Array Pattern Synthesis of Multiband Hexagonal Fractal Antenna Array for Reduced Sidelobe and Deep Null Control using Modified Invasive Weed Optimization Algorithm

Abstract

Design of antenna arrays involving fractal concepts have resulted in the evolution of new fractal antenna array geometries that exhibit multiband characteristics. In this paper array pattern synthesis of hexagonal fractal antenna array (HFAA) is proposed for imposing symmetric nulls in the interference directions while maintaining a reduced side lobe level (SLL) using a modified invasive weed optimization algorithm (MIWO). The desired characteristics are obtained by optimizing the current amplitude coefficients of HFAA. Further multiband characteristics of the fractal array are investigated. The results indicate the improved performance of MIWO when compared to conventional invasive weed optimization algorithm (IWO) in achieving the desired radiation characteristics. Also optimized HFAA demonstrates multiband behavior in achieving similar radiation characteristics.