Logarithmically periodic antenna arrays

Previous research on logarithmically periodic structures has provided frequency independent antennas with gains comparable to that of an aperture of one square wavelength. The purpose of this research has been to study frequency independent methods of arraying logarithmically periodic antennas so as to achieve higher gain. The theory and design procedure for an array of endfire log periodic elements is described. Design data for the element unit patterns and phase centers is presented. Experimental as well as theoretical array patterns are given. Gains of the order of 15 db over an isotropic radiator have been achieved and it is felt that up to 20 db gain is feasible. An element which will be useful for an array of broadside elements is also described.