Polynomial endfire arrays

A nonsidelobe unidirectional endfire array (NUEA) is described. As is well known, there are two kinds of such an array, a 2-elemeat uniform array and a binomial array. The array spacing is usually restricted to , but there is no need to only restrict to such a spacing for NUEA. From a general formula of a uniform endfire array of elements, the unidirectional condition and the nonsidelobe unidirectional condition are obtained. For the uniform NUEA, the array spacing is ; and this array is extended to a polynomial array, of which the array spacing is similarly . These array patterns are monotonically decreasing with a zenithal angle refering to the forward axis.