Circular antenna array (CAA) is one of the most widely used antenna array designs. This paper addresses the design challenges of the CAA with the non-uniform single ring, which is placed in an X-Y plane with the best sidelobe level (SLL) and improved first null beamwidth (FNBW). It has been solved using differential evolution, craziness-based particle swarm optimization (CRPSO), and novel particle swarm optimization (NPSO) techniques. An optimal combination of feeding current and inter-element spacing provides an array pattern with the best SLL and improved FNBW, as well as some other parameter calculations of the antenna array like maximum directivity, maximum effective aperture, total effective aperture, maximum beam area, total beam area, circumference, and radius of the CAAs using these techniques. There are six designs of CAAs with different antenna elements (i.e., 10-, 12-, 16-, 20-, 36-, and 64-elements) which have been taken into account. Simulations are done in MATLAB. Based on various simulation results, we can analyze the performance of SLL and FNBW with other parameters using NPSO and compare them with different techniques of CAAs, as shown in the numerical analysis and simulation result section.

In this paper, equilibrium optimization algorithm (EOA), which is a novel optimization algorithm, is applied to synthesize symmetrical linear antenna array and non-uniform circular antenna array (CAA). The main purpose of antenna array synthesis is to achieve a radiation pattern with low maximum side lobe level (MSL) and narrow half-power beam width (HPBW) in far-field. The low MSL here is an important parameter to reduce interference from other communication systems operating in the same frequency band. A narrow HPBW is needed to achieve high directionality in antenna radiation patterns. Entering the literature as a novel optimization technique, EOA optimally determined the amplitude and position values of the array elements to obtain a radiation pattern with a low MSL and narrow HPBW. The EOA is inspired by models of the control volume mass balance used to predict equilibrium as well as dynamic states. To demonstrate the flexibility and performance of the proposed algorithm, 10-element, 16-element and 24-element linear arrays and eight-element, 10-element and 12-element CAAs are synthesized. The MSL and HPBW values of radiation pattern obtained with the EOA are very successful compared to the results of other optimization methods in the literature.

This paper presents an efficient approach for the design of a non-uniform single ring circular antenna array (CAA) for the synthesis of the optimal far-field radiation pattern. A recently proposed meta-heuristic-based optimization technique known as ant lion optimization (ALO) is applied in this paper to determine the optimum set of current amplitude excitation weights and the inter-element distance among the array elements to reduce the side lobe level (SLL) and 3-dB beam width considering the mutual coupling effect. The results achieved by employing the ALO algorithm are compared with the uniform radiation pattern and with those of the recently reported literature containing equal sets of elements to prove the superiority of ALO algorithm. Three different design examples of 8, 10, and 12 elements CAA are presented, and their performances are compared to illustrate the capability of the ALO algorithm-based approach over those of the recently reported literature.

Synthesis of non-uniform circular antenna arrays using a hybrid invasive weed optimization is introduced in this paper. The excitation weights and positions of array elements are optimized to reduce the peak side lobe level (PSLL) of the radiation pattern. The method proposed in this paper can effectively constrain the number of the array elements, size of the array, and the angular spacing of the adjacent element simultaneously. The radiation pattern has the constraint of a fixed major lobe beamwidth. Synthesis results of three different circular antenna arrays are given. The results show the effectiveness and feasibility of the proposed synthesis method in non-uniform circular antenna arrays.