Constant elevation pattern notch design in a rectangular phased array having a triangular lattice

When designing the aperture distribution for a constant elevation pattern notch in a rectangular, planar phased array with a triangular lattice, the designer may be tempted to set the excitation of each element individually, based on sampling a desired continuous distribution at each element´s unique location. It can be shown that for some types of aperture distributions, such as a principal-plane notch on one side of the main beam, this can cause unacceptable lobes to appear away from the principal planes. The resolution to this problem is to first generate the distribution for the elements in one (odd) column, and then directly apply these excitations to the elements in the adjacent (even) column. This has the effect of increasing the periodicity of sidelobe features in k-space, which causes a notch to appear in the sidelobe structure of the grating lobes at the desired location