Sector nulling in planar irregular sub-arrayed sparse array antennas.

This study concerns wide angular sector (higher order) null synthesis in planar irregular sparse antenna arrays when aperture distributed sub-arrays are used to reduce the computational load. A hybrid optimisation tool has been used to find array element excitations to achieve as low as possible sector nulls for the desired sector width. Performance comparisons have been made for three sub-array configurations based on the obtained numerical results. Various interference jamming scenarios have been considered including single and dual sectors for single-dimensional (θ) (1D) and two-dimensional (θ, ϕ) (2D) nulls. The proposed optimisation scheme has shown to be successful for the synthesis of 1D and 2D sector nulls with depths as low as -100 dB for the given configuration with reduced computational time when compared with the full array. The comparison of achieved null depths for different sub-array sizes and convergence time has also been presented and discussed. [ABSTRACT FROM AUTHOR]