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Applied Computational Intelligence and Soft Computing
Volume 2011 (2011), Article ID 692197, 9 pages
http://dx.doi.org/10.1155/2011/692197
Research Article

Null Steering in Failed Antenna Arrays

Department of Electronics and Computer Engineering, Indian Institute of Technology Roorkee, Roorkee 247 667, India

Received 29 December 2010; Revised 21 April 2011; Accepted 16 May 2011

Academic Editor: Miin-Shen Yang

Copyright © 2011 Om Prakash Acharya et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Antenna array pattern nulling is desirable in order to suppress the interfering signals. But in large antenna arrays, there is always a possibility of failure of some elements, which may degrade the radiation pattern with an increase in side lobe level (SLL) and removal of the nulls from desired position. In this paper a correction procedure is introduced based on Particle Swarm Optimization (PSO) which maintains the nulling performance of the failed antenna array. Considering the faulty elements as nonradiating elements, PSO reoptimizes the weights of the remaining radiating elements to reshape the pattern. Simulation results for a Chebyshev array with imposed single, multiple, and broad nulls with failed antenna array are presented.