scholarly journals Average radiation pattern digital antenna array and a method for reducing the average level of side lobes.

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
E.N. Mishchenko ◽  
◽  
S.E. Mishchenko ◽  
N.V. Shatskiy ◽  
◽  
...  
Keyword(s):  
Antenna Array ◽  
Radiation Pattern ◽  
Antenna Arrays ◽  
Signal To Noise Ratio ◽  
Experimental Studies ◽  
Digital Processing ◽  
Average Level ◽  
Main Beam ◽  
Rounding Errors ◽  
Phase Calibration

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.

A Comparison of Swarm-Based Optimization Algorithms in Linear Antenna Array Synthesis

2021 ◽  
Author(s):  
Ali Durmus ◽  
Rifat KURBAN ◽  
Ercan KARAKOSE
Keyword(s):  
Antenna Array ◽  
Radiation Pattern ◽  
Antenna Arrays ◽  
Heuristic Algorithms ◽  
Beam Width ◽  
Side Lobe ◽  
Side Lobe Level ◽  
Linear Antenna ◽  
Half Power ◽  
Antenna Array Synthesis

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.

scholarly journals An Effective Antenna Array Diagnosis Method via Multivalued Neural Network Inverse Modeling Approach

2021 ◽  
Vol 10 (3) ◽  
pp. 58-70
Author(s):  
O. J. Famoriji ◽  
T. Shongwe
Keyword(s):  
Neural Network ◽  
Antenna Array ◽  
Radiation Pattern ◽  
Antenna Arrays ◽  
Inverse Modeling ◽  
Error Function ◽  
Training Sample ◽  
Inverse Model ◽  
Training Data ◽  
Inverse Modelling

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.

Study of the characteristics of a radio photon device for determining the phase difference of a radar signals

2021 ◽  
pp. 38-42
Author(s):  
Yaroslav N. Gusenitsa ◽  
Aleksandr L. Snegirev ◽  
Sergey A. Pokotilo
Keyword(s):  
Antenna Array ◽  
Phase Difference ◽  
Antenna Arrays ◽  
Output Signal ◽  
Experimental Studies ◽  
Radar Signal ◽  
Optical Modulator ◽  
Optical Modulators ◽  
Phased Antenna Arrays ◽  
Phased Antenna Array

The paper considers the problem of accurate calculation of the phase of the radar signal in relation to the receiving phased antenna arrays. Methods for determining the phase difference based on a comparison of the received signal with the local oscillator signal are listed, as well as a method based on the use of a radio-photon analog-to-digital converter for the output signal of the receiving phased antenna array. Their disadvantages are indicated. A method and a radio photon device are proposed that are devoid of these disadvantages. The method allows you to calculate the phase difference of the radar signal at the output of the electro-optical modulator and the output signal of the photodetector, taking into account the known values of the amplitudes and phase difference of the microwave signals at the input of the receiving elements of the phased antenna array. The radio-photon device allows you to implement this method and, unlike the known analogues, is based on the use of two parallel-connected electro-optical modulators constructed according to the scheme of the Mach-Zehnder interferometer. It is shown that the proposed radio photon device provides a higher accuracy of determining the phase of the radar signal in comparison with existing analogues. At the end of the work, an analysis of the results of experimental studies using the proposed method and a radio photon device is presented. According to the results of the experiment, it was found that the phase and phase differences vary linearly, and their maximum reaches π. In addition, the square of the amplitude of the optical signal at the input of the photon-electronic unit is proportional to the phase difference and inversely proportional to the ratio of the amplitudes of the output signals of the adjacent receiving elements of the phased antenna arrays.

scholarly journals Radiation Pattern Optimization by Loaded Impedance in the Base of Passive Element

2011 ◽  
Vol 62 (2) ◽  
pp. 113-116
Author(s):  
Marek Dvorský
Keyword(s):  
Antenna Array ◽  
Radiation Pattern ◽  
Antenna Arrays ◽  
Passive Element ◽  
Wave Antenna ◽  
Best Value ◽  
Passive Antenna

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.

scholarly journals Calibration of Siberian Radioheliograph antenna gains using redundancy

2021 ◽  
Vol 7 (4) ◽  
pp. 104-110
Author(s):  
Mariia Globa ◽  
Sergey Lesovoi
Keyword(s):  
Antenna Array ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
High Dynamic Range ◽  
Special Care ◽  
System Of Equations ◽  
Signal To Noise ◽  
Double Step ◽  
Phase Calibration ◽  
High Dynamic

The paper describes application of standard gain calibration using redundancy for a 48-antenna prototype of Siberian Radioheliograph. Traditionally, for calibration, the visibilities were measured only between adjacent antennas since they have the highest signal-to-noise ratio and are sufficient for phase calibration. We have shown that this limited set of visibilities did not allow using the antenna array redundancy potential and obtaining images with a high dynamic range on a permanent basis. Images without amplitude calibration contain many artifacts and require special care when analyzed. The inclusion of visibility measurement between antennas with a double step made it possible to significantly increase the accuracy of solving the system of equations for amplitudes. Images constructed using both phase and amplitude calibrations do not have visible artifacts and are more reliable.

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
Keyword(s):  
Antenna Array ◽  
Radiation Pattern ◽  
Antenna Arrays ◽  
Dipole Antenna ◽  
Paper Substrate ◽  
Final Shape ◽  
Flexible Antenna ◽  
Folded Dipole

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.

scholarly journals Hybrid Differential Evolution with Biogeography-Based Optimization for Design of a Reconfigurable Antenna Array with Discrete Phase Shifters

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Xiangtao Li ◽  
Minghao Yin
Keyword(s):  
Differential Evolution ◽  
Antenna Array ◽  
Antenna Arrays ◽  
Dynamic Range ◽  
Phase Shifters ◽  
Main Beam ◽  
Reconfigurable Antenna ◽  
Reconfigurable Design ◽  
Low Sidelobe ◽  
Discrete Phase

Multibeam antenna arrays have important applications in communications and radar. This paper presents a new method of designing a reconfigurable antenna with quantized phase excitations using a new hybrid algorithm, called DE/BBO. The reconfigurable design problem is to find the element excitation that will result in a sector pattern main beam with low sidelobes with additional requirement that the same excitation amplitudes applied to the array with zero-phase should be in a high directivity, low sidelobe pencil-shaped main beam. In order to reduce the effect of mutual coupling between the antenna-array elements, the dynamic range ratio is minimized. Additionally, compared with the continuous realization and subsequent quantization, experimental results indicate that the performance of the discrete realization of the phase excitation value can be improved. In order to test the performances of hybrid differential evolution with biogeography-based optimization, the results of some state-of-art algorithms are considered, for the purposed of comparison. Experiment results indicate the better performance of the DE/BBO.

scholarly journals Investigation on SIW Slot Antenna Array with Beam Scanning Ability

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Yanfei Li ◽  
Yang Li
Keyword(s):  
Genetic Algorithm ◽  
Antenna Array ◽  
Antenna Arrays ◽  
Beam Width ◽  
Side Lobe ◽  
Slot Antenna ◽  
Main Beam ◽  
Side Lobe Level ◽  
Substrate Integrated Waveguide ◽  
Beam Scanning

A sparse substrate integrated waveguide (SIW) slot antenna array and its application on phase scanning are studied in this paper. The genetic algorithm is used to optimize the best arrangement for 8-element and 7-element sparse arrays over an aperture of 4.5λ0. Antenna arrays with feeding networks, for steering the main beam pointing to 0° and −15°, are demonstrated with the SIW technology. The comparison between the sparse array and the conventional uniformly spaced array with the same aperture are presented, which suggest that the same beam width can be obtained with the gain decreased by 0.5 or 1 dBi and the number of element reduced by 2 or 3, respectively. The sparse antenna array with beam scanning ability presented in this paper shows that, while the beam scanning in the range of ±15°, the gain fluctuation is less than 0.3 dBi and the side lobe level is lower than −10 dB.

scholarly journals Decoupling of Multifrequency Dipole Antenna Arrays for Microwave Imaging Applications

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
E. Saenz ◽  
K. Guven ◽  
E. Ozbay ◽  
I. Ederra ◽  
R. Gonzalo
Keyword(s):  
Antenna Array ◽  
Radiation Pattern ◽  
Antenna Arrays ◽  
Mutual Coupling ◽  
Near Field ◽  
Field Measurements ◽  
Dipole Antenna ◽  
Far Field ◽  
Radiated Power ◽  
Near Field Scanning

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.

Optimum design of linear and circular antenna arrays using equilibrium optimization algorithm

2021 ◽  
pp. 1-12
Author(s):  
Ali Durmus ◽  
Rifat Kurban
Keyword(s):  
Antenna Array ◽  
Radiation Pattern ◽  
Antenna Arrays ◽  
Optimization Algorithm ◽  
Communication Systems ◽  
Control Volume ◽  
Optimization Technique ◽  
Beam Width ◽  
Side Lobe ◽  
Side Lobe Level

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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