God's Sunflower Array: An Improved Circular Array with better Maximum Sidelobe Level and First Null Beam Width Performance

Background & Objective: This paper presents an optimized thinning process (based on density tapering) applied to different circular arrays (CAs) such as circular ring array (CRA), circular concentric array (CCA), circular planar array (CPA) and God's sunflower array (GSFLA). Here, all possible circular arrays are simulated in one platform for better comparison amongst themselves. Methods: The optimization process we have adopted here are particle swarm optimization (PSO) and cuckoo search (CS) optimization techniques. The performance parameters such as maximum sidelobe level (MSLL) and first null beam width (FNBW) of uniformly excited CAs are compared with optimized non-uniformly excited CAs and optimized thinned CAs. Here, the optimized density tapering thinning process provides much reduced MSLL and improved FNBW. Results and Conclusion: The simulation results of different thinned CAs exhibit array taper efficiency in the range of 46% - 61%. This further helps in increasing the overall system capacity keeping gain constant for both thinned and non-thinned CAs. The proposed optimized thinned GSFLA outperforms the other arrays in terms of FNBW and MSLL (~ -35 dB).