth (Figs. 9, 10, not shown).