CIRCULARLY POLARIZED WAVE GENERATING SECTION OF PRIMARY RADIATOR FOR SATELLITE BROADCAST RECEPTION ANTENNA

摘要

PURPOSE:To ensure the prescribed characteristic without troublesome adjustment or mounting, to reduce the cost of the primary radiator and to attain the mass-production by constituting a couple of flat faces and a couple of concentric circular-arc faces forming an inner circumfer ential face of a circularly polarized wave generating section so as to satisfy a specific condi tion. CONSTITUTION:An inner circumferential face 12 and an outer circumferential face 13 of a circularly polarized wave generating section 11 are tapered along the axial direction of the circularly polarized wave generating section 11. The inner circumferential face 12 is formed by a couple of flat faces 14, 15 opposed to each other and a couple of concentric circular-arc faces 16, 17 over one end and the other end of the flat faces 14, 16. Let two axes orthogonal to each other passing through the center of the cross section of the circularly polarized wave generating section 11 be Ex, Ey respectively, a couple of the flat faces 14, 15 have a tilt of 45 deg. with respect to the orthogonal two axes Ex, Ey. Furthermore, let the length of a major axis at the cross section of the circularly polarized wave generating section 11 be (d), the length of a minor axis be (w) and the length of the circularly polarized wave generating section 11 be l, the dimensions d, w, l are selected respectively so that a phase difference delta between the electric field wave propagating along the major axis and the electric field wave propagating along the minor axis is 90 deg. at an output terminal of the primary radiator.