Sidelobe level reduction in wide-angle scanning array system using pattern-reconfigurable antennas

A technique aimed at peak sidelobe level (SLL) reduction for wide-angle scanning arrays is presented in this work, based on the use of a newly designed pattern-reconfigurable antenna (PRA). The proposed antenna consists of a monopole antenna and two parasitic strips, where each strip can be reconfigured into either a reflector or a director via PIN diode switches, leading to the beam deflection. A 2.45 GHz PRA was implemented and the measured results demonstrate three reconfigurable patterns, radiating toward two end-fire and one broadside directions, respectively. When this PRA is used in a 1×4 linear array, the SLL is −7.5 dB at end-fire directions and −11.8 dB at broadside. The SLL at end-fire is 7.4 dB enhancement compared to the linear array with the conventional monopole. The design principle was discussed and a Butler-matrix-fed linear array with four PRAs was implemented for demonstration.