Amplitude‐only pattern nulling of linear antenna arrays with the use of an immune algorithm

This article presents an optimization immune algorithm (opt‐IA) for null steering of linear antenna arrays by controlling only the element amplitudes. Nulling of the pattern is also achieved by controlling the phase‐only and the complex weights (both the amplitude and phase) of the array elements. The opt‐IA is a new evolutionary computing algorithm based on the clonal selection principle of immune system. To show the accuracy and flexibility of the proposed opt‐IA, several examples of Chebyshev array pattern with the imposed single, multiple, and broad nulls are given. It is found that the nulling technique based on opt‐IA is capable of steering the array nulls precisely to the undesired interference directions. © 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008.