The heuristic analysis of the problem shows that it can be solved on the following premises:
| — | The array is based on a periodic structure with its inputs interacting before radiation goes to a free space. |
| — | The field pattern in the cross-section of the structure in case of uniform excitation with linear phase progression is close to the field pattern of a plane wave moving away from the array aperture. |
| — | The wave propagation coefficient inside the structure is close to the propagation coefficient in a free space. |
| — | The structure period must not be greater than half the operating wavelength. |
