Parabolic antenna with horn feed array

Abstract

A radio frequency antenna having a parabolic reflecting surface and an array of feeds disposed adjacent the focal point of the parabolic reflecting surface, such feeds providing a predetermined amplitude and phase distribution to radio frequency signals passing to such feeds, each one of such feeds passing such energy in the same propagation mode. The energy passing through each one of the feeds is reflected from the reflecting surface and combines at the radiating aperture to provide, in free space, an antenna pattern having relatively low sidelobes over a relatively wide band of frequencies. The array of feeds includes a waveguide section having opposing outer wall portions and a plurality of conductive members disposed between the opposing outer wall portions to provide, with the outer wall portions, a plurality of channels. The conductive members have first ends pivotally connected, at regularly spaced positions, to a pair of orthogonally disposed outer wall portions whereas the spacing between the second ends of the conductive members and the first mentioned pair of outer wall portions establishes the amplitude and phase distribution of the array of feeds. Such channel structure is adapted to provide the desired amplitude and phase distribution and operate with relatively large amounts of power.