This paper presents a modified Genetic Algorithm (GA) technique in which the large phase perturbations are calculated by aggregating small phase increments. The proposed aggregation GA technique overcomes the major drawback of the large solution space required by the classical GA techniques. The proposed method adopts small ranges for increments of the parameters and the optimality is reached via aggregation of the best increments of phases. Consequently, the GA searches in a smaller solution space and finds the solution with reduced number of iterations. Simulation results show the achieved improvement of the proposed technique over the classical GA. The suppressed sectors using phase-only control are accomplished with and without element failures. Problems like imposing symmetrical nulls around the mainbeam and compensation for the failure of center element have been achieved.
2. Steyskal, H., "Simple method for pattern nulling by phase perturbation," IEEE Trans. on Antenna and Propagation, Vol. 31, 163-166, 1983.
3. Vu, T. B., Method of null steering without using phase shifters, IEE Proceedings, Vol. 131, No. 4, 1984.
4. Shore, R., "Nulling at symmetric pattern location with phaseonly weight control," IEEE Trans. on Antenna and Propagation, Vol. 32, No. 5, 530-533, 1984.
5. Mismar, M. J. and T. H. Ismail, "Pattern nulling by iterative phase perturbation," Progress in Electromagnetics Research, Vol. 22, 181-195, 1999.
6. Trastoy, A. and F. Ares, "Phase-only control of antenna sum patterns," Progress in Electromagnetics Research, Vol. 30, 47-57, 2001.
7. Haupt, L. R., "Phase-only adaptive nulling with a genetic algorithm," IEEE Trans. on Antenna and Propagation, Vol. 45, No. 6, 1009-1015, 1997.
8. Yan, K. and Y. Lu, "Sidelobe reduction in array-pattern synthesis using genetic algorithm," IEEE Trans. on Antenna and Propagation, Vol. 45, No. 7, 1117-11122, 1997.
9. Ares-Pena, F., J. Rodriguez-Gonzalez, E. Villanueva-Lopez, and S. Rengarajan, "Genetic algorithms in the design and optimization of antenna array patterns," IEEE Trans. on Antenna and Propagation, Vol. 47, No. 3, 506-510, 1999.
10. Dawoud, M. and M. Nuruzzaman, "Null steering in rectangular planer arrays by amplitude control using genetic algorithms," Int. J. Electronics, Vol. 87, No. 12, 1473-1484, 2000.
11. Michalewicz, Z., Genetic Algorithms+Data Structures=Evolution Programs, 3rd edition, Springer-Verlag, Berlin Heidelberg, 1996.
12. Joines, J. A. and C. R. Houck, On the use of non-stationary penalty functions to solve nonlinear constrained optimization problems with GA's, Proceedings ofthe 1st IEEE Int. Conf. On Evolutionary Computation, Vol. 1, 27-29, 1994.
13. Holland, J. H., Adaptation in the Natural and Artificial Systems, University of Michigan Press, Ann Arbor, 1975.
14. Mismar, M. J. and T. H. Ismail, "Null steering with element failures using partial controlled linear arrays," Electromagnetics, Vol. 23, No. 5, 445-454, 2003.