Production of minimum radiation over a given range of angles for a directional aerial array.

In some applications it may be desirable to construct an aerial array to radiate minimum energy in a certain angular sector whilst providing high gain in the required direction. In this paper the far field expression for the radiation pattern of a broadside array is reduced to a function of several variables of the inter-element spacing. The element positions are then optimized to correspond to minimum radiation over a specified sector. Experimental results have been obtained in accordance with the theoretical predictions, but difficulty was experienced in achieving small signal measurement near the theoretical minima in the laboratory.
The purpose of the present paper is to show that a similar result is possible in the case of a non-uniformly spaced element array uniformly excited. [ABSTRACT FROM AUTHOR]