A unit cell based low side lobe level design for series-fed array antennas

In this paper a simple design strategy for low side lobe level (SLL) series-fed arrays is presented. In the common approach the width of each patch of the array is varied to shape the aperture distribution. The proposed design is based on simple transmission line (TL) model of a low impedance line (the patch) and a high impedance line forming a unit cell. The overall resonances and voltage distribution are analyzed through a periodic boundary technique. A global resonance mode is identified with a cosine voltage distribution at the unit cell terminals (patch edges). This mode is exploited in a series feed array to obtain a smooth cosine amplitude aperture distribution along with the ideal SLL of -23 dB. This method is ideally suited for a simple and straight forward EM optimization.