Development a New Algorithm to Reduce SLL of an Equally Spaced Linear Array

Abstract

Most of Equally Spaced Linear Arrays (ESLA) do not provide desirable Side Lobe Levels (SLL) and thus are less preferable in applications requiring minor SLLs. This paper presents a new algorithm to reduce SLL without any significant penalty on Half Power Beamwidth (HPBW) of the linear arrays. A periodic function is defined, which is equal to the main lobe direction and is zero along other directions; the values of this periodic function is equal to values of the SLL in original array. The excitation coefficients of this periodic function are obtained using commonly methods of pattern synthesizing. By subtracting the original array factor from the periodic function, SLL of the final array is reduced. The numerical results show that by this method, the HPBW is approximately unchanged, while the final array provides the smaller First Null Beamwidth (FNBW) compared to that of the original array.