Arrays of Point Sources

Arranging the elements in an aperture is the critical first step in the array design process. Point sources replace real antenna elements in order to determine the element spacing, lattice, aperture shape, and number of elements that meet array performance requirements. The amplitude and phase of the electromagnetic field radiated by an isotropic point source are constant at a set instant in time and distance from the source. Aliasing occurs when the array takes less than 2 samples of the signal per period. Spatial aliasing produces large pattern lobes that steal gain from the main beam and point in directions other than the desired direction. Elements in a subarray are combined to form one signal. The Bayliss amplitude taper produces low sidelobes for different patterns. The normalized desired amplitude taper serves as a probability density function for a uniform array that is to be thinned.