Support vector regression for near-field multifocused antenna arrays considering mutual coupling

2015 ◽  
Vol 29 (2) ◽  
pp. 146-156 ◽  
Author(s):  
Jana Álvarez Muñiz ◽  
Rafael G. Ayestarán ◽  
Jaime Laviada ◽  
Fernando Las-Heras
Keyword(s):  
Support Vector Regression ◽  
Antenna Arrays ◽  
Mutual Coupling ◽  
Near Field ◽  
Support Vector

scholarly journals Support Vector Regression for the Modeling and Synthesis of Near-Field Focused Antenna Arrays

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1352 ◽  
Author(s):  
Rafael González Ayestarán
Keyword(s):  
Support Vector Regression ◽  
Antenna Arrays ◽  
Near Field ◽  
Computational Cost ◽  
Support Vector ◽  
Analysis Tool ◽  
Training Samples ◽  
Learning Capabilities ◽  
Novel Method ◽  
The Individual

The powerful support vector regression framework is proposed in a novel method for near-field focusing using antenna arrays. By using this machine-learning method, the set of weights required in the elements of an array can be calculated to achieve an assigned near-field distribution focused on one or more positions. The computational cost is concentrated in an initial training process so that the trained system is fast enough for applications where moving devices are involved. The increased learning capabilities of support vector machines allow using a reduced number of training samples. Thus, these training samples may be generated with a prototype or a convenient electromagnetic analysis tool, and hence realistic effects, such as coupling or the individual radiation patterns of the elements of the arrays, are accounted for. Illustrative examples are presented.

scholarly journals Near-field sound source localization using principal component analysis–multi-output support vector regression

2020 ◽  
Vol 16 (4) ◽  
pp. 155014772091640
Author(s):  
Lanmei Wang ◽  
Yao Wang ◽  
Guibao Wang ◽  
Jianke Jia
Keyword(s):  
Principal Component Analysis ◽  
Support Vector Regression ◽  
Covariance Matrix ◽  
Signal To Noise Ratio ◽  
Near Field ◽  
Principal Component ◽  
Component Analysis ◽  
Support Vector ◽  
Signal To Noise ◽  
Noise Ratio

In this article, principal component analysis method, which is applied to image compression and feature extraction, is introduced into the dimension reduction of input characteristic variable of support vector regression, and a method of joint estimation of near-field angle and range based on principal component analysis dimension reduction is proposed. Signal-to-noise ratio and calculation amount are the decisive factors affecting the performance of the algorithm. Principal component analysis is used to fuse the main characteristics of training data and discard redundant information, the signal-to-noise ratio is improved, and the calculation amount is reduced accordingly. Similarly, support vector regression is used to model the signal, and the upper triangular elements of the signal covariance matrix are usually used as input features. Since the covariance matrix has more upper triangular elements, training it as a feature input will affect the training speed to some extent. Principal component analysis is used to reduce the dimensionality of the upper triangular element of the covariance matrix of the known signal, and it is used as the input feature of the multi-output support vector regression machine to construct the near-field parameter estimation model, and the parameter estimation of unknown signal is herein obtained. Simulation results show that this method has high estimation accuracy and training speed, and has strong adaptability at low signal-to-noise ratio, and the performance is better than that of the back-propagation neural network algorithm and the two-step multiple signal classification algorithm.

scholarly journals Source Localization of EM Waves in the Near-Field of Spherical Antenna Array in the Presence of Unknown Mutual Coupling

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Oluwole John Famoriji ◽  
Thokozani Shongwe
Keyword(s):  
Antenna Array ◽  
Source Localization ◽  
Antenna Arrays ◽  
Mutual Coupling ◽  
Near Field ◽  
Ground Truth ◽  
Doa Estimation ◽  
Measured Data ◽  
Practical Applications ◽  
Spherical Antenna

To obtain an antenna array with isotropic radiation, spherical antenna array (SAA) is the right array configuration. The challenges of locating signals transmitted within the proximity of antenna array have been investigated considerably in the literature. However, near-field (NF) source localization of signals has hitherto not been investigated effectively using SAA in the presence of mutual coupling (MC). MC is another critical problem in antenna arrays. This paper presents an NF range and direction-of-arrival (DoA) estimation technique via the direction-independent and signal invariant spherical harmonics (SH) characteristics in the presence of mutual coupling. The energy of electromagnetic (EM) signal on the surface of SAA is captured successfully using a proposed pressure interpolation approach. The DoA estimation within the NF region is then calculated via the distribution of pressure. The direction-independent and signal invariant characteristics, which are SH features, are obtained using the DoA estimates in the NF region. We equally proposed a learning scheme that uses the source activity detection and convolutional neural network (CNN) to estimate the range of the NF source via the direction-independent and signal invariant features. Considering the MC problem and using the DoA estimates, an accurate spectrum peak in the multipath situation in conjunction with MC and a sharper spectrum peak from a unique MC structure and smoothing algorithms are obtained. For ground truth performance evaluation of the SH features within the context of NF localization, a numerical experiment is conducted and measured data were used for analysis to incorporate the MC and consequently computed the root mean square error (RMSE) of the source range and NF DoA estimate. The results obtained from numerical experiments and measured data indicate the validity and effectiveness of the proposed approach. In addition, these results are motivating enough for the deployment of the proposed method in practical applications.

Research on Patch Near-Field Acoustic Holography

2011 ◽  
Vol 105-107 ◽  
pp. 196-199 ◽  
Author(s):  
Hai Chao Zhu ◽  
Zhi Min Chen ◽  
Xiang Hua Du ◽  
Rong Fu Mao
Keyword(s):  
Support Vector Regression ◽  
Sound Pressure ◽  
Near Field ◽  
Measured Data ◽  
Experimental Results ◽  
Support Vector ◽  
Reconstruction Accuracy ◽  
Acoustic Holography ◽  
Training Samples ◽  
Regression Functions

Support vector regression is used to establish a kind of patch near-field acoustic holography. The regression functions are constructed by treating the measured data on the patch holography as training samples, and then the data outside the measurement aperture are extrapolated. The experimental results show that the extrapolation of the sound pressure outside the smaller initial hologram aperture may be realized easily and effectively, and the reconstruction accuracy is satisfactory.

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.

scholarly journals High-isolation antenna array using SIW and realized with a graphene layer for sub-terahertz wireless applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Alibakhshikenari ◽  
Bal S. Virdee ◽  
Shahram Salekzamankhani ◽  
Sonia Aïssa ◽  
Chan H. See ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Antenna Arrays ◽  
Integrated Circuit ◽  
Mutual Coupling ◽  
Near Field ◽  
Dielectric Substrate ◽  
Patch Antennas ◽  
Reference Array ◽  
Radiation Properties ◽  
Array Structures

AbstractThis paper presents the results of a study on developing an effective technique to increase the performance characteristics of antenna arrays for sub-THz integrated circuit applications. This is essential to compensate the limited power available from sub-THz sources. Although conventional array structures can provide a solution to enhance the radiation-gain performance however in the case of small-sized array structures the radiation properties can be adversely affected by mutual coupling that exists between the radiating elements. It is demonstrated here the effectiveness of using SIW technology to suppress surface wave propagations and near field mutual coupling effects. Prototype of 2 × 3 antenna arrays were designed and constructed on a polyimide dielectric substrate with thickness of 125 μm for operation across 0.19–0.20 THz. The dimensions of the array were 20 × 13.5 × 0.125 mm3. Metallization of the antenna was coated with 500 nm layer of Graphene. With the proposed technique the isolation between the radiating elements was improved on average by 22.5 dB compared to a reference array antenna with no SIW isolation. The performance of the array was enhanced by transforming the patch to exhibit metamaterial characteristics. This was achieved by embedding the patch antennas in the array with sub-wavelength slots. Compared to the reference array the metamaterial inspired structure exhibits improvement in isolation, radiation gain and efficiency on average by 28 dB, 6.3 dBi, and 34%, respectively. These results show the viability of proposed approach in developing antenna arrays for application in sub-THz integrated circuits.

scholarly journals A Measurement System for the Position and Phase Errors of the Elements in an Antenna Array Subject to Mutual Coupling

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Tore Lindgren ◽  
Johan Borg
Keyword(s):  
Measurement System ◽  
Antenna Arrays ◽  
Mutual Coupling ◽  
Near Field ◽  
Scattering Matrix ◽  
Antenna Element ◽  
Local Measurement ◽  
Phase Errors ◽  
The Individual ◽  
Probe Array

When deploying large antenna arrays in arctic environments, a local measurement system may be necessary in order to ensure control over the position and phase of the individual antenna elements. In this paper, a method of estimating the position and phase of each individual antenna element in the presence of mutual coupling is presented. It uses both measurements of the scattering matrix in the array and measurements of the electric field using a minimum of four probes located in the near field of the array. Simulations show that the method gives accurate results even in the presence of noise in the measurements. The geometry of the probe-array system affects the performance significantly.

scholarly journals Reconfigurable Antenna Arrays with Multiple Requirements: A Versatile 3D Approach

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Massimiliano Comisso ◽  
Giulia Buttazzoni ◽  
Roberto Vescovo
Keyword(s):  
Antenna Arrays ◽  
Mutual Coupling ◽  
Dynamic Range ◽  
Near Field ◽  
Field Pattern ◽  
Deterministic Method ◽  
Iterative Minimization ◽  
Array Structures ◽  
Far Field Pattern ◽  
Ratio Reduction

This paper proposes a deterministic method for the 3D synthesis of antenna arrays that jointly accounts for far-field pattern reconfigurability, polarization setting, dynamic range ratio reduction, and near-field control. The conceived algorithm, which generalizes some existing solutions, relies on a weighted cost function, whose iterative minimization is accomplished by properly derived closed-form expressions. This feature, combined with the possibility of selecting the weighting parameters, provides a fast and versatile approach, whose capabilities are numerically checked by considering different synthesis problems and array structures in the presence of mutual coupling.

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