This paper presented a compressive sensing (CS) calibration technique that simultaneously measures all the element excitations of a 2×2 active phased antenna array (APAA) instantaneously. The power patterns of the rectangular 2×2 APAA element are synchronized to orthogonally cross multiplicative sub-array system applying compressive sensing in achieving an array thinning along two 1-D sub-arrays for a fixed steered beam radiation. The far field radiation pattern direction of the 2×2 APAA is examined considering the mutual effect, complex excitation of the amplitude and phase of the antenna elements placed on the x and y axes. The unwanted array excitation with errors are calibrated using minimization vector as a standard basic pursuit problem in compressive sensing technique for the 2×2 APAA calibration. The elements amplitude and phase shift variation are compared with reference state 0 in order to evaluate the faulty error array elements. The performance evaluation of this proposed technique is measured and demonstrated to validate the effectiveness of the proposed antenna calibration technique.
Elements Space and Amplitude Perturbation Using Genetic Algorithm for Antenna...CSCJournals
A simple and fast genetic algorithm (GA) developed to reduce the sidelobes in non-uniformly spaced linear antenna arrays. The proposed GA algorithm optimizes two vectors of variables to increase the Main lobe to Sidelobe power ratio (M/S) of array’s radiation pattern. The algorithm, in the first phase calculates the positions of the array elements and in the second phase, it manipulates the amplitude of excitation signals for each element. The simulations performed for 16 and 24 elements array structure. The results indicated that M/S improved in first phase from 13.2 to over 22.2dB meanwhile the half power beamwidth (HPBW) left almost unchanged. After element replacement, in the second phase, by using amplitude tapering further improvement up to 32dB was achieved. Also, the simulations shown that after element space perturbation, some antenna elements can be merged together without any performance degradation in radiation pattern in terms of gain and sidelobes level.
This document presents a low-cost method for electromagnetic signal spectral analysis and direction finding using a two-element time-modulated antenna array and multiple signal classification (MUSIC) algorithms. It describes a prototype array constructed using quarter-wave monopoles as antenna elements switched using PIN diodes. Measurements show the array output is phase modulated depending on signal arrival angle, producing a directional pattern at the carrier frequency and null at the first harmonic. MUSIC algorithms are applied to estimate signal directions from the received signals. The method provides a low-cost alternative to conventional direction finding techniques with potential applications in wireless communications and homeland security.
High Resolution Method using Patch Circular Array IJECEIAES
Smart antennas have recently received increasing for improving the performance of wireless radio systems. In this research article, we have used a patch antenna using uniform circular arrays (UCA) with central element for direction of arrival (DOA). A central element was added to arrays in order to increase steering capability of the proposed array. This geometry is used to determine the elevation and azimuth based on two famous algorithms of high resolution method: Matrix Pencil method (MP) and MUltiple Signal Classification (MUSIC).The comparison results demonstrate clearly that the matrix pencil is more accurate and stable to estimation of direction of arrival compared to the MUSIC algorithm.
Rabid Euclidean direction search algorithm for various adaptive array geometriesjournalBEEI
This document summarizes the Rabid Euclidean direction search (REDS) algorithm for adaptive beamforming in different antenna array geometries. The REDS algorithm is analyzed for linear, circular, and planar array configurations. Simulation results show that the REDS algorithm provides significant improvements over other algorithms, including faster convergence, lower mean square error, better interference reduction, and lower sidelobe levels. Specifically, the REDS algorithm cyclically searches and updates weights along individual Euclidean directions to minimize error, offering computational advantages over algorithms like least mean square and recursive least squares.
This document summarizes an article from the International Journal of Advanced Research in Engineering and Technology that describes an adaptive antenna array that uses an LMS algorithm. The article discusses how adaptive antenna arrays can automatically track satellite signals by adjusting the phase and amplitude of antenna elements. It presents the LMS algorithm as a way to calculate the complex weights for each antenna element to direct the main beam toward the desired signal while placing nulls toward interference. MATLAB simulations demonstrate how the LMS algorithm updates the element weights to achieve beam steering toward different desired signal angles and insert nulls at interference angles. The simulations show an increase in directivity and reduction in beamwidth after applying LMS adaptive beamforming.
Implementation of Digital Beamforming Technique for Linear Antenna Arraysijsrd.com
A digital Beamforming technique used for increased channel capacity and also increased signal to noise and interference ratio. In smart antenna, different type of radiation pattern of an antenna can be changed either by selecting appropriate weights or by changing the array geometry. This paper presented based on auxiliary phase algorithm by using this algorithm in linear antenna array determine the array pattern approximating the auxiliary function in both amplitude and phase. Cost function involving auxiliary function and array pattern is minimized by modifying the pattern.
Comparitive analysis of doa and beamforming algorithms for smart antenna systemseSAT Journals
Abstract This paper revolves around the implementation of Direction of arrival and Adaptive beam-forming algorithms for Smart Antenna Systems. This paper also investigates the implementation of algorithms on various planner array geometries viz. circular and rectangular. Music algorithm is primarily finds the possible location of desired user and adaptive beam-forming algorithms such as LMS, RLS and CMA algorithms adapts the weights of the array. DOA estimation gives the maximum peak of spectrum with respect to angle of arrival where the desired user is supposed to exist. After DOA estimation weights of array antenna are changed with the changing received signal. This methodology is called as Spectral estimation, which allows the antenna pattern to steer in desired direction estimated by DOA and simultaneously null out the interfering signals. Rate of convergence is the major criterion for comparison for adaptive beam-forming algorithms. Keywords: DOA, MUSIC, LMS, RLS, CMA, SAS.
Diagnosis of Faulty Sensors in Antenna Array using Hybrid Differential Evolut...IJECEIAES
In this work, differential evolution based compressive sensing technique for detection of faulty sensors in linear arrays has been presented. This algorithm starts from taking the linear measurements of the power pattern generated by the array under test. The difference between the collected compressive measurements and measured healthy array field pattern is minimized using a hybrid differential evolution (DE). In the proposed method, the slow convergence of DE based compressed sensing technique is accelerated with the help of parallel coordinate decent algorithm (PCD). The combination of DE with PCD makes the minimization faster and precise. Simulation results validate the performance to detect faulty sensors from a small number of measurements.
Elements Space and Amplitude Perturbation Using Genetic Algorithm for Antenna...CSCJournals
A simple and fast genetic algorithm (GA) developed to reduce the sidelobes in non-uniformly spaced linear antenna arrays. The proposed GA algorithm optimizes two vectors of variables to increase the Main lobe to Sidelobe power ratio (M/S) of array’s radiation pattern. The algorithm, in the first phase calculates the positions of the array elements and in the second phase, it manipulates the amplitude of excitation signals for each element. The simulations performed for 16 and 24 elements array structure. The results indicated that M/S improved in first phase from 13.2 to over 22.2dB meanwhile the half power beamwidth (HPBW) left almost unchanged. After element replacement, in the second phase, by using amplitude tapering further improvement up to 32dB was achieved. Also, the simulations shown that after element space perturbation, some antenna elements can be merged together without any performance degradation in radiation pattern in terms of gain and sidelobes level.
This document presents a low-cost method for electromagnetic signal spectral analysis and direction finding using a two-element time-modulated antenna array and multiple signal classification (MUSIC) algorithms. It describes a prototype array constructed using quarter-wave monopoles as antenna elements switched using PIN diodes. Measurements show the array output is phase modulated depending on signal arrival angle, producing a directional pattern at the carrier frequency and null at the first harmonic. MUSIC algorithms are applied to estimate signal directions from the received signals. The method provides a low-cost alternative to conventional direction finding techniques with potential applications in wireless communications and homeland security.
High Resolution Method using Patch Circular Array IJECEIAES
Smart antennas have recently received increasing for improving the performance of wireless radio systems. In this research article, we have used a patch antenna using uniform circular arrays (UCA) with central element for direction of arrival (DOA). A central element was added to arrays in order to increase steering capability of the proposed array. This geometry is used to determine the elevation and azimuth based on two famous algorithms of high resolution method: Matrix Pencil method (MP) and MUltiple Signal Classification (MUSIC).The comparison results demonstrate clearly that the matrix pencil is more accurate and stable to estimation of direction of arrival compared to the MUSIC algorithm.
Rabid Euclidean direction search algorithm for various adaptive array geometriesjournalBEEI
This document summarizes the Rabid Euclidean direction search (REDS) algorithm for adaptive beamforming in different antenna array geometries. The REDS algorithm is analyzed for linear, circular, and planar array configurations. Simulation results show that the REDS algorithm provides significant improvements over other algorithms, including faster convergence, lower mean square error, better interference reduction, and lower sidelobe levels. Specifically, the REDS algorithm cyclically searches and updates weights along individual Euclidean directions to minimize error, offering computational advantages over algorithms like least mean square and recursive least squares.
This document summarizes an article from the International Journal of Advanced Research in Engineering and Technology that describes an adaptive antenna array that uses an LMS algorithm. The article discusses how adaptive antenna arrays can automatically track satellite signals by adjusting the phase and amplitude of antenna elements. It presents the LMS algorithm as a way to calculate the complex weights for each antenna element to direct the main beam toward the desired signal while placing nulls toward interference. MATLAB simulations demonstrate how the LMS algorithm updates the element weights to achieve beam steering toward different desired signal angles and insert nulls at interference angles. The simulations show an increase in directivity and reduction in beamwidth after applying LMS adaptive beamforming.
Implementation of Digital Beamforming Technique for Linear Antenna Arraysijsrd.com
A digital Beamforming technique used for increased channel capacity and also increased signal to noise and interference ratio. In smart antenna, different type of radiation pattern of an antenna can be changed either by selecting appropriate weights or by changing the array geometry. This paper presented based on auxiliary phase algorithm by using this algorithm in linear antenna array determine the array pattern approximating the auxiliary function in both amplitude and phase. Cost function involving auxiliary function and array pattern is minimized by modifying the pattern.
Comparitive analysis of doa and beamforming algorithms for smart antenna systemseSAT Journals
Abstract This paper revolves around the implementation of Direction of arrival and Adaptive beam-forming algorithms for Smart Antenna Systems. This paper also investigates the implementation of algorithms on various planner array geometries viz. circular and rectangular. Music algorithm is primarily finds the possible location of desired user and adaptive beam-forming algorithms such as LMS, RLS and CMA algorithms adapts the weights of the array. DOA estimation gives the maximum peak of spectrum with respect to angle of arrival where the desired user is supposed to exist. After DOA estimation weights of array antenna are changed with the changing received signal. This methodology is called as Spectral estimation, which allows the antenna pattern to steer in desired direction estimated by DOA and simultaneously null out the interfering signals. Rate of convergence is the major criterion for comparison for adaptive beam-forming algorithms. Keywords: DOA, MUSIC, LMS, RLS, CMA, SAS.
Diagnosis of Faulty Sensors in Antenna Array using Hybrid Differential Evolut...IJECEIAES
In this work, differential evolution based compressive sensing technique for detection of faulty sensors in linear arrays has been presented. This algorithm starts from taking the linear measurements of the power pattern generated by the array under test. The difference between the collected compressive measurements and measured healthy array field pattern is minimized using a hybrid differential evolution (DE). In the proposed method, the slow convergence of DE based compressed sensing technique is accelerated with the help of parallel coordinate decent algorithm (PCD). The combination of DE with PCD makes the minimization faster and precise. Simulation results validate the performance to detect faulty sensors from a small number of measurements.
Fault Tolerant Matrix Pencil Method for Direction of Arrival Estimationsipij
Continuing to estimate the Direction-of-arrival (DOA) of the signals impinging on the antenna array, even when a few elements of the underlying Uniform Linear Antenna Array (ULA) fail to work will be of practical interest in RADAR, SONAR and Wireless Radio Communication Systems. This paper proposes a new technique to estimate the DOAs when a few elements are malfunctioning. The technique combines Singular Value Thresholding (SVT) based Matrix Completion (MC) procedure with the Direct Data Domain (D3) based Matrix Pencil (MP) Method. When the element failure is observed, first, the MC is performed to recover the missing data from failed elements, and then the MP method is used to estimate the DOAs. We also, propose a very simple technique to detect the location of elements failed, which is required to perform MC procedure. We provide simulation studies to demonstrate the performance and usefulness of the proposed technique. The results indicate a better performance, of the proposed DOA estimation scheme under different antenna failure scenarios.
This document summarizes research on using particle swarm optimization (PSO) to enhance the radiation pattern of a phase array antenna. It begins by introducing the problem of high sidelobes in phase array antenna patterns. It then provides background on phased array antennas and array pattern modeling. A 24-element linear array modeled in MATLAB is used as a case study. Standard PSO and a modified PSO algorithm are applied to optimize the current excitations and minimize the sidelobe levels. Simulation results show that both PSO approaches reduce sidelobes compared to uniform excitation, with the modified PSO performing better. Overall, the document presents research on using computational optimization methods to improve phase array antenna radiation patterns by controlling sidelobe levels
Enhancing the Radiation Pattern of Phase Array Antenna Using Particle Swarm O...IOSR Journals
The document describes a study that uses particle swarm optimization to enhance the radiation pattern of a phase array antenna by minimizing sidelobe levels. It first provides background on issues with high sidelobes in phase array antennas, such as power losses and interference. It then summarizes previous research using techniques like genetic algorithms for antenna array optimization. The study models the radiation pattern of linear arrays with different element numbers and calculates gain, finding that gain increases with more elements. However, sidelobe levels also increase relatively. Therefore, the study proposes using particle swarm optimization to optimize current excitation and control sidelobe levels while maintaining a narrow beamwidth.
performance analysis of MUSIC and ESPRIT DOA estimation used in adaptive arra...CSCJournals
MUSIC and ESPRIT DOA Estimaion algorithms are widely used in adaptive array to locate the desired desired signal.MUSIC is found to be more stable and accurate and widely used inthe design of adaptive array.
This document proposes an adaptive scheme for measuring signal parameters for generator monitoring and protection using adaptive orthogonal filters. The algorithm adapts the filter data window length and coefficients according to a coarse estimation of the signal frequency, allowing accurate measurements over a wide frequency band including during generator start-up. Measured signals are also used to train artificial neural networks to classify generator operation modes and detect phenomena like pole slipping and out-of-step conditions. The document describes the adaptive measurement scheme, provides an example using signals from simulations, and discusses using a genetic algorithm to optimize the design of an artificial neural network-based out-of-step protection system.
Simulation of an adaptive digital beamformer using matlabIJARBEST JOURNAL
Beam forming is the process of combining the weighted signals received on an array of
sensors to improve the directionality. Adaptive beamforming is the ability of the beamformer to
receive the signal only from the desired direction and to reject all other signals from undesired
directions. The weight vector for the adaptive beamformer continuously changes based on some
adaptive algorithm. Therefore, adaptive digital beam formers can point the antenna to the signal
direction without changing the physical architecture of the array antenna. The beam pointing
direction can be varied electronically with this technique. This paper focuses on Least Mean
Square (LMS) adaptive algorithm.
IRJET- Performance Evaluation of DOA Estimation using MUSIC and Beamformi...IRJET Journal
This document presents a simulation study comparing the MUSIC algorithm and LMS adaptive beamforming algorithm for direction of arrival (DOA) estimation and beamforming in a smart antenna system. The MUSIC algorithm uses eigendecomposition to estimate the DOA of multiple signals and finds the position location of the desired user. The LMS algorithm then adapts the beam pattern by adjusting weights to maximize gain towards the desired user while nulling interference from other directions. The simulation results show sharp peaks in the MUSIC spectrum to accurately locate the desired user and deep nulls in the LMS beam pattern to suppress interference.
Smart Antenna is a device with signal processing
capability combining multiple antenna elements to optimize its
radiation and reception patterns as per designed specifications.
Smart antennas basically comprise of two functionalities, i.e.,
Direction of Arrival and Beamforming. This paper explains the
estimation of Direction of Arrival using MLM method and a
novel approach called MUltiple Signal Classification which takes
advantage of orthogonal property and performs subspace
computation. With a comparative study of both the algorithms,
we shall prove the advantages of MUltiple Signal Classification
over the MLM method with the aid of MATLAB
Direction of Arrival Estimation Based on MUSIC Algorithm Using Uniform and No...IJERA Editor
In signal processing, the direction of arrival (DOA) estimation denotes the direction from which a propagating wave arrives at a point, where a set of antennas is located. Using the array antenna has an advantage over the single antenna in achieving an improved performance by applying Multiple Signal Classification (MUSIC) algorithm. This paper focuses on estimating the DOA using uniform linear array (ULA) and non-uniform linear array (NLA)of antennas to analyze the performance factors that affect the accuracy and resolution of the system based on MUSIC algorithm. The direction of arrival estimation is simulated on a MATLAB platform with a set of input parameters such as array elements, signal to noise ratio, number of snapshots and number of signal sources. An extensive simulation has been conducted and the results show that the NLA with DOA estimation for co-prime array can achieve an accurate and efficient DOA estimation
A Fault Detection and Classification Method for SC Transmission Line Using Ph...paperpublications3
Abstract: In this paper, fault detection and classification for Series Compensated Line (SCL) using phasor measurement unit is presented. The algorithm presented in this paper uses the PMU synchronized measurements and not depends on the data to be provided by the electricity utility. The compensated line parameters and Thevenin’s equivalent (TE) of the system at SCL terminals are calculated online, using three independent sets of pre-fault phasor measurements. The accuracy of fault location is performed with respect to fault location/position, types of fault, fault angle. The accuracy of the algorithm is simulated in MATLAB for 9-bus transmission system.
Signal processing with frequency and phase shift keying modulation in telecom...TELKOMNIKA JOURNAL
In this paper represents research improving effectiveness of signal processing in telecommunication devices especially for its part, which relates to providing its noise resistance in conditions of noise and interference. This objective has been achieved through development of methods and means for optimization of filtering devices and semigraphical interpretation of clock synchronization systems in telecommunications with frequency shift keying on the base of stochastic models what determines relevance of the subject. Separately, in an article considered the urgent task is using of modified synchronization methods based on the interference influence of adjacent symbols on the phase criterion tract, in particular the use of the modified synchronization scheme, in order to get a formalized outlook representation of the synchronization schemas based on the polyphase structures with using a bank of filters, that allows to improve the characteristics of digital telecommunication channels. This work is devoted to the examination and modeling of these ways. The proposed ideas and results for the construction of synchronization systems can be used in modern means of telecommunication.
A Survey on Applications of Neural Networks and Genetic Algorithms in Fault D...IOSR Journals
This document summarizes research on using neural networks and genetic algorithms for fault diagnosis in antenna arrays. It provides background on smart antenna arrays and issues with traditional fault diagnosis methods. It then describes how neural networks like multilayer perceptrons and radial basis function networks can be trained to map damaged radiation patterns to faulty antenna locations. Genetic algorithms are also discussed as an approach to minimize differences between measured and expected radiation patterns. Various studies applying these methods to different antenna array configurations are summarized, demonstrating the effectiveness of neural networks and genetic algorithms for fast and accurate fault diagnosis in antenna arrays.
The document describes a hybrid method for simultaneously calculating the resonant frequencies of rectangular, circular, and triangular microstrip antennas (MSAs). The hybrid method combines an artificial neural network (ANN) and fuzzy inference system (FIS). The ANN is first used to compute resonant frequencies, and the fuzzy inference system corrects any inaccuracies in the ANN computations. The hybrid method allows for a single model to calculate resonant frequencies across different antenna geometries simultaneously. Results from the hybrid method show very good agreement with experimental data in the literature, improving upon results from previous single neural network models.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Array diagnosis using compressed sensing in near fieldAlexander Decker
This document summarizes a technique for diagnosing faults in antenna arrays using compressed sensing on near-field measurement data. The technique aims to reduce measurement time by acquiring data from fewer measurement points compared to traditional methods like back-propagation. It does this by taking the difference between near-field measurements of a reference array without faults and the array under test to create a sparse "innovation vector". This vector is then reconstructed using an L1-norm regularization technique from compressed sensing. Numerical examples on a 289-element array show the technique can accurately detect up to 3 faulty elements from a small number of measurement points on the order of KlogN, where K is the number of faults.
Assessment of quality indicators of the automatic control system influence of...TELKOMNIKA JOURNAL
This work concentrates the analysis of the system of automatic control of the directive diagram of the moving active electronically scanned array with a limited number of transceiver modules. The analysis revealed a number of shortcomings that lead to a significant increase in standard deviations, quadratic integral estimates, and an increase in transient time. The identified disadvantages lead to a decrease in the efficiency of the antenna system, an increase in the error rate at the reception, the inability of the system to react to disturbances applied to any point of the system in the event of a mismatch of a given signal/noise level. In accordance with the analysis, the mathematical model of the automatic control system of the directional diagram of the moving active electronically scanned array was considered, considering this a new method of estimating the quality indicators of the automatic control diagram of the directional diagram of the active electronically scanned array in a random setting and disturbing action was developed. The difference between the proposed method and the existing method is in the construction of an automatic control system with differential coupling equivalent to the combination due to the introduction of derivatives of the random setting action of the open compensation connection.
This document analyzes and compares the performance of different adaptive beamforming techniques for smart antennas. It describes switched beamforming, which uses fixed beams, and adaptive beamforming techniques that use algorithms like LMS, SMI, RLS, CGA, CMA, and LSCMA to form an adaptive beam. It simulates these algorithms using MATLAB for a uniform linear array and compares their ability to direct the main beam towards the desired user while nulling interference. The LMS, SMI, RLS, CMA and LSCMA algorithms are found to perform well at directing the beam to the desired user, with LMS having good interference rejection and RLS providing the fastest convergence but highest computational cost.
This document describes a study on estimating the direction of arrival (DOA) of signals using a conformal antenna array and the MUSIC algorithm. A seven-element conformal antenna array is designed using microstrip patch antennas mounted on a truncated hexagonal pyramid structure. The MUSIC algorithm is derived for this conformal antenna array to estimate the DOA. Simulation software will be used to analyze the antenna array's performance parameters like bandwidth, return loss, gain, and radiation patterns. The goal is to improve the estimation accuracy of the DOA compared to previous techniques that did not consider the directivity of conformal antenna elements.
This document presents a novel technique for fault detection and classification on double circuit transmission lines using artificial neural networks (ANNs). The technique uses high frequency transients caused by faults to identify internal and external faults. ANNs with suitable numbers of neurons are used to analyze voltage and current signals and decompose them to identify faults. Extensive simulation studies show the proposed approach can accurately discriminate between internal and external faults, providing fast, effective, and efficient protection. The document describes modeling a double circuit transmission line system in MATLAB, selecting ANN input/output parameters, developing a 3-layer 45-neuron ANN structure, and presenting simulation results demonstrating the ANN can detect and classify different fault types within a few milliseconds.
Amazon products reviews classification based on machine learning, deep learni...TELKOMNIKA JOURNAL
In recent times, the trend of online shopping through e-commerce stores and websites has grown to a huge extent. Whenever a product is purchased on an e-commerce platform, people leave their reviews about the product. These reviews are very helpful for the store owners and the product’s manufacturers for the betterment of their work process as well as product quality. An automated system is proposed in this work that operates on two datasets D1 and D2 obtained from Amazon. After certain preprocessing steps, N-gram and word embedding-based features are extracted using term frequency-inverse document frequency (TF-IDF), bag of words (BoW) and global vectors (GloVe), and Word2vec, respectively. Four machine learning (ML) models support vector machines (SVM), logistic regression (RF), logistic regression (LR), multinomial Naïve Bayes (MNB), two deep learning (DL) models convolutional neural network (CNN), long-short term memory (LSTM), and standalone bidirectional encoder representations (BERT) are used to classify reviews as either positive or negative. The results obtained by the standard ML, DL models and BERT are evaluated using certain performance evaluation measures. BERT turns out to be the best-performing model in the case of D1 with an accuracy of 90% on features derived by word embedding models while the CNN provides the best accuracy of 97% upon word embedding features in the case of D2. The proposed model shows better overall performance on D2 as compared to D1.
Design, simulation, and analysis of microstrip patch antenna for wireless app...TELKOMNIKA JOURNAL
In this study, a microstrip patch antenna that works at 3.6 GHz was built and tested to see how well it works. In this work, Rogers RT/Duroid 5880 has been used as the substrate material, with a dielectric permittivity of 2.2 and a thickness of 0.3451 mm; it serves as the base for the examined antenna. The computer simulation technology (CST) studio suite is utilized to show the recommended antenna design. The goal of this study was to get a more extensive transmission capacity, a lower voltage standing wave ratio (VSWR), and a lower return loss, but the main goal was to get a higher gain, directivity, and efficiency. After simulation, the return loss, gain, directivity, bandwidth, and efficiency of the supplied antenna are found to be -17.626 dB, 9.671 dBi, 9.924 dBi, 0.2 GHz, and 97.45%, respectively. Besides, the recreation uncovered that the transfer speed side-lobe level at phi was much better than those of the earlier works, at -28.8 dB, respectively. Thus, it makes a solid contender for remote innovation and more robust communication.
Fault Tolerant Matrix Pencil Method for Direction of Arrival Estimationsipij
Continuing to estimate the Direction-of-arrival (DOA) of the signals impinging on the antenna array, even when a few elements of the underlying Uniform Linear Antenna Array (ULA) fail to work will be of practical interest in RADAR, SONAR and Wireless Radio Communication Systems. This paper proposes a new technique to estimate the DOAs when a few elements are malfunctioning. The technique combines Singular Value Thresholding (SVT) based Matrix Completion (MC) procedure with the Direct Data Domain (D3) based Matrix Pencil (MP) Method. When the element failure is observed, first, the MC is performed to recover the missing data from failed elements, and then the MP method is used to estimate the DOAs. We also, propose a very simple technique to detect the location of elements failed, which is required to perform MC procedure. We provide simulation studies to demonstrate the performance and usefulness of the proposed technique. The results indicate a better performance, of the proposed DOA estimation scheme under different antenna failure scenarios.
This document summarizes research on using particle swarm optimization (PSO) to enhance the radiation pattern of a phase array antenna. It begins by introducing the problem of high sidelobes in phase array antenna patterns. It then provides background on phased array antennas and array pattern modeling. A 24-element linear array modeled in MATLAB is used as a case study. Standard PSO and a modified PSO algorithm are applied to optimize the current excitations and minimize the sidelobe levels. Simulation results show that both PSO approaches reduce sidelobes compared to uniform excitation, with the modified PSO performing better. Overall, the document presents research on using computational optimization methods to improve phase array antenna radiation patterns by controlling sidelobe levels
Enhancing the Radiation Pattern of Phase Array Antenna Using Particle Swarm O...IOSR Journals
The document describes a study that uses particle swarm optimization to enhance the radiation pattern of a phase array antenna by minimizing sidelobe levels. It first provides background on issues with high sidelobes in phase array antennas, such as power losses and interference. It then summarizes previous research using techniques like genetic algorithms for antenna array optimization. The study models the radiation pattern of linear arrays with different element numbers and calculates gain, finding that gain increases with more elements. However, sidelobe levels also increase relatively. Therefore, the study proposes using particle swarm optimization to optimize current excitation and control sidelobe levels while maintaining a narrow beamwidth.
performance analysis of MUSIC and ESPRIT DOA estimation used in adaptive arra...CSCJournals
MUSIC and ESPRIT DOA Estimaion algorithms are widely used in adaptive array to locate the desired desired signal.MUSIC is found to be more stable and accurate and widely used inthe design of adaptive array.
This document proposes an adaptive scheme for measuring signal parameters for generator monitoring and protection using adaptive orthogonal filters. The algorithm adapts the filter data window length and coefficients according to a coarse estimation of the signal frequency, allowing accurate measurements over a wide frequency band including during generator start-up. Measured signals are also used to train artificial neural networks to classify generator operation modes and detect phenomena like pole slipping and out-of-step conditions. The document describes the adaptive measurement scheme, provides an example using signals from simulations, and discusses using a genetic algorithm to optimize the design of an artificial neural network-based out-of-step protection system.
Simulation of an adaptive digital beamformer using matlabIJARBEST JOURNAL
Beam forming is the process of combining the weighted signals received on an array of
sensors to improve the directionality. Adaptive beamforming is the ability of the beamformer to
receive the signal only from the desired direction and to reject all other signals from undesired
directions. The weight vector for the adaptive beamformer continuously changes based on some
adaptive algorithm. Therefore, adaptive digital beam formers can point the antenna to the signal
direction without changing the physical architecture of the array antenna. The beam pointing
direction can be varied electronically with this technique. This paper focuses on Least Mean
Square (LMS) adaptive algorithm.
IRJET- Performance Evaluation of DOA Estimation using MUSIC and Beamformi...IRJET Journal
This document presents a simulation study comparing the MUSIC algorithm and LMS adaptive beamforming algorithm for direction of arrival (DOA) estimation and beamforming in a smart antenna system. The MUSIC algorithm uses eigendecomposition to estimate the DOA of multiple signals and finds the position location of the desired user. The LMS algorithm then adapts the beam pattern by adjusting weights to maximize gain towards the desired user while nulling interference from other directions. The simulation results show sharp peaks in the MUSIC spectrum to accurately locate the desired user and deep nulls in the LMS beam pattern to suppress interference.
Smart Antenna is a device with signal processing
capability combining multiple antenna elements to optimize its
radiation and reception patterns as per designed specifications.
Smart antennas basically comprise of two functionalities, i.e.,
Direction of Arrival and Beamforming. This paper explains the
estimation of Direction of Arrival using MLM method and a
novel approach called MUltiple Signal Classification which takes
advantage of orthogonal property and performs subspace
computation. With a comparative study of both the algorithms,
we shall prove the advantages of MUltiple Signal Classification
over the MLM method with the aid of MATLAB
Direction of Arrival Estimation Based on MUSIC Algorithm Using Uniform and No...IJERA Editor
In signal processing, the direction of arrival (DOA) estimation denotes the direction from which a propagating wave arrives at a point, where a set of antennas is located. Using the array antenna has an advantage over the single antenna in achieving an improved performance by applying Multiple Signal Classification (MUSIC) algorithm. This paper focuses on estimating the DOA using uniform linear array (ULA) and non-uniform linear array (NLA)of antennas to analyze the performance factors that affect the accuracy and resolution of the system based on MUSIC algorithm. The direction of arrival estimation is simulated on a MATLAB platform with a set of input parameters such as array elements, signal to noise ratio, number of snapshots and number of signal sources. An extensive simulation has been conducted and the results show that the NLA with DOA estimation for co-prime array can achieve an accurate and efficient DOA estimation
A Fault Detection and Classification Method for SC Transmission Line Using Ph...paperpublications3
Abstract: In this paper, fault detection and classification for Series Compensated Line (SCL) using phasor measurement unit is presented. The algorithm presented in this paper uses the PMU synchronized measurements and not depends on the data to be provided by the electricity utility. The compensated line parameters and Thevenin’s equivalent (TE) of the system at SCL terminals are calculated online, using three independent sets of pre-fault phasor measurements. The accuracy of fault location is performed with respect to fault location/position, types of fault, fault angle. The accuracy of the algorithm is simulated in MATLAB for 9-bus transmission system.
Signal processing with frequency and phase shift keying modulation in telecom...TELKOMNIKA JOURNAL
In this paper represents research improving effectiveness of signal processing in telecommunication devices especially for its part, which relates to providing its noise resistance in conditions of noise and interference. This objective has been achieved through development of methods and means for optimization of filtering devices and semigraphical interpretation of clock synchronization systems in telecommunications with frequency shift keying on the base of stochastic models what determines relevance of the subject. Separately, in an article considered the urgent task is using of modified synchronization methods based on the interference influence of adjacent symbols on the phase criterion tract, in particular the use of the modified synchronization scheme, in order to get a formalized outlook representation of the synchronization schemas based on the polyphase structures with using a bank of filters, that allows to improve the characteristics of digital telecommunication channels. This work is devoted to the examination and modeling of these ways. The proposed ideas and results for the construction of synchronization systems can be used in modern means of telecommunication.
A Survey on Applications of Neural Networks and Genetic Algorithms in Fault D...IOSR Journals
This document summarizes research on using neural networks and genetic algorithms for fault diagnosis in antenna arrays. It provides background on smart antenna arrays and issues with traditional fault diagnosis methods. It then describes how neural networks like multilayer perceptrons and radial basis function networks can be trained to map damaged radiation patterns to faulty antenna locations. Genetic algorithms are also discussed as an approach to minimize differences between measured and expected radiation patterns. Various studies applying these methods to different antenna array configurations are summarized, demonstrating the effectiveness of neural networks and genetic algorithms for fast and accurate fault diagnosis in antenna arrays.
The document describes a hybrid method for simultaneously calculating the resonant frequencies of rectangular, circular, and triangular microstrip antennas (MSAs). The hybrid method combines an artificial neural network (ANN) and fuzzy inference system (FIS). The ANN is first used to compute resonant frequencies, and the fuzzy inference system corrects any inaccuracies in the ANN computations. The hybrid method allows for a single model to calculate resonant frequencies across different antenna geometries simultaneously. Results from the hybrid method show very good agreement with experimental data in the literature, improving upon results from previous single neural network models.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Array diagnosis using compressed sensing in near fieldAlexander Decker
This document summarizes a technique for diagnosing faults in antenna arrays using compressed sensing on near-field measurement data. The technique aims to reduce measurement time by acquiring data from fewer measurement points compared to traditional methods like back-propagation. It does this by taking the difference between near-field measurements of a reference array without faults and the array under test to create a sparse "innovation vector". This vector is then reconstructed using an L1-norm regularization technique from compressed sensing. Numerical examples on a 289-element array show the technique can accurately detect up to 3 faulty elements from a small number of measurement points on the order of KlogN, where K is the number of faults.
Assessment of quality indicators of the automatic control system influence of...TELKOMNIKA JOURNAL
This work concentrates the analysis of the system of automatic control of the directive diagram of the moving active electronically scanned array with a limited number of transceiver modules. The analysis revealed a number of shortcomings that lead to a significant increase in standard deviations, quadratic integral estimates, and an increase in transient time. The identified disadvantages lead to a decrease in the efficiency of the antenna system, an increase in the error rate at the reception, the inability of the system to react to disturbances applied to any point of the system in the event of a mismatch of a given signal/noise level. In accordance with the analysis, the mathematical model of the automatic control system of the directional diagram of the moving active electronically scanned array was considered, considering this a new method of estimating the quality indicators of the automatic control diagram of the directional diagram of the active electronically scanned array in a random setting and disturbing action was developed. The difference between the proposed method and the existing method is in the construction of an automatic control system with differential coupling equivalent to the combination due to the introduction of derivatives of the random setting action of the open compensation connection.
This document analyzes and compares the performance of different adaptive beamforming techniques for smart antennas. It describes switched beamforming, which uses fixed beams, and adaptive beamforming techniques that use algorithms like LMS, SMI, RLS, CGA, CMA, and LSCMA to form an adaptive beam. It simulates these algorithms using MATLAB for a uniform linear array and compares their ability to direct the main beam towards the desired user while nulling interference. The LMS, SMI, RLS, CMA and LSCMA algorithms are found to perform well at directing the beam to the desired user, with LMS having good interference rejection and RLS providing the fastest convergence but highest computational cost.
This document describes a study on estimating the direction of arrival (DOA) of signals using a conformal antenna array and the MUSIC algorithm. A seven-element conformal antenna array is designed using microstrip patch antennas mounted on a truncated hexagonal pyramid structure. The MUSIC algorithm is derived for this conformal antenna array to estimate the DOA. Simulation software will be used to analyze the antenna array's performance parameters like bandwidth, return loss, gain, and radiation patterns. The goal is to improve the estimation accuracy of the DOA compared to previous techniques that did not consider the directivity of conformal antenna elements.
This document presents a novel technique for fault detection and classification on double circuit transmission lines using artificial neural networks (ANNs). The technique uses high frequency transients caused by faults to identify internal and external faults. ANNs with suitable numbers of neurons are used to analyze voltage and current signals and decompose them to identify faults. Extensive simulation studies show the proposed approach can accurately discriminate between internal and external faults, providing fast, effective, and efficient protection. The document describes modeling a double circuit transmission line system in MATLAB, selecting ANN input/output parameters, developing a 3-layer 45-neuron ANN structure, and presenting simulation results demonstrating the ANN can detect and classify different fault types within a few milliseconds.
Amazon products reviews classification based on machine learning, deep learni...TELKOMNIKA JOURNAL
In recent times, the trend of online shopping through e-commerce stores and websites has grown to a huge extent. Whenever a product is purchased on an e-commerce platform, people leave their reviews about the product. These reviews are very helpful for the store owners and the product’s manufacturers for the betterment of their work process as well as product quality. An automated system is proposed in this work that operates on two datasets D1 and D2 obtained from Amazon. After certain preprocessing steps, N-gram and word embedding-based features are extracted using term frequency-inverse document frequency (TF-IDF), bag of words (BoW) and global vectors (GloVe), and Word2vec, respectively. Four machine learning (ML) models support vector machines (SVM), logistic regression (RF), logistic regression (LR), multinomial Naïve Bayes (MNB), two deep learning (DL) models convolutional neural network (CNN), long-short term memory (LSTM), and standalone bidirectional encoder representations (BERT) are used to classify reviews as either positive or negative. The results obtained by the standard ML, DL models and BERT are evaluated using certain performance evaluation measures. BERT turns out to be the best-performing model in the case of D1 with an accuracy of 90% on features derived by word embedding models while the CNN provides the best accuracy of 97% upon word embedding features in the case of D2. The proposed model shows better overall performance on D2 as compared to D1.
Design, simulation, and analysis of microstrip patch antenna for wireless app...TELKOMNIKA JOURNAL
In this study, a microstrip patch antenna that works at 3.6 GHz was built and tested to see how well it works. In this work, Rogers RT/Duroid 5880 has been used as the substrate material, with a dielectric permittivity of 2.2 and a thickness of 0.3451 mm; it serves as the base for the examined antenna. The computer simulation technology (CST) studio suite is utilized to show the recommended antenna design. The goal of this study was to get a more extensive transmission capacity, a lower voltage standing wave ratio (VSWR), and a lower return loss, but the main goal was to get a higher gain, directivity, and efficiency. After simulation, the return loss, gain, directivity, bandwidth, and efficiency of the supplied antenna are found to be -17.626 dB, 9.671 dBi, 9.924 dBi, 0.2 GHz, and 97.45%, respectively. Besides, the recreation uncovered that the transfer speed side-lobe level at phi was much better than those of the earlier works, at -28.8 dB, respectively. Thus, it makes a solid contender for remote innovation and more robust communication.
Design and simulation an optimal enhanced PI controller for congestion avoida...TELKOMNIKA JOURNAL
This document describes using a snake optimization algorithm to tune the gains of an enhanced proportional-integral controller for congestion avoidance in a TCP/AQM system. The controller aims to maintain a stable and desired queue size without noise or transmission problems. A linearized model of the TCP/AQM system is presented. An enhanced PI controller combining nonlinear gain and original PI gains is proposed. The snake optimization algorithm is then used to tune the parameters of the enhanced PI controller to achieve optimal system performance and response. Simulation results are discussed showing the proposed controller provides a stable and robust behavior for congestion control.
Improving the detection of intrusion in vehicular ad-hoc networks with modifi...TELKOMNIKA JOURNAL
Vehicular ad-hoc networks (VANETs) are wireless-equipped vehicles that form networks along the road. The security of this network has been a major challenge. The identity-based cryptosystem (IBC) previously used to secure the networks suffers from membership authentication security features. This paper focuses on improving the detection of intruders in VANETs with a modified identity-based cryptosystem (MIBC). The MIBC is developed using a non-singular elliptic curve with Lagrange interpolation. The public key of vehicles and roadside units on the network are derived from number plates and location identification numbers, respectively. Pseudo-identities are used to mask the real identity of users to preserve their privacy. The membership authentication mechanism ensures that only valid and authenticated members of the network are allowed to join the network. The performance of the MIBC is evaluated using intrusion detection ratio (IDR) and computation time (CT) and then validated with the existing IBC. The result obtained shows that the MIBC recorded an IDR of 99.3% against 94.3% obtained for the existing identity-based cryptosystem (EIBC) for 140 unregistered vehicles attempting to intrude on the network. The MIBC shows lower CT values of 1.17 ms against 1.70 ms for EIBC. The MIBC can be used to improve the security of VANETs.
Conceptual model of internet banking adoption with perceived risk and trust f...TELKOMNIKA JOURNAL
Understanding the primary factors of internet banking (IB) acceptance is critical for both banks and users; nevertheless, our knowledge of the role of users’ perceived risk and trust in IB adoption is limited. As a result, we develop a conceptual model by incorporating perceived risk and trust into the technology acceptance model (TAM) theory toward the IB. The proper research emphasized that the most essential component in explaining IB adoption behavior is behavioral intention to use IB adoption. TAM is helpful for figuring out how elements that affect IB adoption are connected to one another. According to previous literature on IB and the use of such technology in Iraq, one has to choose a theoretical foundation that may justify the acceptance of IB from the customer’s perspective. The conceptual model was therefore constructed using the TAM as a foundation. Furthermore, perceived risk and trust were added to the TAM dimensions as external factors. The key objective of this work was to extend the TAM to construct a conceptual model for IB adoption and to get sufficient theoretical support from the existing literature for the essential elements and their relationships in order to unearth new insights about factors responsible for IB adoption.
Efficient combined fuzzy logic and LMS algorithm for smart antennaTELKOMNIKA JOURNAL
The smart antennas are broadly used in wireless communication. The least mean square (LMS) algorithm is a procedure that is concerned in controlling the smart antenna pattern to accommodate specified requirements such as steering the beam toward the desired signal, in addition to placing the deep nulls in the direction of unwanted signals. The conventional LMS (C-LMS) has some drawbacks like slow convergence speed besides high steady state fluctuation error. To overcome these shortcomings, the present paper adopts an adaptive fuzzy control step size least mean square (FC-LMS) algorithm to adjust its step size. Computer simulation outcomes illustrate that the given model has fast convergence rate as well as low mean square error steady state.
Design and implementation of a LoRa-based system for warning of forest fireTELKOMNIKA JOURNAL
This paper presents the design and implementation of a forest fire monitoring and warning system based on long range (LoRa) technology, a novel ultra-low power consumption and long-range wireless communication technology for remote sensing applications. The proposed system includes a wireless sensor network that records environmental parameters such as temperature, humidity, wind speed, and carbon dioxide (CO2) concentration in the air, as well as taking infrared photos.The data collected at each sensor node will be transmitted to the gateway via LoRa wireless transmission. Data will be collected, processed, and uploaded to a cloud database at the gateway. An Android smartphone application that allows anyone to easily view the recorded data has been developed. When a fire is detected, the system will sound a siren and send a warning message to the responsible personnel, instructing them to take appropriate action. Experiments in Tram Chim Park, Vietnam, have been conducted to verify and evaluate the operation of the system.
Wavelet-based sensing technique in cognitive radio networkTELKOMNIKA JOURNAL
Cognitive radio is a smart radio that can change its transmitter parameter based on interaction with the environment in which it operates. The demand for frequency spectrum is growing due to a big data issue as many Internet of Things (IoT) devices are in the network. Based on previous research, most frequency spectrum was used, but some spectrums were not used, called spectrum hole. Energy detection is one of the spectrum sensing methods that has been frequently used since it is easy to use and does not require license users to have any prior signal understanding. But this technique is incapable of detecting at low signal-to-noise ratio (SNR) levels. Therefore, the wavelet-based sensing is proposed to overcome this issue and detect spectrum holes. The main objective of this work is to evaluate the performance of wavelet-based sensing and compare it with the energy detection technique. The findings show that the percentage of detection in wavelet-based sensing is 83% higher than energy detection performance. This result indicates that the wavelet-based sensing has higher precision in detection and the interference towards primary user can be decreased.
A novel compact dual-band bandstop filter with enhanced rejection bandsTELKOMNIKA JOURNAL
In this paper, we present the design of a new wide dual-band bandstop filter (DBBSF) using nonuniform transmission lines. The method used to design this filter is to replace conventional uniform transmission lines with nonuniform lines governed by a truncated Fourier series. Based on how impedances are profiled in the proposed DBBSF structure, the fractional bandwidths of the two 10 dB-down rejection bands are widened to 39.72% and 52.63%, respectively, and the physical size has been reduced compared to that of the filter with the uniform transmission lines. The results of the electromagnetic (EM) simulation support the obtained analytical response and show an improved frequency behavior.
Deep learning approach to DDoS attack with imbalanced data at the application...TELKOMNIKA JOURNAL
A distributed denial of service (DDoS) attack is where one or more computers attack or target a server computer, by flooding internet traffic to the server. As a result, the server cannot be accessed by legitimate users. A result of this attack causes enormous losses for a company because it can reduce the level of user trust, and reduce the company’s reputation to lose customers due to downtime. One of the services at the application layer that can be accessed by users is a web-based lightweight directory access protocol (LDAP) service that can provide safe and easy services to access directory applications. We used a deep learning approach to detect DDoS attacks on the CICDDoS 2019 dataset on a complex computer network at the application layer to get fast and accurate results for dealing with unbalanced data. Based on the results obtained, it is observed that DDoS attack detection using a deep learning approach on imbalanced data performs better when implemented using synthetic minority oversampling technique (SMOTE) method for binary classes. On the other hand, the proposed deep learning approach performs better for detecting DDoS attacks in multiclass when implemented using the adaptive synthetic (ADASYN) method.
The appearance of uncertainties and disturbances often effects the characteristics of either linear or nonlinear systems. Plus, the stabilization process may be deteriorated thus incurring a catastrophic effect to the system performance. As such, this manuscript addresses the concept of matching condition for the systems that are suffering from miss-match uncertainties and exogeneous disturbances. The perturbation towards the system at hand is assumed to be known and unbounded. To reach this outcome, uncertainties and their classifications are reviewed thoroughly. The structural matching condition is proposed and tabulated in the proposition 1. Two types of mathematical expressions are presented to distinguish the system with matched uncertainty and the system with miss-matched uncertainty. Lastly, two-dimensional numerical expressions are provided to practice the proposed proposition. The outcome shows that matching condition has the ability to change the system to a design-friendly model for asymptotic stabilization.
Implementation of FinFET technology based low power 4×4 Wallace tree multipli...TELKOMNIKA JOURNAL
Many systems, including digital signal processors, finite impulse response (FIR) filters, application-specific integrated circuits, and microprocessors, use multipliers. The demand for low power multipliers is gradually rising day by day in the current technological trend. In this study, we describe a 4×4 Wallace multiplier based on a carry select adder (CSA) that uses less power and has a better power delay product than existing multipliers. HSPICE tool at 16 nm technology is used to simulate the results. In comparison to the traditional CSA-based multiplier, which has a power consumption of 1.7 µW and power delay product (PDP) of 57.3 fJ, the results demonstrate that the Wallace multiplier design employing CSA with first zero finding logic (FZF) logic has the lowest power consumption of 1.4 µW and PDP of 27.5 fJ.
Evaluation of the weighted-overlap add model with massive MIMO in a 5G systemTELKOMNIKA JOURNAL
The flaw in 5G orthogonal frequency division multiplexing (OFDM) becomes apparent in high-speed situations. Because the doppler effect causes frequency shifts, the orthogonality of OFDM subcarriers is broken, lowering both their bit error rate (BER) and throughput output. As part of this research, we use a novel design that combines massive multiple input multiple output (MIMO) and weighted overlap and add (WOLA) to improve the performance of 5G systems. To determine which design is superior, throughput and BER are calculated for both the proposed design and OFDM. The results of the improved system show a massive improvement in performance ver the conventional system and significant improvements with massive MIMO, including the best throughput and BER. When compared to conventional systems, the improved system has a throughput that is around 22% higher and the best performance in terms of BER, but it still has around 25% less error than OFDM.
Reflector antenna design in different frequencies using frequency selective s...TELKOMNIKA JOURNAL
In this study, it is aimed to obtain two different asymmetric radiation patterns obtained from antennas in the shape of the cross-section of a parabolic reflector (fan blade type antennas) and antennas with cosecant-square radiation characteristics at two different frequencies from a single antenna. For this purpose, firstly, a fan blade type antenna design will be made, and then the reflective surface of this antenna will be completed to the shape of the reflective surface of the antenna with the cosecant-square radiation characteristic with the frequency selective surface designed to provide the characteristics suitable for the purpose. The frequency selective surface designed and it provides the perfect transmission as possible at 4 GHz operating frequency, while it will act as a band-quenching filter for electromagnetic waves at 5 GHz operating frequency and will be a reflective surface. Thanks to this frequency selective surface to be used as a reflective surface in the antenna, a fan blade type radiation characteristic at 4 GHz operating frequency will be obtained, while a cosecant-square radiation characteristic at 5 GHz operating frequency will be obtained.
Reagentless iron detection in water based on unclad fiber optical sensorTELKOMNIKA JOURNAL
A simple and low-cost fiber based optical sensor for iron detection is demonstrated in this paper. The sensor head consist of an unclad optical fiber with the unclad length of 1 cm and it has a straight structure. Results obtained shows a linear relationship between the output light intensity and iron concentration, illustrating the functionality of this iron optical sensor. Based on the experimental results, the sensitivity and linearity are achieved at 0.0328/ppm and 0.9824 respectively at the wavelength of 690 nm. With the same wavelength, other performance parameters are also studied. Resolution and limit of detection (LOD) are found to be 0.3049 ppm and 0.0755 ppm correspondingly. This iron sensor is advantageous in that it does not require any reagent for detection, enabling it to be simpler and cost-effective in the implementation of the iron sensing.
Impact of CuS counter electrode calcination temperature on quantum dot sensit...TELKOMNIKA JOURNAL
In place of the commercial Pt electrode used in quantum sensitized solar cells, the low-cost CuS cathode is created using electrophoresis. High resolution scanning electron microscopy and X-ray diffraction were used to analyze the structure and morphology of structural cubic samples with diameters ranging from 40 nm to 200 nm. The conversion efficiency of solar cells is significantly impacted by the calcination temperatures of cathodes at 100 °C, 120 °C, 150 °C, and 180 °C under vacuum. The fluorine doped tin oxide (FTO)/CuS cathode electrode reached a maximum efficiency of 3.89% when it was calcined at 120 °C. Compared to other temperature combinations, CuS nanoparticles crystallize at 120 °C, which lowers resistance while increasing electron lifetime.
In place of the commercial Pt electrode used in quantum sensitized solar cells, the low-cost CuS cathode is created using electrophoresis. High resolution scanning electron microscopy and X-ray diffraction were used to analyze the structure and morphology of structural cubic samples with diameters ranging from 40 nm to 200 nm. The conversion efficiency of solar cells is significantly impacted by the calcination temperatures of cathodes at 100 °C, 120 °C, 150 °C, and 180 °C under vacuum. The fluorine doped tin oxide (FTO)/CuS cathode electrode reached a maximum efficiency of 3.89% when it was calcined at 120 °C. Compared to other temperature combinations, CuS nanoparticles crystallize at 120 °C, which lowers resistance while increasing electron lifetime.
A progressive learning for structural tolerance online sequential extreme lea...TELKOMNIKA JOURNAL
This article discusses the progressive learning for structural tolerance online sequential extreme learning machine (PSTOS-ELM). PSTOS-ELM can save robust accuracy while updating the new data and the new class data on the online training situation. The robustness accuracy arises from using the householder block exact QR decomposition recursive least squares (HBQRD-RLS) of the PSTOS-ELM. This method is suitable for applications that have data streaming and often have new class data. Our experiment compares the PSTOS-ELM accuracy and accuracy robustness while data is updating with the batch-extreme learning machine (ELM) and structural tolerance online sequential extreme learning machine (STOS-ELM) that both must retrain the data in a new class data case. The experimental results show that PSTOS-ELM has accuracy and robustness comparable to ELM and STOS-ELM while also can update new class data immediately.
Electroencephalography-based brain-computer interface using neural networksTELKOMNIKA JOURNAL
This study aimed to develop a brain-computer interface that can control an electric wheelchair using electroencephalography (EEG) signals. First, we used the Mind Wave Mobile 2 device to capture raw EEG signals from the surface of the scalp. The signals were transformed into the frequency domain using fast Fourier transform (FFT) and filtered to monitor changes in attention and relaxation. Next, we performed time and frequency domain analyses to identify features for five eye gestures: opened, closed, blink per second, double blink, and lookup. The base state was the opened-eyes gesture, and we compared the features of the remaining four action gestures to the base state to identify potential gestures. We then built a multilayer neural network to classify these features into five signals that control the wheelchair’s movement. Finally, we designed an experimental wheelchair system to test the effectiveness of the proposed approach. The results demonstrate that the EEG classification was highly accurate and computationally efficient. Moreover, the average performance of the brain-controlled wheelchair system was over 75% across different individuals, which suggests the feasibility of this approach.
Adaptive segmentation algorithm based on level set model in medical imagingTELKOMNIKA JOURNAL
For image segmentation, level set models are frequently employed. It offer best solution to overcome the main limitations of deformable parametric models. However, the challenge when applying those models in medical images stills deal with removing blurs in image edges which directly affects the edge indicator function, leads to not adaptively segmenting images and causes a wrong analysis of pathologies wich prevents to conclude a correct diagnosis. To overcome such issues, an effective process is suggested by simultaneously modelling and solving systems’ two-dimensional partial differential equations (PDE). The first PDE equation allows restoration using Euler’s equation similar to an anisotropic smoothing based on a regularized Perona and Malik filter that eliminates noise while preserving edge information in accordance with detected contours in the second equation that segments the image based on the first equation solutions. This approach allows developing a new algorithm which overcome the studied model drawbacks. Results of the proposed method give clear segments that can be applied to any application. Experiments on many medical images in particular blurry images with high information losses, demonstrate that the developed approach produces superior segmentation results in terms of quantity and quality compared to other models already presented in previeous works.
Automatic channel selection using shuffled frog leaping algorithm for EEG bas...TELKOMNIKA JOURNAL
Drug addiction is a complex neurobiological disorder that necessitates comprehensive treatment of both the body and mind. It is categorized as a brain disorder due to its impact on the brain. Various methods such as electroencephalography (EEG), functional magnetic resonance imaging (FMRI), and magnetoencephalography (MEG) can capture brain activities and structures. EEG signals provide valuable insights into neurological disorders, including drug addiction. Accurate classification of drug addiction from EEG signals relies on appropriate features and channel selection. Choosing the right EEG channels is essential to reduce computational costs and mitigate the risk of overfitting associated with using all available channels. To address the challenge of optimal channel selection in addiction detection from EEG signals, this work employs the shuffled frog leaping algorithm (SFLA). SFLA facilitates the selection of appropriate channels, leading to improved accuracy. Wavelet features extracted from the selected input channel signals are then analyzed using various machine learning classifiers to detect addiction. Experimental results indicate that after selecting features from the appropriate channels, classification accuracy significantly increased across all classifiers. Particularly, the multi-layer perceptron (MLP) classifier combined with SFLA demonstrated a remarkable accuracy improvement of 15.78% while reducing time complexity.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
Applications of artificial Intelligence in Mechanical Engineering.pdfAtif Razi
Historically, mechanical engineering has relied heavily on human expertise and empirical methods to solve complex problems. With the introduction of computer-aided design (CAD) and finite element analysis (FEA), the field took its first steps towards digitization. These tools allowed engineers to simulate and analyze mechanical systems with greater accuracy and efficiency. However, the sheer volume of data generated by modern engineering systems and the increasing complexity of these systems have necessitated more advanced analytical tools, paving the way for AI.
AI offers the capability to process vast amounts of data, identify patterns, and make predictions with a level of speed and accuracy unattainable by traditional methods. This has profound implications for mechanical engineering, enabling more efficient design processes, predictive maintenance strategies, and optimized manufacturing operations. AI-driven tools can learn from historical data, adapt to new information, and continuously improve their performance, making them invaluable in tackling the multifaceted challenges of modern mechanical engineering.
Advanced control scheme of doubly fed induction generator for wind turbine us...IJECEIAES
This paper describes a speed control device for generating electrical energy on an electricity network based on the doubly fed induction generator (DFIG) used for wind power conversion systems. At first, a double-fed induction generator model was constructed. A control law is formulated to govern the flow of energy between the stator of a DFIG and the energy network using three types of controllers: proportional integral (PI), sliding mode controller (SMC) and second order sliding mode controller (SOSMC). Their different results in terms of power reference tracking, reaction to unexpected speed fluctuations, sensitivity to perturbations, and resilience against machine parameter alterations are compared. MATLAB/Simulink was used to conduct the simulations for the preceding study. Multiple simulations have shown very satisfying results, and the investigations demonstrate the efficacy and power-enhancing capabilities of the suggested control system.
Prediction of Electrical Energy Efficiency Using Information on Consumer's Ac...PriyankaKilaniya
Energy efficiency has been important since the latter part of the last century. The main object of this survey is to determine the energy efficiency knowledge among consumers. Two separate districts in Bangladesh are selected to conduct the survey on households and showrooms about the energy and seller also. The survey uses the data to find some regression equations from which it is easy to predict energy efficiency knowledge. The data is analyzed and calculated based on five important criteria. The initial target was to find some factors that help predict a person's energy efficiency knowledge. From the survey, it is found that the energy efficiency awareness among the people of our country is very low. Relationships between household energy use behaviors are estimated using a unique dataset of about 40 households and 20 showrooms in Bangladesh's Chapainawabganj and Bagerhat districts. Knowledge of energy consumption and energy efficiency technology options is found to be associated with household use of energy conservation practices. Household characteristics also influence household energy use behavior. Younger household cohorts are more likely to adopt energy-efficient technologies and energy conservation practices and place primary importance on energy saving for environmental reasons. Education also influences attitudes toward energy conservation in Bangladesh. Low-education households indicate they primarily save electricity for the environment while high-education households indicate they are motivated by environmental concerns.
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
Software Engineering and Project Management - Software Testing + Agile Method...Prakhyath Rai
Software Testing: A Strategic Approach to Software Testing, Strategic Issues, Test Strategies for Conventional Software, Test Strategies for Object -Oriented Software, Validation Testing, System Testing, The Art of Debugging.
Agile Methodology: Before Agile – Waterfall, Agile Development.
Discover the latest insights on Data Driven Maintenance with our comprehensive webinar presentation. Learn about traditional maintenance challenges, the right approach to utilizing data, and the benefits of adopting a Data Driven Maintenance strategy. Explore real-world examples, industry best practices, and innovative solutions like FMECA and the D3M model. This presentation, led by expert Jules Oudmans, is essential for asset owners looking to optimize their maintenance processes and leverage digital technologies for improved efficiency and performance. Download now to stay ahead in the evolving maintenance landscape.
Generative AI Use cases applications solutions and implementation.pdfmahaffeycheryld
Generative AI solutions encompass a range of capabilities from content creation to complex problem-solving across industries. Implementing generative AI involves identifying specific business needs, developing tailored AI models using techniques like GANs and VAEs, and integrating these models into existing workflows. Data quality and continuous model refinement are crucial for effective implementation. Businesses must also consider ethical implications and ensure transparency in AI decision-making. Generative AI's implementation aims to enhance efficiency, creativity, and innovation by leveraging autonomous generation and sophisticated learning algorithms to meet diverse business challenges.
https://www.leewayhertz.com/generative-ai-use-cases-and-applications/
Design and optimization of ion propulsion dronebjmsejournal
Electric propulsion technology is widely used in many kinds of vehicles in recent years, and aircrafts are no exception. Technically, UAVs are electrically propelled but tend to produce a significant amount of noise and vibrations. Ion propulsion technology for drones is a potential solution to this problem. Ion propulsion technology is proven to be feasible in the earth’s atmosphere. The study presented in this article shows the design of EHD thrusters and power supply for ion propulsion drones along with performance optimization of high-voltage power supply for endurance in earth’s atmosphere.
Use PyCharm for remote debugging of WSL on a Windo cf5c162d672e4e58b4dde5d797...shadow0702a
This document serves as a comprehensive step-by-step guide on how to effectively use PyCharm for remote debugging of the Windows Subsystem for Linux (WSL) on a local Windows machine. It meticulously outlines several critical steps in the process, starting with the crucial task of enabling permissions, followed by the installation and configuration of WSL.
The guide then proceeds to explain how to set up the SSH service within the WSL environment, an integral part of the process. Alongside this, it also provides detailed instructions on how to modify the inbound rules of the Windows firewall to facilitate the process, ensuring that there are no connectivity issues that could potentially hinder the debugging process.
The document further emphasizes on the importance of checking the connection between the Windows and WSL environments, providing instructions on how to ensure that the connection is optimal and ready for remote debugging.
It also offers an in-depth guide on how to configure the WSL interpreter and files within the PyCharm environment. This is essential for ensuring that the debugging process is set up correctly and that the program can be run effectively within the WSL terminal.
Additionally, the document provides guidance on how to set up breakpoints for debugging, a fundamental aspect of the debugging process which allows the developer to stop the execution of their code at certain points and inspect their program at those stages.
Finally, the document concludes by providing a link to a reference blog. This blog offers additional information and guidance on configuring the remote Python interpreter in PyCharm, providing the reader with a well-rounded understanding of the process.
Use PyCharm for remote debugging of WSL on a Windo cf5c162d672e4e58b4dde5d797...
22. 23767.pdf
1. TELKOMNIKA Telecommunication Computing Electronics and Control
Vol. 20, No. 4, August 2022, pp. 892~900
ISSN: 1693-6930, DOI: 10.12928/TELKOMNIKA.v20i4.23767 892
Journal homepage: http://telkomnika.uad.ac.id
A compressed sensing approach for antenna array calibration
Akinwale Oluwaseyi Fadamiro1
, Fujiang Lin2
1
Department of Computer Engineering, School of Engineering and Engineering Technology, Federal University of Technology Akure,
Akure, Nigeria
2
Department of Electronic Science and Technology, School of Microelectronics, University of Science and Technology China,
Hefei, China
Article Info ABSTRACT
Article history:
Received Sep 23, 2021
Revised Apr 20, 2022
Accepted May 01, 2022
This paper presented a compressive sensing (CS) calibration technique that
simultaneously measures all the element excitations of a 2×2 active phased
antenna array (APAA) instantaneously. The power patterns of the
rectangular 2×2 APAA element are synchronized to orthogonally cross
multiplicative sub-array system applying compressive sensing in achieving
an array thinning along two 1-D sub-arrays for a fixed steered beam
radiation. The far field radiation pattern direction of the 2×2 APAA is
examined considering the mutual effect, complex excitation of the amplitude
and phase of the antenna elements placed on the x and y axes. The unwanted
array excitation with errors are calibrated using minimization vector as a
standard basic pursuit problem in compressive sensing technique for the 2×2
APAA calibration. The elements amplitude and phase shift variation are
compared with reference state 0 in order to evaluate the faulty error array
elements. The performance evaluation of this proposed technique is
measured and demonstrated to validate the effectiveness of the proposed
antenna calibration technique.
Keywords:
Antenna arrays
Antenna measurements
Calibration
Compressed sensing
Fault diagnosis
This is an open access article under the CC BY-SA license.
Corresponding Author:
Akinwale Oluwaseyi Fadamiro
Department of Computer Engineering, School of Engineering and Engineering Technology
Federal University of Technology Akure, Akure, Nigeria
Email: aofadamiro@futa.edu.ng
1. INTRODUCTION
Now adays, identification of failures in antenna array systems is theoretically and practically studied
for efficient signal propagation in radar communications, satellite, massive multiple-input and multiple-output
(MIMO), wireless communications and military applications [1]. Various advanced technologies have been
developed and investigated over the past few years that have the potential to increase the capacity of a
wireless communications system. In order to solve the problem of defficent elements in an antenna array
system, many approaches have been proposed in literatures including; back propagation technique, matrix
technique, neural networks, case based reasoning, genetic algorithms, source reconstruction technique and
signal processing based algorithm [2]-[9].
Compressive sensing has been applied in various approaches to failures in some elements in an arrays
under test (AUTs) to detect the faulty elements in a phased or active array system [10]-[14]. To resolve such a
problem, initial knowledge of the failure-free antenna array radiation pattern, amplitude, and phase is required
and it is referred to as reference state or state 0, in examining the faulty array elements [15]. Hence, a fast
testing, diagnosis, and calibration of antenna array systems are essential.
Calibration starts with adequate analysis of uncertainties to define the error tolerance, selection of
the appropriate calibration, and measurement technique. Considering the AUT, error factors can be classified
as dynamic errors with time difference, amplitude, phase shift variation and static errors which includes the
2. TELKOMNIKA Telecommun Comput El Control
A compressed sensing approach for antenna array calibration (Akinwale Oluwaseyi Fadamiro)
893
manufacturing tolerances of the antenna array system [16]. Considering the categorization of the calibration
process, an on-site calibration procedure is mostly implemented to compensate the error influence of the site
or to update the coefficients because of the frequency change for transmission.
Calibration is important in deriving an adequate antenna array propagation performance by
compensating the errors in the system. Generally, there are two classes of calibration techniques namely;
single element and multiple elements measurement techniques [17]. Therefore, different approaches have
been applied in literature which includes; the phase toggling technique [14], rotating element electric field
vector (REV) technique [18] and four orthogonal phase states technique [19]. A recursive matrix-forming
approach for the matrix selection of a multi-element phased array calibration [17], and a modified matrix
technique for phased array calibration by resolving the linear equations are investigated in this paper [20],
phase-encoding matrix modified from the finite phase-encoding setting accuracy for active phased-array
antennas for synthetic aperture radar (SAR) [21], fast Fourier transform (FFT) and harmonic characteristic
analysis for parallel calibration of phased array [22], and Fourier coefficients of one array-power response
measured with the conventional rotating element electric field vector (REV) technique [23].
Recently, compressive sensing (CS) theory is evolving in solving linear equations relating to array
diagnosis for evaluating the amplitude and phase of a near and far field measurements [11]-[13].
Consequently, a compressive sensing approach is being applied to detect faulty radiators in planar antenna
arrays using a reduced set of phaseless far-field measurements, demonstrating that the nonlinear problem can
be solved as long as the percentage of faulty elements is low and a smart measurement strategy is used.
Numerical simulations and experimental results, have confirmed the good performance of the CS technique
in terms of probability of fault detection [24].
In this paper, 𝑙1 compressive sensing technique is applied to diagnosis and calibrate a faulty error
elements in 2D active phased array antenna (APAA) system. The faulty antenna element errors in the APAA
casues a slight amplitude and phase shift variation which will be calibrated with a reference state 0 to
evaluate the faulty elements. The unwanted array excitation with errors are calibrated using minimization
vector (w) as a standard basic pursuit problem in compressive sensing approach for the 2×2 APAA
calibration. In the following section, the research theory is presented in section 2, the methodology is presented
in section 3, results and discussions is presented in section 4 and the conclusion follows in section 5.
2. THEORY
A 2D APAA with dimension 𝑃 × 𝑄 AUT elements is uniformly distributed in a square equispaced
grid of the 𝑝𝑥 elements in the 𝑥 axis and 𝑞𝑦 elements on the 𝑦 axis. To avoid grating lobes and high side
lobes, 𝑟𝑥 and 𝑟𝑦 should be ≤ λ/2. The array factor (𝛼) of the isotropic APAA is described in the (1) as:
∝ (∅ , ϕ) = ∑ 𝐴𝑝𝑥 𝑒𝑗(𝑝
2𝜋𝑟𝑥
𝑥
𝑠𝑖𝑛𝜃𝑐𝑜𝑠ϕ+𝐷𝑝𝑥)
𝑃−1
𝑃=0 ∑ 𝐴𝑞𝑥𝑒𝑗(𝑞
2𝜋𝑟𝑦
𝑥
𝑠𝑖𝑛𝜃𝑐𝑜𝑠𝜙+𝐷𝑝𝑦)
𝑄−1
𝑄=0 (1)
𝐴𝑝𝑥 = antenna element amplitude excitation along the 𝑥 axis
𝐴𝑞𝑦 = antenna element amplitude excitation along the 𝑦 axis
𝐷𝑝𝑥 = antenna element phase shift along the 𝑥 axis
𝐷𝑞𝑦 = antenna element phase shift along the 𝑦 axis
𝑟𝑥 = spacing between 𝑝𝑥 elements along the 𝑥 axis
𝑟𝑦 = spacing between 𝑞𝑦 elements along the 𝑦 axis
∝ (∅ , ϕ) = 𝑃𝑥𝑄𝑦 ∑ ∑ ∑ 𝐴𝑝𝑥𝑒
−𝑗(𝑃(ℎ𝑥−ℎ𝑥𝑖)𝑟𝑥𝑠𝑖𝑛𝜃𝑐𝑜𝑠𝜙+𝐷𝑝𝑥)
𝑥
𝑝𝑥
𝐴2𝑦
𝑒−𝑗(2(ℎ𝑦−ℎ𝑦𝑖)𝑟𝑦𝑠𝑖𝑛𝜃𝑠𝑖𝑛𝜙+𝐷𝑝𝑥)
𝑦
𝑞𝑦
ℎ
𝑖=1
𝑄−1
𝑄=0
𝑃−1
𝑃=0 (2)
∝ (∅ , ϕ) = 𝑃𝑥𝑄𝑦 ∑ ∑ ∑ 𝐴𝑝𝑥𝑒
−𝑗(𝑝(ℎ𝑥−ℎ𝑥𝑖)𝑟𝑥𝑠𝑖𝑛𝜃𝑠𝑖𝑛𝜙+𝐷𝑝𝑥)
𝑥
𝑝𝑥𝑒
−𝑗(𝑞(ℎ𝑦−ℎ𝑦𝑖)𝑟𝑦𝑠𝑖𝑛𝜃𝑠𝑖𝑛𝜙+𝐷𝑝𝑥)
𝑦
2𝑦
ℎ
𝑖=1
𝑄−1
𝑄=0
𝑃−1
𝑃=0 (3)
The direction of the APAA far field radiation pattern is (𝜃, 𝜑), which relates to amplitude variation, phase
shift variation, and radiation pattern. In a typical measurement setup, Figure 1 shows an APAA calibration
system with each antenna element connected to a digital phase shifter controller. Because of the phase
shifter’s amplitude and phase inaccuracies, higher order Fourier series are usually used to quantify array
power responses. Consequently, this research focus on an adequate and efficient algorithm applying
reconstruction of 2D signals analysis shown in the (1) to (3) on the missing samples. The 2D FFT of an
active phased array antenna is expressed in the (3). Where, ℎ = wave number.
ℎ =
2𝜋
𝜆
(4)
3. ISSN: 1693-6930
TELKOMNIKA Telecommun Comput El Control, Vol. 20, No. 4, August 2022: 892-900
894
Figure 1. An active phased array antenna measurement calibration schematic
The mutual effect, complex excitation of the amplitude, and phase shift variation of the antenna elements
with respect to the 𝑥 and 𝑦 axes are evaluated when determining the far field radiation pattern direction of the
𝑃 × 𝑄 APAA. The 𝑃𝑥 and 𝑄𝑦 are sample along the 𝑥 and 𝑦 directions respectively for the 2×2 APAA as
shown in the (7). The signal analysis is examined on a full set of 𝐺 where:
𝑛𝑖 = ℎ𝑥 − ℎ𝑥𝑖 ; 𝑚𝑖 = ℎ𝑦 − ℎ𝑦𝑖 (5)
The ℎ𝑥𝑖 and ℎ𝑦𝑖 represents frequency of the ith component in the 2×2 APAA.
𝐺 = {𝑔(𝑥, 𝑦) ∶ 𝑥𝜖{1, … , 𝑃𝑥}, 𝑦{1, … , 𝑄𝑦}} (6)
𝐺 = ∑ 𝐴𝑄𝑥𝐴𝑃𝑦𝑒
−𝑗{𝑝𝑛𝑖𝑠𝑖𝑛𝜃𝑐𝑜𝑠𝜙
𝑥
𝑄𝑥
+𝑞𝑚𝑖𝑠𝑖𝑛𝜃𝑠𝑖𝑛𝜙
𝑦
𝑄𝑦
}
ℎ
𝑖 (7)
Consequently, the error emmanting from the amplitude, phase shift and mutual coupling variations
affects the radiation pattern of the 2×2 APAA. These errors are considered as the missing samples in the 2D
spectral domain analysis. The zero-value expressed in the (8) act as an addition of noise to the signal, and the
error is given as:
𝜀(𝑥, 𝑦) = {0,𝑓𝑜𝑟 (𝑥,𝑦) 𝑎𝑣𝑎𝑖𝑙𝑎𝑏𝑙𝑒
−𝑔 (𝑥,𝑦),𝑓𝑜𝑟(𝑥,𝑦)missing
(8)
The noise is assumed to be zero-valued at the position of available signal samples, whereas the noise
neutralizes the signal samples setting to zero at the position of missing samples. The available signal samples
are expressed in the 2D FFT as:
𝑆(ℎ𝑥, ℎ𝑦) = ∑ ∑ {𝐺(𝑥, 𝑦) + 𝜀(𝑥, 𝑦)}
𝑃𝑦
𝑦=1
𝑄𝑥
𝑥=1 (9)
To analyze the error variations in the signal, the following cases are considered in the (10) to (13).
− If ℎ𝑥 = ℎ𝑥𝑖, ℎ𝑦 = ℎ𝑦𝑖; the assumption is expressed as:
𝐸{𝑆(ℎ𝑥, ℎ𝑦} = 𝐴𝑝𝑥𝐴𝑞𝑦𝐸 {∑ ∑ 𝑒
−𝑗[𝑝((ℎ𝑥−ℎ𝑥𝑖)𝑠𝑖𝑛𝜃𝑐𝑜𝑠𝜙+𝐷𝑝𝑥)
𝑥
𝑃𝑥
+𝑥((ℎ𝑦−ℎ𝑦𝑖)𝑠𝑖𝑛𝜃𝑠𝑖𝑛𝜙+𝐷𝑞𝑦)
𝑦
𝑄𝑦
]
𝑄𝑦
𝑦=1
𝑃𝑥
𝑥=1 } + ⋯ + ⋯ +
𝑉𝑘𝐸 {∑ ∑ 𝑒
−𝑗[𝑝((ℎ𝑥−ℎ𝑥𝑖)𝑠𝑖𝑛𝜃𝑐𝑜𝑠𝜙+𝐷𝑝𝑥)
𝑥
𝑄𝑥ℎ
+𝑛((ℎ𝑦−ℎ𝑦𝑘)𝑠𝑖𝑛𝜃𝑠𝑖𝑛+𝐷𝑞𝑦)
𝑦
𝑄𝑦𝑘
]
𝑄𝑥𝑘
𝑦=1
𝑃𝑥𝑘
𝑥=1 }
𝑉𝑘 = 𝐴𝑝𝑥𝑘𝐴𝑞𝑦𝑘, 𝐸{𝑆(ℎ𝑥, ℎ𝑦)} = 𝐸{𝑆(ℎ𝑥ℎ, ℎ𝑦ℎ)} = 𝑉ℎ𝑘𝑃𝑥𝑘𝑄𝑦𝑘 (10)
4. TELKOMNIKA Telecommun Comput El Control
A compressed sensing approach for antenna array calibration (Akinwale Oluwaseyi Fadamiro)
895
− If ℎ𝑥 ≠ ℎ𝑥𝑖, ℎ𝑦 ≠ ℎ𝑦𝑖; the assumption is expressed as:
𝐸{𝑆(ℎ𝑥, ℎ𝑦)} = 0,
𝑉𝑘𝑃𝑥𝑄𝑦 = 𝑉𝑘𝐸 {∑ ∑ 𝑒
−𝑗[𝑝((ℎ𝑥−ℎ𝑥𝑘)𝑠𝑖𝑛𝜃𝑐𝑜𝑠+𝐷𝑝𝑥)
𝑥
𝑃𝑥𝑘
+𝑞((ℎ𝑦−ℎ𝑦𝑘)𝑠𝑖𝑛𝜃𝑐𝑜𝑠∅+𝐷𝑞𝑦)
𝑦
𝑄𝑦𝑘
]
𝑄𝑦𝑘
𝑦=1
𝑝𝑥𝑘
𝑥=1 } (11)
The noise affecting the P × Q APAA is expressed in 𝑠(ℎ𝑥, ℎ𝑦) as:
𝜎𝑖
2
{𝑆(ℎ𝑥 ≠ ℎ𝑥𝑖, ℎ𝑦 ≠ ℎ𝑦𝑖)} = 𝑃𝑥𝑘𝑄𝑦𝑘𝐸{𝐺(𝑥, 𝑦)𝑄∗(𝑥, 𝑦)}
+ 𝑃𝑥𝑘𝑄𝑦𝑘(𝑃𝑥𝑘𝑄𝑦𝑘 − 1) . 𝐸{𝐺(𝑥, 𝑦)𝐺∗(𝑝, 𝑞)} = 𝑉𝑖𝑘
2
𝑃𝑥𝑘𝑄𝑦𝑘 + 𝑍𝑖𝑘
2
𝑃𝑥𝑘𝑄𝑦𝑘(𝑃𝑥𝑘𝑄𝑥𝑘 − 1)
−1
𝑃𝑥𝑘𝑄𝑦𝑘−1
(12)
Signal components (useful signals) and noise components can be distinguished using estimated
noise parameters such as amplitude, phase shift, and mutual coupling fluctuations. As a result, the level of
noise can be estimated, and the position of actual signal components above the noise can be detected, and the
impacted elements can then be calibrated to the original signal. The entire variance of noise in the 2D FFT
due to amplitude, phase shifter errors, or external errors (noise) on the elements can be stated in the (13) as:
𝜎2
= ∑ 𝑍𝑖𝑘
2
ℎ
𝑖=1 𝑃𝑥𝑘𝑄𝑦𝑘
𝑃𝑥𝑄𝑦− 𝑃𝑥𝑘𝑄𝑦𝑘
𝑃𝑥𝑄𝑦−1
(13)
3. RESEARCH METHODOLOGY
In the previous section, we demonstrared how to analyze the noise variance in the 2D APAA caused
by the amplitude, phase shift, mutual coupling variations and external noise disturbances. To attain a reliable
array diagnosis technique that detects the defective elements position with minimal diagnosis time while
calibrating the faulty elements to the original signal known as the reference state or state 0 at the receiver,
as shown in Figure 2, it is necessary to investigate the effect of noise disturbance in the APAA. Calibration
technique estimate and compensate antenna array errors, as well as associated errors and their location.
Figure 2. Compressive sensing and vector weight technique for an active phased array antenna calibration
3.1. Fault detection and calibration at the receiver
3.1.1. Description of the method
The vector of measurements 𝑦 containing incorrect 𝑃𝑥𝑘𝑄𝑦𝑘 elments out of the original 𝑃𝑥𝑄𝑦 signal is
expressed as:
𝑓 = 𝑠(𝛺) (14)
The analysis of the Fourier transform of the signal is represented in the 2D FFT matrix form as
𝐷 (𝑃𝑥𝑘𝑄𝑦𝑘 ⊗ 𝑃𝑥𝑄𝑦), this is extracted from the KRONECK PRODUCT of two FFT matrices as expressed in
the (15).
𝐷 = 𝐹𝐹𝑇 𝑃𝑥𝑘𝑄𝑦𝑘 ⊗ 𝐹𝐹𝑇 𝑃𝑥𝑄𝑦 (15)
The unobstructed APAA output signal 𝑓(𝑡) is derived by multiplying the complex weight vector (𝑢) and
signal vector 𝐷(𝑡) as shown in Figure 2 to give.
5. ISSN: 1693-6930
TELKOMNIKA Telecommun Comput El Control, Vol. 20, No. 4, August 2022: 892-900
896
𝐹(𝑡) = 𝑈𝑇
. 𝐷(𝑡) (16)
𝑓
̃(𝑡) = 𝑈𝑇
. 𝐷(𝑡) = 𝑈1 … 𝑈𝑁 . [
𝐷1(𝑡)
⋮
𝐷𝑁(𝑡)
] (17)
The complex factors 𝑧𝑛 in each branch models the amplitude, phase shift, and mutual coupling effects or
external sounds deviation of the signal. The deviations in complex notation are described by the diagonal
entries 𝑧𝑛𝑛, 𝑛 𝜖{1, … 𝑁}. Hence, the disturbed output signal is expressed as:
𝑓
̃(𝑡) = 𝑈𝑇
[
𝑍1𝐷1(𝑡)
⋮
𝑍𝑁𝐷𝑁(𝑡)
] = 𝑈𝑇
𝑍𝐷(𝑡) (18)
The disturbed weight vector 𝑈
̃𝑇
is given as:
𝑓
̃(𝑡) = 𝑈𝑇
Ζ𝐷(𝑡) = (𝑈1𝑍1 … 𝑈𝑁𝑍𝑁) + 𝐷(𝑡) = 𝑈
̃𝑇
. 𝐷(𝑡) (19)
The angular frequency (𝜔) and transmission angle (𝜃) controls the 𝑃 × 𝑄 APAA calibration by the steering
vector of the array biased on the weight vector as shown in the (20).
𝑈𝑐𝑎𝑙
𝑇
= 𝑈𝑐𝑎𝑙
𝑇
(𝜔, 𝜃) = [1, 𝑒𝑗𝜔𝑧,𝑐𝑜𝑠
𝜃
𝑐 , … , 𝑒𝑗𝜔𝑧𝑁−1𝑐𝑜𝑠
𝜃
𝑐] (20)
Where, 𝑐 = speed of propagation.
Applying the calibrated weight vector compensates the deviation in the array branches in the beamforming as:
𝑓(𝑡) = 𝑈
̃𝑐𝑎𝑙
𝑇 (𝜔, 𝜃) 𝑍𝐷(𝑡) (21)
3.2. APAA error detection and calibration technique
Figure 3(a) shows the components of the APAA which includes, the antenna array, power divider
and the 6 bits phase shifter. The experimental procedure of this research study on the the 2×2 APAA is
carried out in Figure 3(b) with the antenna elements radiating in free space and the amplitude and phase shifts
of this AUT is measured at far field without failure and expressed as the reference state or state 0. The 2×2
antenna reflection coefficetion is investigated and measured using a vector network analyzer (VNA),
showing the operating frequency at 3.5 GHz as displayed in Figure 3(c). Hence, modifying the array factor
(𝛼) in +𝑧 hemisphere is given as:
𝐴 = 𝑠𝑖𝑛 𝜃 𝑐𝑜𝑠 𝜑
𝐵 = 𝑠𝑖𝑛 𝜃 𝑠𝑖𝑛 𝜑
∝ ( 𝐴, 𝐵) = 𝐷 (𝑈𝑝𝑥
𝑇
. 𝑈𝑞𝑦) (22)
Consdering the complex weight 𝑈 distributed along the 𝑥 and 𝑦 directions of the 𝑃 × 𝑄 APAA, the power
pattern is expressed as:
𝑃 =∝ (𝐴, 𝐵) 𝑥 ∝ (𝐴, 𝐵)∗
(23)
(𝑥) = element by element multiplication
(∗) = complex conjugate operation
Therefore, applying the distributive property on the (23), it can be expressed:
𝑃 = (𝐷(𝑈𝑝𝑥
𝑇
) 𝑥 (𝐷(𝑈𝑝𝑥
𝑇
))∗
) . (𝐷(𝑈𝑄𝑦) 𝑥 (𝐷(𝑈𝑄𝑦))∗
) (24)
On the (24) illustrates that a power pattern is produced by substituting multiplication with an auto-convolution
(⨂) of the complex weighting elements.
The rectangular 𝑃 × 𝑄 APAA power pattern employes two orthogonal 2D arrays written as:
𝑃 = ((𝐷(𝑈𝑝𝑥
𝑇
⊗ 𝑈𝑝𝑥
𝑇
)) ∗
) . ((𝐷(𝑈𝑄𝑦 ⊗ 𝑈𝑄𝑦))) (25)
6. TELKOMNIKA Telecommun Comput El Control
A compressed sensing approach for antenna array calibration (Akinwale Oluwaseyi Fadamiro)
897
The combining of the two 1-D element patterns necessitates the use of a separate post processing
unit at the receiver in order to obtain the necessary spatial power pattern function. The synthesizing pattern
evaluates the complex weights (𝑈𝑚𝑥, 𝑈𝑛𝑦) and distance between elements (𝑝𝑑𝑥, 𝑞𝑑𝑦) along 𝑥 and 𝑦 axes.
In the compressive sensing technique for the APAA calibration system, minimization of vector 𝑈 is a typical
basic pursuit obstacle. The expression below in the (26) and (27) represents the 2-D power pattern along the 𝜃
and 𝜑 plane.
[𝑃(𝜃)]1∝𝑝𝑥
𝑇
= [𝑈𝑥]1∝𝑝𝑥
𝑇
∝ [𝐿𝑥]𝑝𝑥
𝑇
(26)
[𝑃(∅)]1∝𝑄𝑦
𝑇
= [𝑈𝑦]1∝𝑄𝑦
𝑇
∝ [𝐿𝑥]𝑄𝑦
𝑇
(27)
Where:
𝑃(𝜃) = power pattern splits along θ Plane
𝑃(𝜙) = power pattern splits along φ Plane
𝑈𝑥 = 𝑥 plane complex excitation vector in the 𝑃 × 𝑄 APAA
𝑈𝑦 = 𝑦 plane complex excitation vector in the 𝑃 × 𝑄 APAA
𝐿 = matrix encoding the steering vectors
4. RESULTS AND DISCUSSION
This section presents a practical example for calibrating a 2×2 APAA as shown in Figure 3(a).
Before imposing amplitude, phase shift, and mutual coupling changes or external noises deviations on the
array, the four planar elements were simulated uniformly to determine their reference state 0. The amount of
computation for the proposed method is examined and the factors influencing the calibration accuracy are
analyzed qualitatively.
4.1. 2×2 APAA design and fabrication
A 2×2 APAA has been designed and fabricated using a 0.018 mm thick Rogers RO4350 Substrates.
To achieve a sufficient coupling condition for the rectangular geometry of the array, as illustrated in Figure 3(b),
the feeding ports are carefully determined along the four ports power divider used to achieve isolation between
the input ports while maintaining a matched condition of all ports. Figure 3(c) illustrates the operating
frequency of each of the four elements in the APAA with a maximum gain of 12.50 dB at reference state 0.
Therefore, each element in the array is coupled to a 6-bits phase shifter module for a microwave
network module to offer a configurable phase shift of the radio frequency (RF) signal. Figure 3(b) shows how
the 6-bit phase shifter employed in this work is used in phased arrays systems for high-frequency RF
applications. These phase shifters are coupled to a phase shifter controller, which has a four-way phase shift
output and is regulated by a four-way dual in-line package (DIP) switch to measure various states while in
the high and low states. Experimental studies using the Rohde and Schwarz network analyzer as shown in
Figure 3(c) illustrates the return loss measurements of the APAA at 3.5 GHz.
(a) (b) (c)
Figure 3. Photos of the experiment system: (a) 2×2 array, power divider and 6-bits phase shifter; (b) 2×2 planar
array experiment system in anechoic chamber; and (c) 2×2 array reflection coefficient measurement at 3.5 GHz
Many array far-fields are measured, illustrating the excitation error as the array is uniformly excited
considering the error variation. The 2 FFT is utilized to analyze the measured signals of the 2×2 APAA
system, as shown in section 2. As the antenna elements are energized, these data signals are saved. The signal
errors are detected using the scattering effect of the power divider in the array system, as well as faults caused
by amplitude and phase shifter errors were evaluated using the 𝑙1 compressive sensing method, as shown in
section 3. As a result, if the variation between the most recent calculated excitation error and the best among
7. ISSN: 1693-6930
TELKOMNIKA Telecommun Comput El Control, Vol. 20, No. 4, August 2022: 892-900
898
the previously calculated excitation errors is less than a target level, such as 10%, the average convergence
error is considered the array excitation error under uniform array excitation, and the calibration procedure
ends. The comparison of the genuine excitations and the calculated 𝑙1 compressive sensing yields the
calibration errors of this experimental calibration technique. Although, the calibration time increases due to
the complexity of system but the accuracy and effectiveness of the method compensates for time estimate of
the element under calibration (EUC) [25]. Figure 4(a) compares the pre-calibration, post-calibration, and
normalized radiation patterns with no excitation errors. In the range of the sidelobes and nulls of the radiation
patterns, the post-calibration pattern is substantially closer to the ideal pattern than the pre-calibration pattern.
Because the sidelobes and nulls are particularly sensitive to the array excitation, the agreement between the
post-calibration and the ideal radiation pattern suggests that the post-calibration excitations are very close to
the ideal excitations. Figure 4(b) and Figure 4(c) compares the pre-calibration, post-calibration, and
normalized radiation patterns with no excitation errors of the amplitude and phase excitation respectively.
The undesirable array excitation with inaccuracies must be calibrated since the actual array excitation affects
calibration accuracy. In practice, we can diagnose and calibrate antenna arrays under various array
excitations and select the most appropriate technique. Finally, the proposed calibration technique is validated
experimentally.
(a)
(b)
(c)
Figure 4. The idea, pre-calibration and post-calibration comparative analysis the 2×2 APAA measurement:
(a) radiation pattern, (b) amplitude, and (c) phase
8. TELKOMNIKA Telecommun Comput El Control
A compressed sensing approach for antenna array calibration (Akinwale Oluwaseyi Fadamiro)
899
5. CONCLUSION
This paper proposes a technique that can calibrate a 2×2 APAA simultaneously. The signal
measurements of the four elements in the APAA are analyzed with the reference state 0 where no errors exist
in the system. The key factor of this research study is to identify the problem from amplitude, phase shift, and
mutual coupling fluctuations or external noise deviation errors on the APAA and use comprehensive sensing
to model to resolve it. The toggling of the 6-bit phase shifters attached to each antenna element during the
measurement operation determines the accuracy, complexity, and hardware requirements of this approach.
To accomplish acceptable calibration, the phase settings are calibrated using 2D FFT signal data processing
and basic pursuit compressive sensing combined with the vector weight (𝑢). The efficiency of the suggested
APAA calibration technique is demonstrated in an experimental evaluation of a far field 2×2 active phased
array microstrip antenna array. It’s worth noting that these findings apply to radar communications, satellite
communications, massive MIMO, and military applications.
REFERENCES
[1] M. A. B. Abbasi, V. Fusco and D. E. Zelenchuk, "Compressive Sensing Multiplicative Antenna Array," in IEEE Transactions on
Antennas and Propagation, vol. 66, no. 11, pp. 5918-5925, Nov. 2018, doi: 10.1109/TAP.2018.2864651.
[2] J. J. Lee, E. M. Ferren, D. P. Woollen, and K. M. Lee, “Near-field probe used as a diagnostic tool to locate defective elements in
an array antenna,” IEEE Transactions on Antennas and Propagation, vol. 36, no. 6, pp. 884–889, Jun. 1988, doi: 10.1109/8.1192.
[3] O. M. Bucci, M. D. Migliore, G. Panariello, and P. Sgambato, "Accurate diagnosis of conformal arrays from near-field data using
the matrix method," IEEE Transactions on Antennas and Propagation, vol. 53, no. 3, pp. 1114–1120, Mar. 2005,
doi: 10.1109/TAP.2004.842656.
[4] A. Patnaik, B. Chowdhury, P. Pradhan, R. K. Mishra, and C. Christodolou, "An ANN application for fault finding in antenna
arrays," IEEE Transactions on Antennas and Propagation, vol. 55, no. 3, pp. 775–777, Mar. 2007,
doi: 10.1109/TAP.2007.891557.
[5] R. Iglesias, F. Ares, M. F. -Delgado, J. A. Rodriguez, J. Bregains, and S. Barro, "Element failure detection in linear antenna arrays
using case-based reasoning," IEEE Antennas and Propagation Magazine, vol. 50, no. 4, pp. 198–204, Aug. 2008,
doi: 10.1109/MAP.2008.4653709.
[6] B. -K. Yeo and Y. Lu, "Array failure correction with a genetic algorithm," IEEE Transactions on Antennas and Propagation,
vol. 47, no. 5, pp. 823–828, May 1999, doi: 10.1109/8.774136.
[7] J. A. Rodriguez, F. Ares, H. Palacios, and J. Vassal’lo, "Finding defective elements in planar arrays using genetic algorithms,"
Progress In Electromagnetics Research, vol. 29, pp. 25-37, 2000, doi: 10.2528/PIER00011401.
[8] Y. Alvarez, F. L. -Heras, B. A. D. -Casas, and C. Garcia, "Antenna diagnostics using arbitrary-geometry field acquisition
domains," IEEE Antennas and Wireless Propagation Letters, vol. 8, pp. 375–378, 2009, doi: 10.1109/LAWP.2009.2019108.
[9] A. Buonanno and M. D’Urso, "A novel strategy for the diagnosis of arbitrary geometries large arrays," IEEE Transactions on
Antennas and Propagation, vol. 60, no. 2, pp. 880–885, Feb. 2012, doi: 10.1109/TAP.2011.2173109.
[10] R. Palmeri, T. Isernia, and A. F. Morabito, "Diagnosis of Planar Arrays through Phaseless Measurements and Sparsity
Promotion," IEEE Antennas and Wireless Propagation Letters, vol. 18, no. 6, pp. 1273-1277, Jun. 2019,
doi: 10.1109/LAWP.2019.2914529.
[11] W. Li, W. Deng, and M. D. Migliore, "A deterministic far-field sampling strategy for array diagnosis using sparse recovery,"
IEEE Antennas and Wireless Propagation Letters, vol. 17, no. 7, pp. 1261–1265, Jul. 2018, doi: 10.1109/LAWP.2018.2841650.
[12] M. Salucci, A. Gelmini, G. Oliveri, and A. Massa, "Planar arrays diagnosis by means of an advanced Bayesian compressive
processing," IEEE Transactions on Antennas and Propagation, vol. 66, no. 11, pp. 5892–5906, Nov. 2018,
doi: 10.1109/TAP.2018.2866534.
[13] A. F. Morabito, R. Palmeri, and T. Isernia, "A compressive-sensing inspired procedure for array antenna diagnostics by a small
number of phaseless measurements," IEEE Transactions on Antennas and Propagation, vol. 64, no. 7, pp. 3260–3265, Jul. 2016,
doi: 10.1109/TAP.2016.2562669.
[14] M. D. Migliore, "Array diagnosis from far-field data using the theory of random partial Fourier matrices," IEEE Antennas and
Wireless Propagation Letters, vol. 12, pp. 745–748, 2013, doi: 10.1109/LAWP.2013.2270931.
[15] B. Fuchs, L. L. Coq, and M. D. Migliore, "Fast antenna array diagnosis from a small number of far-field measurements," IEEE
Transactions on Antennas and Propagation, vol. 64, no. 6, pp. 2227–2235, 2016, doi: 10.1109/TAP.2016.2547023.
[16] M. A. S. -Natera, R. M. R. -Osorio, L. D. H. Ariet, and M. S. -Pérez, "Novel Reception and Transmission Calibration Technique
for Active Antenna Array Based on Phase Center Estimation," IEEE Transactions on Antennas and Propagation, vol. 65, no. 10,
pp.5511–5522, 2017, doi: 10.1109/TAP.2017.2738067.
[17] R. Long, J. Ouyang, F. Yang, W. Han, and L. Zhou, "Multi-element phased array calibration method by solving linear equations,"
IEEE Transactions on Antennas and Propagation, vol. 65, no. 6, pp. 2931–2939, 2017, doi: 10.1109/TAP.2017.2694767.
[18] C. -N. Hu, "A novel method for calibrating deployed active antenna arrays," IEEE Transactions on Antennas and Propagation,
vol. 63, no. 4, pp. 1650–1657, 2015, doi: 10.1109/TAP.2015.2398119.
[19] R. Sorace, "Phased array calibration," IEEE Transactions on Antennas and Propagation, vol. 49, no. 4, pp. 517–525, Apr. 2001,
doi: 10.1109/8.923310.
[20] R. Long and J. Ouyang, "Planar Phased Array Calibration Based on Near-Field Measurement System," Progress in
Electromagnetics Research C, vol. 71, pp. 25–31, 2017, doi: 10.2528/PIERC16112004.
[21] Y. Gong, R. Wang, and P. Wang, "Improved Phase Encoding Calibration for Active Phased Array Antennas of SAR," IEEE
Geoscience and Remote Sensing Letters, vol. 13, no. 6, pp. 767–771, 2016, doi: 10.1109/LGRS.2016.2542104.
[22] C. He, X. Liang, J. Geng, and R. Jin, "Parallel calibration method for phased array with harmonic characteristic analysis," IEEE
Transactions on Antennas and Propagation, vol. 62, no. 10, pp. 5029–5036, Oct. 2014, doi: 10.1109/TAP.2014.2341700.
[23] T. Takahashi, Y. Konishi, and I. Chiba, "A Novel Amplitude Only Measurement Method to Determine Element Fields in Phased
Arrays," IEEE Transactions on Antennas and Propagation, vol. 60, no. 7, pp. 3222–3230, 2012, doi: 10.1109/TAP.2012.2196961.
[24] S. Costanzo, A. Borgia, G. Di Massa, D. Pinchera, and M. D. Migliore, "Radar array diagnosis from undersampled data using a
compressed sensing/sparse recovery technique," Journal of Electrical and Computer Engineering, vol. 2013, 2013,
doi: 10.1155/2013/627410.
9. ISSN: 1693-6930
TELKOMNIKA Telecommun Comput El Control, Vol. 20, No. 4, August 2022: 892-900
900
[25] A. O. Fadamiro, A. A. Semomhe, O. J. Famoriji, and F. Lin, "A Multiple Element Calibration Algorithm for Active Phased Array
Antenna," in IEEE Journal on Multiscale and Multiphysics Computational Techniques, vol. 4, pp. 163-170, 2019,
doi: 10.1109/JMMCT.2019.2923113.
BIOGRAPHIES OF AUTHORS
Akinwale Oluwaseyi Fadamiro received the B. Eng. and M. Eng. in Electrical
and Electronics Engineering, in 2008 and 2014 respectively at the Federal University of
Technology Akure (FUTA), Akure, Nigeria. In 2016, he was awarded a Ph.D CAS-TWAS
president fellowship at the University of Science and Technology of China (USTC), China. He
obtained his Ph.D. degree in Electronic Science and Technology, University of Science and
Technology of China (USTC), Hefei, Anhui Province, China, in 2020. He is currently a
Lecturer with the Department of Computer Engineering, Federal University of Technology
Akure (FUTA), Akure, Nigeria. His research interests includes: active phased array antenna
design, antenna design, optimization, machine learning, and calibration. He can be contacted at
email: aofadamiro@futa.edu.ng and aofadamiro@mail.ustc.edu.cn.
Fujiang Lin M’93–SM’99) received the B.S. and M.S. degrees in electrical
engineering from the University of Science and Technology of China (USTC), Hefei, China, in
1982 and 1984, respectively, and the Dr.-Ing. degree in electrical engineering from the
University of Kassel, Kassel, Germany, in 1993. He joined the National University of
Singapore, Singapore, as a Research Scientist in 1993. In 1995, he joined the Institute of
Microelectronics (IME), Singapore, as a Technical Staff Member, where he pioneered
practical RF modeling for MMIC/RFIC development. In 1999, he joined HP EEs of Singapore
as the Technical Director. He has established the Singapore Microelectronics Modeling
Center, providing accurate state-of-the-art device and package characterization and modeling
solution service worldwide. From 2001 to 2002, he started up the Transilica Singapore Pte.
Ltd., Singapore, a Research and Development Design Center of Transilica Inc., a Bluetooth
and the IEEE 802.11 a/b wireless system-on-chip (SoC) company. In 2002, he joined the
Chartered Semiconductor Manufacturing Ltd., Singapore (now Global Foundries, second-
largest foundry). In 2010, he joined the USTC as a Full Professor under the Chinese “1000
Talents Program”. He is the Executive Director of the MESIC, Hefei, China, “Micro-/Nano-
Electronic System Integration Research and Development Center,” which is jointly established
by USTC and IMECAS. He is the head of department of the Electronics of Science and
Technology, and Founding vice Dean of the School of Microelectronics. He can be contacted
at email: linfj@ustc.edu.cn.