Maximisation of directive gain for circular and elliptical arrays

The paper begins with a general formulation of the gain-optimisation procedure for an array with an arbitrary geometrical configuration. The formulation is then specialised to apply to a planar array. In particular, extensive computed data for the maximum obtainable directive gain of circular and elliptical arrays are presented and compared with those with a uniform amplitude and cophasal excitation. For small element separations, a supergain situation results under optimum-gain conditions. A main-beam radiation efficiency is defined, which serves as an additional performance index. In a supergain situation, a proper design represents a suitable compromise between the directive gain and the main-beam radiation efficiency.