A Novel Tapered Beamforming Window for Uniform Concentric Circular Arrays

Abstract

A new tapering window is proposed for the uniform concentric circular arrays (UCCA) in order to reduce the sidelobe level at lower cost of wider beams and more practical feasibility and stability. The window has decaying exponential variation with the number of rings depending on the exponent used. The optimum value of the exponent is found to be between 0.4 and 0.5 for noncentral element UCCA and between 0.2 and 0.3 for central element UCCA. The sidelobe level can be reduced to about 26 dB and this level occurs when the number of rings equals the number of elements of the innermost ring at the optimum values of the exponent.