In this paper, an efficient method to obtain the elements current distribution for a non uniformly spaced array is presented. For a given far field pattern, after sampling the array factor the proposed method uses the least mean square error technique to solve the system ofequations rather than solving the previously published Legendre function method. It's shown that the average side lob level obtained by this proposed method is some 5 dB lower in comparison with the existing Legendre function method ofsolution. Ifthe Legendre function method published in the literature is to be used to solve for the current distribution, in the final part ofthis paper, a criteria on how to choose suitable vectors that would result in a 3 dB lower side lobe level performance will be provided.
2. Harrington, R. F., "Sidelobe reduction by nonuniform element spacing," IEEE Trans. Antennas Propagat., Vol. 9, 187, 1961.
3. Ishimaru, A., "Theory ofunequally-spaced arrays," IEEE Trans. Antennas & Propagat., Vol. 10, 691-702, 1962.
4. Skolnik, M. I., G. Nemhauser, and J. W. Sherman III, "Dynamic programming applied to unequally spaced arrays," IEEE Trans. Antennas & Propagat., Vol. 12, 35-43, 1964.
5. Mailloux, R. J. and E. Cohen, "Statistically thinned arrays with quantized element weights," IEEE Trans. Antennas & Propagat., Vol. 39, 436-447, 1991.
6. Haupt, R. L., "Thinned arrays using genetic algorithms," IEEE Trans. Antennas & Propagat., Vol. 42, 993-999, 1994.
7. Mahanti, G. K., N. Pathak, and P. Mahanti, "Synthesis of thinned linear antenna arrays with fixed side lobe level using real-coded genetic algorithm," Progress In Electromagnetics Research, Vol. 75, 319-328, 2007.
8. Kumar, B. P. and G. R. Branner, "Design ofunequally spaced arrays for performance improvement," IEEE Trans. Antennas & Propagat., Vol. 47, No. 3, 1999.
9. Zhou, Y. P. and M. A. Ingram, "Pattern synthesis for arbitrary arrays using an adaptive array method," IEEE Trans. Antennas & Propagat., Vol. 47, No. 5, 1999.
10. Olen, C. A. and R. T. Compton Jr., "A numerical pattern synthesis algorithm for arrays," IEEE Trans. Antennas & Propagat., Vol. 38, 1666-1676, 1990.
11. Guney, K. and M. Onay, "Amplitude-only pattern nulling of linear antenna arrays with the use ofBees algorithm," Progress In Electromagnetics Research, Vol. 70, 21-36, 2007.
12. Mouhamadou, M., P. Vaudon, and M. Rammal, "Smart antenna array patterns synthesis null steering and multi user beam forming by phase control," Progress In Electromagnetics Research, Vol. 60, 95-106, 2006.