The suppression of the side-lobe level (SLL) of antenna arrays is a significant factor that can enhance the reliability and validity of a communication system. Recently, metaheuristic algorithms have been widely implemented in the design of antenna arrays, in order to find the optimal minimization for the side-lobe level of the array's radiation pattern. In this paper, we propose a new hybrid algorithm that combines the characteristics of two stochastic algorithms, Antlion Optimization (ALO) algorithm and Grasshopper Optimization Algorithm (GOA). ALO, which is an evolutionary algorithm, is robust in exploitation and has been effectively used in many articles in the literature. GOA has strong capability of exploration all over the search space due to the swarm nature of the algorithm, which has been proven in several articles in the literature. Therefore, combining these characteristics and overcoming the drawbacks of ALO and GOA are the main motivation behind hybridizing ALO and GOA in one hybrid algorithm. Simulation results show that the proposed hybrid algorithm has a good performance in the radiation pattern optimization of circular antenna array (CAA) and fast convergence rate compared with other strong optimization algorithms, which prove the efficiency, robustness, and stability of the hybrid algorithm.

Abstract-In this paper, different topologies of dual-frequency modified 3-way Bagley polygon power dividers are designed and analyzed. Equal split power division is achieved at arbitrary design frequencies. In the first structure, two-section transmission line transformer is used to realize the dual-frequency operation. In the second and third structures, dual-frequency T-shaped and π-shaped matching networks are used. For the sake of simplicity, closed form design equations are presented for each matching network. To validate the design procedure, three examples are designed, simulated, and fabricated. The three matching networks are explored through these three examples. The design frequencies are chosen to be 0.5 GHz and 1 GHz.