Dual-polarization wide-band interleaved spiral antenna array

International audienceA new way to design dual polarization wideband spiral antenna array is presented. The proposed technique consists of two interleaved arrays, one for each polarization. The position of every spiral antenna is optimized through a genetic algorithm so that each array is nearly the size of the platform while having low sidelobes. Both resulting arrays have the same properties and are steerable. This method also helps to increase the bandwidth. A 200-elements spiral array (spiral of width 0.25m) with dual polarization is shown, its beam can be steered ±30°, over more than two octaves (2.36:1). The physical rejection of the sidelobes (i.e. without weighting) is about -10 dB. The planar extension is also introduced