On the ideal element pattern in planar phased array antennas

In large multielement planar arrays with a regular lattice, the overwhelming majority of the elements are in practically identical conditions. This allows neglecting the edge effect and considering the array as an infinite periodic structure where all the elements have identical radiation patterns. If the power supplied to the array inputs is completely radiated in the main lobe scanning in a given region, then the array gain is highest possible, and the corresponding element pattern is considered as ideal. The concept of the ideal element pattern is considered in detail where it is exhaustively defined for the cases of the single-beam scanning in the whole real space. The present paper evolves these ideas for the arrays with relatively large spacings guarantying the presence of the main lobe or at least one grating lobe in real space for any control phases, as it usually takes place in practice. It includes the issues of the element pattern contour shape and the level on the contour, which were not considered before. The examples are given for some promising applications, and the features of an array with the conical clement pattern having the non-ideal contour are discussed as well.