Optimized wideband steerable antenna array using an 8x8 Butler matrix

This paper presents a wideband planar steerable antenna array. The structure is composed of an 8x8 Butler matrix connected to an 8x1 antenna array. It is fabricated on an FR-4 substrate and operates at 3GHz. The disadvantage of the 8x8 Butler matrix is the small bandwidth. Therefore, this paper introduces the development of wideband components to enlarge the bandwidth of the structure resulting in a bandwidth of 1.26GHz. Moreover, the 8x8 Butler matrix to be presented in this work is special in comparison to the existing works in the literature because it permits reusing the 4x4 Butler matrix in the design. This operation is valuable in the industry since it reduces the effort and the cost of the production. The final structure uses wideband and miniaturized components on a single layer substrate which results in an economical, small size and wideband steerable antenna array.