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This paper presents a time modulated far-field radiation pattern synthesis of a compact circular antenna array (CAA) by employing a stochastic optimization technique known as grey wolf optimization...

This paper presents an efficient method to improve the far-field radiation pattern of concentric circular antenna array (CCAA) design using two stochastic optimization algorithms known as social sp...

In this paper, high port isolation in dual feed orthogonally polarized square patch antenna array is achieved by the use of Defected Ground Structure (DGS). A simple rectangular-headed cross DGS is...

This work is concerned with the methodology for improvement of the radiation pattern performance and eliminating the effect of unwanted interference of symmetric time modulated linear antenna array...

This article proposes an area optimized design approach for two different analogue VLSI circuits: current mirror load based CMOS differential amplifier circuit and CMOS two-stage operationa...

This paper describes the synthesis of the radiation characteristics of linear antenna arrays of dipole elements using a nature inspired algorithm called flower pollination algorithm (FPA), ...

In an antenna array due to large number of elements, there is always a possibility of failure of one or more elements in the array system, which results in increased SLL with distorted radi...

In this paper, optimal design of single-ring and multi-ring circular array, hexagonal array, and elliptical array of isotropic antenna has been carried out using Simplex Particle Swarm Opti...

This paper describes the practical implementation of time-modulated linear dipole antenna arrays (TMLDAAs) using EM simulator. Cat swarm optimization (CSO) algorithm is applied to improve the null performance of TMLDAAs by radio frequency switch. The nulls at the particular positions of the direction of arrival of a TMLDAA can be reduced effectively by the proper optimization of current excitation weights and an effective design of switch-on time intervals of each element. CSO gives the optimized value of the current excitation weights of the radiation pattern. The optimized results obtained by CSO algorithm using MATLAB simulation are practically implemented and are designed through computer simulation technology–microwave studio simulation software for half-wave dipole antenna arrays. The dipole antenna is designed to operate at a resonant frequency of 2 GHz. The antenna exhibits a frequency band from 1.8331 to 2.1285 GHz, which is applicable for wireless applications.

In this paper, memetic flower pollination algorithm (MFPA) is proposed for solving the optimal synthesis of time-modulated half symmetric circular antenna array (TMHSCAA) and time-modulated asymmet...

In this paper, the beam steerable isotropic Linear Antenna Array is designed for reducing the side lobe level using evolutionary optimization technique. The optimization techniques particle swarm optimization (PSO) and Novel PSO are used to reduce the side lobe level (SLL) as well as to steer the main beam in specific direction. In this design of steerable Linear arrays, the amplitude excitations are optimized. Obtained results show that the maximum peak of SLL of the resultant patterns is as per requirement. This paper presents a good performance in the array factor response and suppressed SLL for different numbers of elements and different values of the steering angle of direction of the main beam with evolutionary optimization.

In this paper, a nine-ring time-modulated concentric circular antenna array (TMCCAA) with isotropic elements has been analyzed based on an evolutionary optimization algorithm called particle swarm optimization (PSO) with Aging Leader and Challenger (ALC-PSO) for the reduction of side lobe level (SLL) and improvement in the directivity. Some other population-based evolutionary algorithms like real-coded genetic algorithm, PSO, and differential evolution (DE) have also been applied for the sake of comparative performance study of the same optimal designs. The comparative case studies as Case-1 and Case-2 are made with three control parameters like inter-element spacing in rings, inter-ring radii, and the switching “ON” times of rings with the help of same algorithms. ALC-PSO performs the dual task of improvement of directivity values as well as minimization of SLL of TMCCAA. Experimental results show a considerable SLL reduction with respect to the uniform case. Again, the results show Case-2 outperforms Ca...

This paper proposes a novel hybrid optimisation algorithm which combines the recently proposed evolutionary algorithm Backtracking Search Algorithm (BSA) with another widely accepted evolutionary algorithm, namely, Differential Evolution (DE). The proposed algorithm called BSA-DE is employed for the optimal designs of two commonly used analogue circuits, namely Complementary Metal Oxide Semiconductor (CMOS) differential amplifier circuit with current mirror load and CMOS two-stage operational amplifier (op-amp) circuit. BSA has a simple structure that is effective, fast and capable of solving multimodal problems. DE is a stochastic, population-based heuristic approach, having the capability to solve global optimisation problems. In this paper, the transistors’ sizes are optimised using the proposed BSA-DE to minimise the areas occupied by the circuits and to improve the performances of the circuits. The simulation results justify the superiority of BSA-DE in global convergence properties and fine tuning a...

In this paper the authors propose the optimal radiation pattern synthesis of time modulated linear isotropic antenna array with improved directivity and maximum reduction of side lobe level (SLL) and minimum side band levels (SBL) at its harmonics based on evolutionary algorithms applied individually. Evolutionary algorithms are real coded genetic algorithm (RGA), particle swarm optimisation (PSO), novel particle swarm optimisation (NPSO), and the fourth dimension parameter as time. The same array radiates at various harmonic frequencies. The first two harmonic frequencies have been considered in this work. The objective function judiciously chosen enables comparative performance evaluation of the case studies. The numerical results show Case-4 outperforms Case-1, Case-2, and Case-3 with respect to better side lobe level and more improved directivity. Again, the performance of NPSOWM is the best among RGA, PSO, and NPSO for all the case studies. The numerical results also show power radiated by any harmon...

In this paper, swarm-based algorithms craziness particle swarm optimization with wavelet mutation (CRPSOWM) have been applied for the optimal design of hyper beamforming of linear antenna array. The conventional gradient based optimization techniques are not efficient and get trapped on local optima for such multimodal highly non-linear constrained hyper beamforming optimization problem. Thus, the above evolutionary technique has been adopted. CRPSOWM incorporates a new definition of swarm updating with the help of wavelet theory. Wavelet mutation enhances the CRPSO to explore the solution space more effectively compared to the other optimization methods as reported in firefly algorithm (FFA). Thus CRPSOWM is apparently free from getting trapped at local optima and premature convergence. The simulation results show CRPSOWM outperforms FFA by achieving much greater reduction in side lobe level, improved directivity and much more improved first null beam width keeping the same value of hyper beam ex...

This paper proposes an algorithm called cat swarm optimization (CSO) for the optimal design of non-uniform single-ring circular antenna array (CAA) and non-uniform three-ring concentric circular antenna array (CCAA). The algorithm is used to determine an optimum set of current excitation weights and antenna inter-element separations for CAA of 8, 10 and 12 elements and optimal current excitation weights for CCAA, respectively, which provide radiation pattern with maximum reduction of side lobe level (SLL). Two 3-ring CCAAs, one having the set of 4-, 6-, 8-, elements and the other having 8-, 10-, 12- elements, with and without centre element are considered. Simulation results show a considerable improvement of SLL and some restricted improvement of 3-dB beamwidth with respect to the corresponding uniform cases of both the types of antenna array and the corresponding results of some recent literature reported in this paper.