scholarly journals Conformal Array Pattern Synthesis Using a Hybrid WARP/2LB-MOPSO Algorithm

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Roghieh Karimzadeh Baee ◽  
Keyvan Forooraghi ◽  
Somayyeh Chamaani
Keyword(s):  
Degrees Of Freedom ◽  
Mutual Coupling ◽  
Side Lobe ◽  
Penalty Functions ◽  
Main Beam ◽  
Side Lobe Level ◽  
Initial Population ◽  
Pattern Synthesis ◽  
Conformal Array ◽  
Multiobjective Particle Swarm Optimization

This paper addresses conformal array synthesis as a constrained multiobjective optimization problem. Simultaneous reduction of side lobe level (SLL) and cross-polarization (XPL) level is aimed with a constraint on main beam direction. A hybrid of weighted alternating reverse projection (WARP) and two local best multiobjective particle swarm optimization (2LB-MOPSO) is proposed to optimize the pattern. First, the WARP method finds a moderate and feasible solution. Second, 2LB-MOPSO begins with an initial population including the solution of WARP and penalty functions for constraint handling. Involving WARP result in the initial population of 2LB-MOPSO leads to higher convergence rate, avoiding local extermum traps and less sensitivity to penalty functions. Compared to WARP method which stagnates rapidly, the proposed hybrid method gives better SLL and XPL after adequate iterations. In addition, as 2LB-MOPSO offers a set of optimum solutions (Pareto front) instead of a single solution, this method provides more degrees of freedom in selection of proper practical arrays. Finally, to examine the mutual coupling consideration in array design, the same procedure was applied ignoring the mutual coupling between elements. The results show that the SLL and XPL strongly depend on mutual coupling.

Radiation Pattern Synthesis and Mutual Coupling Compensation in Spherical Conformal Array Antennas

2021 ◽  
Vol 36 (6) ◽  
pp. 707-717
Author(s):  
Taimur Khan ◽  
Muhammad Khattak ◽  
Adnan Tariq
Keyword(s):  
Radiation Pattern ◽  
Mutual Coupling ◽  
Surface Deformation ◽  
Spherical Shape ◽  
Least Square ◽  
Spatial Distance ◽  
Main Beam ◽  
Antenna Gain ◽  
Pattern Synthesis ◽  
Conformal Array

This paper presents a novel technique based on Hybrid Spatial Distance Reduction Algorithm (HSDRA), to compensate the effects of deformity and mutual coupling occurred due to surface change in conformal arrays. This antenna surface deformation shifts the position of null points and loss of the main beam resulting in reduced antenna gain along with substantial undesirable effects on the antenna performance. The proposed algorithm, which cumulatively incorporates the Linearly Constraint Least Square Optimization (LCLSO) and Quadratically Constraint Least Square Optimization (QCLSO) techniques, is formulated to minimize/reduce the absolute distance between the actual (simulated/measured) radiation pattern and the desired radiation pattern while keeping the direction of main beam and nulls position under control. In particular, a 4x4 conformal microstrip phased array from planar surface is deformed to prescribe spherical-shape surface with various radii of curvature, is validated. For the enhancement of Gain of the conformal array antenna, Gain Maximization Algorithm is also proposed, the simulated results of which is compared to the traditional Phase compensation technique and unconstraint least squares optimization. The analytical results for both planar and spherical deformed configurations are first evaluated in MATLAB and then validated through Computer Simulation Technology (CST).

Pattern Synthesis of Circular Array Antenna by Improved Genetic Algorithm

2012 ◽  
Vol 236-237 ◽  
pp. 896-900
Author(s):  
Gong Wei Ren ◽  
Cheng Hua Zhou
Keyword(s):  
Genetic Algorithm ◽  
Side Lobe ◽  
Array Antenna ◽  
Main Beam ◽  
Side Lobe Level ◽  
Improved Genetic Algorithm ◽  
Pattern Synthesis ◽  
Multi Objective Genetic Algorithm ◽  
Real Coded Genetic Algorithm ◽  
Crossover And Mutation

Propose an application of multi-objective genetic algorithm (GA) for pattern synthesis of circular arrays with equally spaced isotropic elements. Aim at reduce the side-lobe level and deep the null of array antenna patterns, adopt improved real-coded genetic algorithm, which modify the crossover operator and mutation operator compare with standard GA, both the crossover and mutation probability adjustable in accordance with the generation numbers, in the final, the approach for antenna pattern synthesis can suppress interferences by deep the nulls at directions of interfering sources and placing main beam in direction of desired signal by controlling amplitude weights. Numerical results show effectiveness of the procedure proposed.

scholarly journals Design and Analysis of Thinned Array Pattern Reconfigurable Antenna to Enlarge the Scanning Range

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Zhangjing Wang ◽  
Xing Fan ◽  
Haijuan Cui ◽  
Shaoqiu Xiao
Keyword(s):  
Degrees Of Freedom ◽  
Visible Region ◽  
Beam Width ◽  
Side Lobe ◽  
Main Beam ◽  
Side Lobe Level ◽  
Weighted Function ◽  
Thinned Array ◽  
Weighted Factor ◽  
Scanning Range

A novel thinned array with symmetric distribution along the array center is proposed in this paper. The proposed symmetric thinned array is based on the theory of unequally spaced array and the amplitude of each element in the array can be changed by introducing the weighted function. The pattern of the proposed array can be properly adjusted by changing the weighted function and the amplitude of the weighted factor, which obviously releases new degrees of freedom in array design. It has advantages such as low side lobe level (SLL) in the visible region, no grating lobes, and low nearby side lobe level (NSL), which has good potential for wide-angle scanning. Both simulation and experiment have been done; the experiment results show that, by applying this novel symmetric thinned array with pattern reconfigurable quasi-Yagi antenna, the scanning range of the array is −70°~70° inH-plane with SLL almost −10 dB below the maximum of the main beam. The 3 dB beam-width coverage is −86°~86°, which means that the proposed array can realize the entire upper-space beam coverage and restrain the SLL at the same time.

Performance Evaluation of Elliptical-Cylindrical Antenna Array using SaDE Optimized Hyper Beam

2017 ◽  
Vol 7 (1) ◽  
pp. 178 ◽  
Author(s):  
Gebrehiwet Gebrekrstos Lema
Keyword(s):  
Communication Systems ◽  
High Performance ◽  
Optimization Technique ◽  
Analytical Techniques ◽  
Side Lobe ◽  
Optimization Techniques ◽  
Side Lobe Level ◽  
Pattern Synthesis ◽  
Improved Performance ◽  
The Individual

<p>For high performance communication systems, Side Lobe Level (SLL) reduction and improved directivity are the goal of antenna designers. In the recent years, many optimization techniques of antenna design are occupying demanding place over the analytical techniques. Though they have contributed attractive solutions, it is often obvious to select one that meets the particular design need at hand. In this paper, an optimization technique called Self-adaptive Differential Evolution (SaDE) that can be able to learn and behave intelligently along with hyper beam forming is integrated to determine an optimal set of excitation weights in the design of EcAA. Non-uniform excitation weights of the individual array elements of EcAA are performed to obtain reduced SLL, high directivity and flexible radiation pattern. To evaluate the improved performance of the proposed SaDE optimized hyper beam, comparison are done with uniformly excited, SaDE without hyper beam and Genetic Algorithm (GA). In general, the proposed work of pattern synthesis has resulted in much better reduction of SLL and FNBW than both the uniformly excited and thinned EcAA. The results of this study clearly reveal that the SLL highly reduced at a very directive beamwidth.</p>

scholarly journals Design of Non-Uniformly Spaced Circular Arrays of Parasitic Dipoles for Lower Side Lobe Level with Maximum Directivity

2018 ◽  
Vol 7 (1) ◽  
pp. 51-56 ◽  
Author(s):  
H. Patidar ◽  
G. K. Mahanti
Keyword(s):  
Mutual Coupling ◽  
Side Lobe ◽  
Side Lobe Level ◽  
Circular Array ◽  
Method Of Moment ◽  
Lower Side ◽  
New Approach ◽  
Circular Arrays ◽  
Maximum Directivity ◽  
Active Dipole

This paper presents a new approach for circular array of parasitic dipoles composed by one active dipole for reduction of side lobe level with maximum directivity including mutual coupling. The desired goal is obtained by changing the spacing between the parasitic elements and length of the parasitic elements while the position and length of driven element is fixed. In addition to it, reflection coefficient (RC) of the driven element is kept closer to the specified value. Matlab based method of moment code is used to evaluate the performance of circular antenna designs generated by QPSO algorithm. Two examples are presented to show the effectiveness of this proposed approach.  

scholarly journals Optimal Pattern Synthesis of Linear Antenna Array Using Grey Wolf Optimization Algorithm

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Prerna Saxena ◽  
Ashwin Kothari
Keyword(s):  
Antenna Arrays ◽  
Side Lobe ◽  
Optimization Techniques ◽  
Main Beam ◽  
Linear Antenna ◽  
Grey Wolf ◽  
Grey Wolf Optimization ◽  
Pattern Synthesis ◽  
Uniform Array ◽  
Linear Antenna Arrays

The aim of this paper is to introduce the grey wolf optimization (GWO) algorithm to the electromagnetics and antenna community. GWO is a new nature-inspired metaheuristic algorithm inspired by the social hierarchy and hunting behavior of grey wolves. It has potential to exhibit high performance in solving not only unconstrained but also constrained optimization problems. In this work, GWO has been applied to linear antenna arrays for optimal pattern synthesis in the following ways: by optimizing the antenna positions while assuming uniform excitation and by optimizing the antenna current amplitudes while assuming spacing and phase as that of uniform array. GWO is used to achieve an array pattern with minimum side lobe level (SLL) along with null placement in the specified directions. GWO is also applied for the minimization of the first side lobe nearest to the main beam (near side lobe). Various examples are presented that illustrate the application of GWO for linear array optimization and, subsequently, the results are validated by benchmarking with results obtained using other state-of-the-art nature-inspired evolutionary algorithms. The results suggest that optimization of linear antenna arrays using GWO provides considerable enhancements compared to the uniform array and the synthesis obtained from other optimization techniques.

scholarly journals Improving the Performances of Microstrip Antenna Array using Defected Ground Structure

2020 ◽  
Vol 9 (3) ◽  
pp. 1081-1086
Keyword(s):  
Antenna Array ◽  
Power Distribution ◽  
Mutual Coupling ◽  
Impedance Matching ◽  
Side Lobe ◽  
Power Divider ◽  
Side Lobe Level ◽  
Patch Antennas ◽  
Defected Ground Structure ◽  
Ground Structure

In this paper, a two elements antenna array with defective ground structure (DGS) has been designed to achieve significant gain, polarization purity and reduced mutual coupling. A 3 port Wilkinson power divider has been designed at 4.5 GHz frequency to obtain equal power distribution at the output ports. Two Rectangular microstrip patch antennas with DGS at the corners yield improved gain, impedance matching and polarization purity in both E and H plane. The reduction of mutual coupling and side lobe level (SLL) have been achieved by placing the dumbbell shaped DGS bellow the feed line of the power divider. The radiation performances obtained using the fabricated prototype agrees well with that of the simulated one. This array has been designed for C-band application.

scholarly journals Electronically Steered MIMO Patch Antenna with Conformal Feeding for 5 G Applications

2021 ◽  
Author(s):  
monish gupta
Keyword(s):  
Input Signal ◽  
Patch Antenna ◽  
Phase Shifter ◽  
Side Lobe ◽  
Power Divider ◽  
Main Beam ◽  
Beam Forming ◽  
Side Lobe Level ◽  
Mimo Antenna ◽  
Wilkinson Power Divider

Abstract Multiple input multiple output antenna is the key technology which enables the design of 5 G networks. In order to achieve desired beam forming and side lobe reduction capabilities, antennas used in MIMO technology are required to feed with signals having different phase and amplitude. It is possible to achieve variable phase shift and variable attenuation using phase shifter and amplitude limiters. However when these devices are used between source and antenna, they makes the system non planner and non-conformal. This research presents a 16 element, multiple user MIMO Patch antenna with conformal and planner power divider network to achieve electronically steered beam along with desired side lobe level reduction. Wilkinson power divider is used to achieve conformal and planner power divider for MIMO antenna. Desired beam forming capabilities are achieved by controlling the phase of input signal to antennas by controlling the length of microstripline and desired side lobe reduction capabilities are achieved by controlling the amplitude of input signal to antenna by controlling the width of microstrip line used in Wilkinson power divider. This provides an overall planner and conformal structure. In this research same antenna is used is generate two major beams by controlling the phase and amplitude of input signal. The achieved radiation pattern of designed antenna consists of one major beams having gain of 18 dB and located at theta equal to 100 and Phi equal to 1800. When phase of input signal to antennas are changed a major beam having gain of 18 dB and located at theta equal to 100 and Phi equal to 2700 is obtained. The side lobe level less than 13 dB of main beam is achieved using designed antenna. The designed structure is simulated and analyzed using HFSS. Simulated results for the designed MIMO antenna are verified by analyzing the fabricating structure using vector network analyzer and horn antenna.

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