scholarly journals SIMULATION OF A FLEXIBLE LINEAR GRAPHENE ANTENNA ARRAY ON A PAPER SUBSTRATE

2021 ◽  
Vol 8 ◽  
pp. 307-313
Author(s):  
Alexander G. Cherevko ◽  
Yury V. Morgachev

The article presents an analysis of flexible graphene antenna arrays, which has shown the promise of using a folded dipole antenna as an element of such array. The structure of the flexible folded dipole operating at a frequency of 5,8 GHz on a photo-paper substrate is considered. Simulation yields a gain of 2,53 dBi with a final efficiency of 75% and | S 11| -31,82 dB. The influence of bending on the final shape of the radiation pattern is considered, as well as the value and position of the minimum of the | S 11|. The gain of a linear three-element graphene flexible antenna array based on a folded flexible dipole is 5,78 dBi.

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
E. Saenz ◽  
K. Guven ◽  
E. Ozbay ◽  
I. Ederra ◽  
R. Gonzalo

The mutual coupling between elements of a multifrequency dipole antenna array is experimentally investigated byS-parameter measurements and planar near-field scanning of the radiated field. A multifrequency array with six dipoles is analyzed. In order to reduce the coupling between dipoles, a planar metasurface is placed atop the array acting as superstrate. The mutual coupling of the antenna elements in the absence and presence of the superstrate is presented comparatively. Between 3 and 20 dB mutual coupling reduction is achieved when the superstrate is used. By scanning the field radiated by the antennas and far-field measurements of the radiation pattern, it is observed that the superstrate confines the radiated power, increases the boresight radiation, and reduces the endfire radiation.


2021 ◽  
Author(s):  
Ali Durmus ◽  
Rifat KURBAN ◽  
Ercan KARAKOSE

Abstract Today, the design of antenna arrays is very important in providing effective and efficient wireless communication. The purpose of antenna array synthesis is to obtain a radiation pattern with low side lobe level (SLL) at a desired half power beam width (HPBW) in far-field. The amplitude and position values ​​of the array elements can be optimized to obtain a radiation pattern with suppressed SLLs. In this paper swarm-based meta-heuristic algorithms such as Particle Swarm Optimization (PSO), Artificial Bee Colony (ABC), Mayfly algorithm (MA) and Jellyfish Search (JS) algorithms are compared to realize optimal design of linear antenna arrays. Extensive experiments are conducted on designing 10, 16, 24 and 32-element linear arrays by determining the amplitude and positions. Experiments are repeated 30 times due to the random nature of swarm-based optimizers and statistical results show that performance of the novel algorithms, MA and JS, are better than well-known methods PSO and ABC.


2021 ◽  
Vol 10 (3) ◽  
pp. 58-70
Author(s):  
O. J. Famoriji ◽  
T. Shongwe

Failure of element (s) in antenna arrays impair (s) symmetry and lead to unwanted distorted radiation pattern. The replacement of defective elements in aircraft antennas is a solution to the problem, but it remains a critical problem in space stations. In this paper, an antenna array diagnosis technique based on multivalued neural network (mNN) inverse modeling is proposed. Since inverse analytical input-to-output formulation is generally a challenging and important task in solving the inverse problem of array diagnosis, ANN is a compelling alternative, because it is trainable and learns from data in inverse modelling. The mNN technique proposed is an inverse modelling technique, which accommodates measurements for output model. This network takes radiation pattern samples with faults and matches it to the corresponding position or location of the faulty elements in that antenna array. In addition, we develop a new training error function, which focuses on the matching of each training sample by a value of our proposed inverse model, while the remaining values are free, and trained to match distorted radiation patterns. Thereby, mNN learns all training data by redirecting the faulty elements patterns into various values of the inverse model. Therefore, mNN is able to perform accurate array diagnosis in an automated and simpler manner.


2018 ◽  
Vol 11 (4) ◽  
pp. 382-389
Author(s):  
Abhishek Kumar Awasthi ◽  
A. R. Harish

AbstractIn this paper, a compact wideband tightly-coupled dipole antenna array has been developed. Dipole elements are placed in the triangular lattice to reduce the side lobe level in the radiation pattern of one of the planes. To obtain the initial dimensions, 1-D infinite array analysis of the proposed array is carried out. The infinite array is designed to operate in 5–14.3 GHz (96.3% impedance bandwidth) frequency band. The antenna array can be used in C and X band applications. Inter-element coupling is utilized to achieve ultra-wideband performance in the proposed array. A 2 × 8 elements finite array is designed with the feed network. An ultra-wideband parallel strip to microstrip transition is used to feed the array elements. A metallic shielding for the feed network helps in reducing the back lobes. The overall size of the array with the reflector and the feed network is 148 mm × 224 mm × 54.5 mm. To validate the proposed concept, the antenna array is fabricated and tested. Impedance bandwidth of 2.8:1 along with broadside radiation pattern throughout the band of interest is observed.


2011 ◽  
Vol 62 (2) ◽  
pp. 113-116
Author(s):  
Marek Dvorský

Radiation Pattern Optimization by Loaded Impedance in the Base of Passive ElementThis article deals with optimizing the radiation pattern by using two vertical middle wave antenna arrays. Optimization is achieved by adding an appropriate impedance into the base of the passive antenna radiator. The proposed solution deals with finding the best value of the loaded impedance. The final result is to achieve the most effective shape of the radiation pattern. The proposed method was finally approved by measurement on a real middle wave antenna array.


2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
E.N. Mishchenko ◽  
◽  
S.E. Mishchenko ◽  
N.V. Shatskiy ◽  
◽  
...  

n the development of the existing statistical theory of antennas, new analytical relations are obtained for estimating the average radiation pattern of a digital antenna array. These ratios take into account the variance of rounding errors of the weight coefficients, errors in the amplitude and phase calibration of the antenna, jitter noise and rounding errors of the signal at the output of the analog-to-digital converter. It is shown that most of the factors affect the average level of the side lobes, as in analog antenna arrays. However, the variances of the phase calibration errors and the jitter noise determine the contribution of the new term, which has symmetry in the angular coordinate and has an extremums in the direction of the main beam of the antenna array and in the direction that is mirrored relative to the main beam. It is established that the variances of rounding errors depend on the signal-to-noise ratio and, when performing numerical studies, should be estimated based on the results of experimental studies. It is shown that digital processing in a sliding window reduces the average level of the side lobes by separating the spectral components of the signal and noise.


Author(s):  
Ali Durmus ◽  
Rifat Kurban

Abstract 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.


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