Abstract: A first disk having radiating elements formed thereon, a second disk having radiating elements formed thereon and overlying the first disk, an electromagnetic energy reflecting disk overlying the second disk and having a first plurality of parallel slots aligned with some of the radiating elements and a second plurality of parallel slots, perpendicular to the first slots, aligned with the remainder of the radiating elements, a nonconducting, spacing layer overlying the reflecting disk and a partially reflecting disk overlying the spacing layer so that the radiating elements form slot sources in the reflecting disk with part of the energy from the slot sources passing through the partially reflecting disk and part being reflected back to the total reflecting disk to form a dual polarized image element antenna array. A second embodiment illustrates different energy radiators.

Abstract: An image element antenna array comprised of slot radiating elements is used for the antenna system for a monopulse tracking system. The image element antenna includes the radiating source disposed between two parallel reflecting planes, one of which is a total reflector and the other a partially reflecting and partially transmitting reflector. The employment of a partially reflecting plane allows for minimizing the number of radiating elements comprising a given antenna array while providing substantially the same gain and pattern activity. The antenna system may be mounted in a missile or the like for transmitting and receiving monopulse energy for steering the missile. The reduced number of radiating elements required reduces the feed network complexity and number with an attended increase in aperture efficiency.