PURPOSE: To simplify a feeding system, and also to improve an elliptical polarization rate extending over a wide angle range in the vertical surface, by constituting a conical beam antenna for a circular polarized wave by use of a semispherical radial line having slots having the shapes formed by 9 and 9' etc. shown in figure.
CONSTITUTION: Semispherical metallic plates 10, 10' which are different in the radius in the radius and are opposed to each other, and a radial line having a coaxial line 11 for feeding to its center are used for this antenna, and it is formed by providing a pair of slots having the shape formed by 9 and 9' in figure on the outside metallic plate 10, and connecting a matching load 12 to the end of the line. The pair of slots having the shape formed by 9, 9' have the center of the slot on the same longitude, an interval in the longitude direction is set so that the slot 9' has a 90° phase difference against the slop 9, and from the viewpoint of space, too, they are placed at an angle against the longitude so as to have an angle difference of 90°, viewing from the beam direction. In this way, the influenced by the same slot as the longitude direction and the latitude direction is negated, and the elliptical polarization rate is improved.
ITANAMI TAKAO
SHIMIZU TADASHI
GOTOU NAOHISA
