Artificial Bee Colony Algorithm to Reduce the Side Lobe Level of Uniformly Excited Linear Antenna Arrays through Optimized Element Spacing

In this work, the effectiveness of a relatively newly developed optimization algorithm, artificial bee colony (ABC) algorithm has been employed to synthesize uniformly excited, non-uniformly spaced, symmetrical linear arrays. ABC is used to reduce the side lobe level (SLL) of uniformly excited linear antenna arrays by taking the element spacing as the optimization parameters. The effectiveness of the proposed approach is demonstrated by considering a linear antenna array of 32 elements. The array of isotropic elements is synthesized for the different search space of the element spacing and a typical variation of the SLL with different limiting values of the maximum element spacing is presented. It is observed that, for the isotropic element array when the search range of the normalized element spacing's relative to the operating wavelength is (0.5, 1), the maximum reduction of side lobe level (-21.22 dB) is obtained. At the end the array with half-wavelength dipole is considered and with the search range of the element spacing's, (0.5, 1), SLL is reduced to -22.99 dB.