scholarly journals Multi-Verse Optimization algorithm for the Optimal Synthesis of Phase-only reconfigurable linear array of mutually coupled parallel half-wavelength dipole antennas placed at finite distances from the ground plane

2020 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
Jamunaa Doraiswamy ◽  
Gautam Kumar Mahanti ◽  
Feras Nadhim Hasoon
Keyword(s):  
Optimization Algorithm ◽  
Linear Array ◽  
Ground Plane ◽  
Optimal Synthesis ◽  
Dipole Antennas ◽  
Half Wavelength

scholarly journals QPSO versus BSA for Failure Correction of Linear Array of Mutually Coupled Parallel Dipole Antennas with Fixed Side Lobe Level and VSWR

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
R. Muralidharan ◽  
Vallavaraj Athinarayanan ◽  
G. K. Mahanti ◽  
Ananya Mahanti
Keyword(s):  
Antenna Arrays ◽  
Processing Time ◽  
Linear Array ◽  
Side Lobe ◽  
Side Lobe Level ◽  
Dipole Antennas ◽  
Statistical Parameters ◽  
Half Wavelength ◽  
Parameter Values ◽  
Linear Antenna Arrays

Evolutionary algorithms play an important role in synthesizing linear array antenna. In this paper, the authors have compared quantum particle swarm optimization (QPSO) and backtracking search algorithms (BSA) in failure correction of linear antenna arrays constructed using half wavelength uniformly spaced dipoles. The QPSO algorithm is a combination of classical PSO and quantum mechanics principles to enhance the performance of PSO and BSA is considered as a modernized PSO using historical populations. These two algorithms are applied to obtain the voltage excitations of the nondefective elements in the failed antenna array such that the necessary objectives, namely, the minimization of parameters like side lobe level (SLL) and voltage standing wave ratio (VSWR), are achieved leading to their values matching closely the desired parameter values. The results of both algorithms are compared in terms of parameters used in the objective function along their statistical parameters. Moreover, in order to reduce the processing time, inverse fast Fourier transform (IFFT) is used to obtain the array factor. In this paper, an example is presented for the application of the above two algorithms for a linear array of 30 parallel half wavelength dipole antennas failed with 4 elements and they clearly show the effectiveness of both the QPSO and BSA algorithms in terms of optimized parameters, statistical values, and processing time.

scholarly journals Requisite design area on the ground plane of U-shaped folded dipole antennas

2013 ◽  
Vol 2 (8) ◽  
pp. 365-371 ◽  
Author(s):  
Tuan Hung Nguyen ◽  
Hisashi Morishita ◽  
Yoshio Koyanagi ◽  
Kazuhiro Izui ◽  
Shinji Nishiwaki
Keyword(s):  
Ground Plane ◽  
Dipole Antennas ◽  
Folded Dipole

scholarly journals Three-Dimensional Imaging of Terahertz Circular SAR with Sparse Linear Array

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2477 ◽  
Author(s):  
Jubo Hao ◽  
Jin Li ◽  
Yiming Pi
Keyword(s):  
3D Imaging ◽  
Linear Array ◽  
Ground Plane ◽  
Three Dimensional ◽  
Terahertz Waves ◽  
Recovery Method ◽  
Imaging Algorithm ◽  
Imaging Geometry ◽  
Imaging Results ◽  
Sparse Linear Array

Due to the non-contact detection ability of radar and the harmlessness of terahertz waves to the human body, three-dimensional (3D) imaging using terahertz synthetic aperture radar (SAR) is an efficient method of security detection in public areas. To achieve high-resolution and all aspect imaging, circular trajectory movement of radar and linear sensor array along the height direction were used in this study. However, the short wavelength of terahertz waves makes it practically impossible for the hardware to satisfy the half-wavelength spacing condition to avoid grating lobes. To solve this problem, a sparse linear array model based on the equivalent phase center principle was established. With the designed imaging geometry and corresponding echo signal model, a 3D imaging algorithm was derived. Firstly, the phase-preserving algorithm was adopted to obtain the 2D image of the ground plane for each sensor. Secondly, the sparse recovery method was applied to accomplish the scattering coefficient reconstruction along the height direction. After reconstruction of all the range-azimuth cells was accomplished, the final 3D image was obtained. Numerical simulations and experiments using terahertz radar were performed. The imaging results verify the effectiveness of the 3D imaging algorithm for the proposed model and validate the feasibility of terahertz radar applied in security detection.

scholarly journals A Dual-Wideband Double-Layer Magnetoelectric Dipole Antenna with a Modified Horned Reflector for 2G/3G/LTE Applications

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Botao Feng ◽  
Weijun Hong ◽  
Shufang Li ◽  
Wenxing An ◽  
Sixing Yin
Keyword(s):  
Double Layer ◽  
Frequency Band ◽  
Lower Layer ◽  
Low Cost ◽  
Impedance Matching ◽  
Ground Plane ◽  
Dipole Antenna ◽  
Dipole Antennas ◽  
Dipole Structure ◽  
Feeding Structure

A novel dual-wideband double-layer magnetoelectric dipole unidirectional antenna with a modified horned reflector for 2G/3G/LTE applications is proposed. Firstly, a double-layer electric dipole structure is presented to provide a dualwideband, whose folded lower layer mainly serves the lower frequency band while the inclined upper layer works for the upper frequency band. In addition, to reduce the size of the antenna and improve impedance matching, a new feeding structure designed with inverted U-shaped and tapered line is introduced. Finally, a modified horn-shaped reflector, instead of a ground plane, is employed to achieve stable and high gains. The antenna prototype can achieve a bandwidth of 24.4% (790 MHz–1010 MHz) with a stable gain of 7.2 ± 0.6 dBi for the lower band, and a bandwidth of 67.3% (1.38 GHz–2.78 GHz) with a gain of 7.5 ± 0.8 dBi for the upper band covering all the frequency bands for 2G/3G/LTE systems. To the best of our knowledge, it is the first double-layer magnetoelectric dipole antenna proposed. Compared with the existing ME dipole antennas, the proposed antenna, which is completely made of copper, can be easily fabricated at low cost and thus is practicable for 2G/3G/LTE applications.

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