Performance Evaluation of Concentric Hexagonal Array for Smart Antenna Applications

Many of the antenna array geometries considered so far are linear and circular arrays. In this paper, a different geometrical array, Concentric Hexagonal Array (CHA) is reported for the beamforming of Smart Antenna applications. The advantage of this array over other geometrical configurations is it gives less side lobe level (SLL) and also it achieves pattern symmetry for the non-uniform amplitude excitation. Since the radiation pattern becomes symmetric, and the element’s amplitude carry even symmetry about the array’s center, the computing time and the number of attenuators turn to be halved for the amplitude—only synthesis which in turn reduces the cost of the system. Using the 12-element hexagonal array, a 24-element and 36-element concentric hexagonal array is constructed and their performances are evaluated. The 24-element CHA allows less side lobe level as with 36-element. The performance of 24-element is also analyzed with circular and hexagonal arrays with same elements. Firefly algorithm is used for beamforming and also to obtain the excitation coefficients.