Analysis of nonuniform excitation and element spacing in sidelobe reduction of wideband U-slot microstrip patch phased array antennas

The sidelobe reduction of a 17-element L-probe-fed U-slot microstrip linear phased array is effected. Results indicate that using nonuniform excitation and inter-element spacing can reduce the sidelobe levels by over -10dB when compared to nonuniform excitation only and by over -7dB when compared with nonuniform inter-element spacing only. This is mainly observed as the array is scanned 60° away from broadside.