Abstract: The present invention relates to a microribbon/wave guide line transition, especially between an antenna (1) of the plate antenna type, with radiating elements (3) and feed lines (4) printed on a face of a substratum (2) and a wave guide or a resonant cavity (12) with a rectangular section. The end wall of the wave guide or of the cavity (12) is in a plane parallel to the plane that contains the radiating elements (3) of antenna (1) and their feed lines (4).

Abstract: The antenna constituted by a plurality of identical parallel and symmetrical linear sub-networks (a7, a6, . . . a1, a'1, a'2, . . . , a'7). The centres of symmetry (b7, b.notident.b, . . . , b1, b'1, b'2 . . . , b'7) of the sub-networks (a7 to a'7) are aligned on a line (c) perpendicular to their diameter and are fed in phase. Each sub-network is constituted by a plurality of radiating elements in even numbers disposed at regular intervals and which radiate from fields displaced from 180.degree. from one radiating element to the following. The pitch of the sub-network is approximately equal to a wave-length guided on the substrate of the printed circuit. Each radiating element is a conducting square surface the side of which is approximately equal to half the guided wavelength with one corner connected galvanically to the feed line. The direction of the surfaces change from one element to the following element.