Switchable end-fire element for three-dimensional array use

Use of interpolation processor coefficients as weights in a particular line array format leads to an end-fire pattern having special properties. A wide, nearly constant gain main beam results which is complemented by a backside region having uniformly low peak sidelobe levels. Changing the polarity of one element reverses the direction of energy flow. Use of these simple line arrays as elements of a planar array permits elimination of the back-screen and offers bidirectional coverage. An overview of the technique is presented along with some design examples.