Nonuniformly spaced slot array antenna with low sidelobe pattern

A numerical design method for a waveguide slot array antenna is proposed, by which the array, which has a low sidelobe pattern, is numerically designed. The slots are resonant, and the sources with cophasal excitations and desired amplitudes are designed by adjusting the space between the adjacent slots. It is shown theoretically that the desired low sidelobe pattern can be obtained by this method. Next, another design procedure is proposed to obtain the impedance matching at the feed point. This is a forward design from the feed point, and the slots are designed in an opposite sequence to the conventional one, it is also shown theoretically that the desired pattern is obtained.