Electronics

15 pages, 1291 KiB

Open AccessFeature PaperArticle

A PLL-Based Online Estimation of Induction Motor Consumption Without Electrical Measurement

by Thierry Doget, Erik Etien, Laurent Rambault and Sébastien Cauet

Electronics 2019, 8(4), 469; https://doi.org/10.3390/electronics8040469 - 25 Apr 2019

Cited by 5 | Viewed by 3139

This work is supported by a company wishing to develop new products in the field of energy monitoring in industry. It concerns the real-time estimation of the electrical consumption of an asynchronous motor without electrical measurement. The challenge consists of estimating the characteristic [...] Read more.

This work is supported by a company wishing to develop new products in the field of energy monitoring in industry. It concerns the real-time estimation of the electrical consumption of an asynchronous motor without electrical measurement. The challenge consists of estimating the characteristic quantities of the motor (speed, torque, powers, efficiency) with only one vibratory measurement, information on the nameplate and commercial documentation available online. To obtain a real-time estimate, traditional FFT analysis is replaced by a PLL initially designed for power grid analysis. So, the second challenge is to modify this PLL for use with vibratory measurement characterized by a low signal-to-noise ratio, amplitude variations and a non-stationary behavior. A complete design and experimental tests are presented to validate the proposed approach. Full article

(This article belongs to the Section Computer Science & Engineering)

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22 pages, 4718 KiB

Open AccessArticle

Intelligent Micro Energy Grid in 5G Era: Platforms, Business Cases, Testbeds, and Next Generation Applications

by Young-Myoung Kim, Daekyo Jung, Youngeun Chang and Dae-Hyun Choi

Electronics 2019, 8(4), 468; https://doi.org/10.3390/electronics8040468 - 25 Apr 2019

Cited by 26 | Viewed by 8360

Abstract

As fifth-generation mobile communication systems give rise to new smart grid technologies, such as distributed energy resources, advanced communication systems, the Internet of Things, and big data analytics, the development of novel platforms and business models that ensure reliability and profitability of microgrid [...] Read more.

As fifth-generation mobile communication systems give rise to new smart grid technologies, such as distributed energy resources, advanced communication systems, the Internet of Things, and big data analytics, the development of novel platforms and business models that ensure reliability and profitability of microgrid operations become increasingly important. In this study, we introduce an open micro energy grid platform to operate the widely distributed microgrids in Korea. Subsequently, we present commercial microgrid business models supported by the open micro energy grid platform equipped with an artificial intelligence engine and provide test results from testbeds connected to the platform. In contrast to the existing microgrid business models in the market, we propose a universal architecture and business model of the future microgrid, comprising (i) an energy robot-management operation business model, (ii) electric vehicle-based demand response, (iii) blockchain technology for energy trading, and (iv) a service-oriented business model. Finally, we propose a new business model for an intelligent virtual power plant (VPP) operator along with the architecture of the VPP and its proof of concept (PoC). We expect the proposed business model to provide energy solution providers with guidelines to develop various VPP services. Full article

(This article belongs to the Special Issue IoT in 5G)

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27 pages, 4035 KiB

Open AccessArticle

A Novel EMR Integrity Management Based on a Medical Blockchain Platform in Hospital

by Lei Hang, Eunchang Choi and Do-Hyeun Kim

Electronics 2019, 8(4), 467; https://doi.org/10.3390/electronics8040467 - 25 Apr 2019

Cited by 83 | Viewed by 11841

Abstract

Recent advancements in information and communication technology is enabling a significant revolution in e-Health research and industry. In the case of personal medical data sharing, data security and convenience are crucial requirements to the interaction and collaboration of electronic medical record (EMR) systems. [...] Read more.

Recent advancements in information and communication technology is enabling a significant revolution in e-Health research and industry. In the case of personal medical data sharing, data security and convenience are crucial requirements to the interaction and collaboration of electronic medical record (EMR) systems. However, it’s hard for current systems to meet these requirements as they have inconsistent structures in terms of security policies and access control models. A new solution direction is essential to enhance data-accessing while regulating it with government mandates in privacy and security to ensure the accountability of the medical usage data. Blockchain seems to pave the way for revolution in the conventional healthcare industry benefiting by its unique features such as data privacy and transparency. In this paper, a blockchain-based medical platform using a smart contract is proposed to secure the EMR management. This approach provides patients a comprehensive, immutable log and easy access to their medical information across different departments within the hospital. A case study for hospital is built on a permissioned network, and a series of experimental tests are performed to demonstrate the usability and efficiency of the designed platform. Lastly, a benchmark study by leveraging various performance metrics is made and the outcomes indicate that the designed platform surpasses the ability of existing works in various aspects. The results of this work reveal that the proposed solution has the great potential to accelerate the development of a decentralized digital healthcare ecosystem. Full article

(This article belongs to the Section Computer Science & Engineering)

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18 pages, 9567 KiB

Open AccessArticle

Analysis and Design of a ZVT Resonant Boost Converter Using an Auxiliary Resonant Circuit

by Hee-Jun Lee and Young-Ho Kim

Electronics 2019, 8(4), 466; https://doi.org/10.3390/electronics8040466 - 25 Apr 2019

Cited by 4 | Viewed by 4672

Abstract

In this paper, a new zero voltage transition (ZVT) resonant boost converter is proposed. A typical boost converter generates switching losses at turning on and turning off, and these losses cause a reduction in the efficiency of the whole system. This proposed ZVT [...] Read more.

In this paper, a new zero voltage transition (ZVT) resonant boost converter is proposed. A typical boost converter generates switching losses at turning on and turning off, and these losses cause a reduction in the efficiency of the whole system. This proposed ZVT resonant boost converter utilizes a soft switching method, using an auxiliary circuit with a resonant inductor, capacitor, and two auxiliary switches. Therefore, it can reduce switching losses more so than the conventional hard switching converter. Also, the conduction period of the resonant inductor current is reduced by using a modified circuit. An experiment is conducted with the converter, which steps up the voltage from 200 V to 380 V and its switching frequency and output power are 30 kHz and 4 kW, respectively. It is confirmed that the experimental results and simulation results are the same and the validity of this proposed converter is verified. The conventional converter and proposed converter are analyzed by comparing the experimental results of two converters under the same conditions. It is confirmed that all switches can achieve soft switching and the proposed converter improves on the conventional converter by measuring the efficiency of two converters. Full article

(This article belongs to the Special Issue Advanced Power Conversion Technologies)

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7 pages, 229 KiB

Open AccessEditorial

Applications of Power Electronics

by Frede Blaabjerg, Tomislav Dragicevic and Pooya Davari

Electronics 2019, 8(4), 465; https://doi.org/10.3390/electronics8040465 - 25 Apr 2019

Cited by 9 | Viewed by 9298

Abstract

Power electronics technology is still an emerging technology, and it has found its way into many applications, from renewable energy generation (i [...] Full article

(This article belongs to the Special Issue Applications of Power Electronics)

11 pages, 3970 KiB

Open AccessArticle

A 3GS/s 12-bit Current-Steering Digital-to-Analog Converter (DAC) in 55 nm CMOS Technology

by Dong Wang, Xuan Guo, Lei Zhou, Danyu Wu, Jian Luan, Huasen Liu, Jin Wu and Xinyu Liu

Electronics 2019, 8(4), 464; https://doi.org/10.3390/electronics8040464 - 25 Apr 2019

Cited by 4 | Viewed by 4979

Abstract

A 3GS/s 12-bit current-steering digital-to-analog converter (DAC) fabricated in 55 nm complementary metal–oxide–semiconductor (CMOS) technology has been presented. A partial randomization dynamic element matching (PRDEM) method based on switching sequence optimization is proposed to mitigate the mismatch effect and suppress the harmonic distortion [...] Read more.

A 3GS/s 12-bit current-steering digital-to-analog converter (DAC) fabricated in 55 nm complementary metal–oxide–semiconductor (CMOS) technology has been presented. A partial randomization dynamic element matching (PRDEM) method based on switching sequence optimization is proposed to mitigate the mismatch effect and suppress the harmonic distortion with low hardware complexity. In the switching current cell, the cascode structure together with “always-ON” small current sources are used to keep the output impedance high and uniform. A compact layout of the switching current array is carefully designed, featuring short wires routing and small parasitic capacitance. According to the measured results at 3GS/s, this DAC demonstrates a spurious-free dynamic range (SFDR) of 74.64 dBc at low frequency and 50 dBc at 1.5 GHz output. The chip occupies an active area of 0.2 × 0.48 mm² and consumes a total power of 495 mW. Full article

(This article belongs to the Section Semiconductor Devices)

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23 pages, 25940 KiB

Open AccessArticle

A Rapid Accurate Recognition System for Radar Emitter Signals

by Jingpeng Gao, Liangxi Shen, Lipeng Gao and Yi Lu

Electronics 2019, 8(4), 463; https://doi.org/10.3390/electronics8040463 - 25 Apr 2019

Cited by 12 | Viewed by 3527

Abstract

Radar signal recognition is an indispensable part of an electronic countermeasure system. In order to solve the problem that the current techniques have, which is a low recognition rate and a slow recognition speed for radar signals, a rapid accurate recognition system is [...] Read more.

Radar signal recognition is an indispensable part of an electronic countermeasure system. In order to solve the problem that the current techniques have, which is a low recognition rate and a slow recognition speed for radar signals, a rapid accurate recognition system is proposed, especially for when multiple signals arrive at the receiver. The proposed system can recognize eight types of radar signals while separating signals: binary phase shift keying (BPSK), linear frequency modulation (LFM), Costas, Frank code, and P1–P4 codes. Regression variational mode decomposition (RVMD) is explored to separate the received signals, which saves time for parameter optimization of variational mode decomposition (VMD). Furthermore, signal separation and a noise removal technique based on VMD and the first component recognition technique based on a deep belief network (DBN) are proposed. In addition, in order to overcome the loss of the secondary component caused by signal separation, a fusion network is explored to increase the recognition rate of the secondary component in a short time. The simulation results show that the recognition system achieves an overall recognition rate of 99.5% and 94% at a signal-to-noise ratio (SNR) of 0 dB when receiving single signals and double signals, while spending 0.8 s and 2.23 s, respectively. The proposed system can also be used to recognize medical and mechanical signals. Full article

(This article belongs to the Section Circuit and Signal Processing)

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10 pages, 1507 KiB

Open AccessArticle

On Secrecy Performance of the Strong User in MISO-NOMA Visible Light Communication System

by Xiang Zhao and Jinyong Sun

Electronics 2019, 8(4), 462; https://doi.org/10.3390/electronics8040462 - 25 Apr 2019

Cited by 3 | Viewed by 2555

Abstract

Since successive interference cancellation in non-orthogonal multiple access (NOMA) is enabled at the strong user to remove the signal of the weak user, if the information safety of the strong user cannot be ensured, neither can the weak user. The physical-layer security of [...] Read more.

Since successive interference cancellation in non-orthogonal multiple access (NOMA) is enabled at the strong user to remove the signal of the weak user, if the information safety of the strong user cannot be ensured, neither can the weak user. The physical-layer security of the strong user in a two-user multiple-input single-output (MISO)-NOMA visible light communication (VLC) system in the presence of a passive eavesdropper was studied, with multiple light-emitting diodes (LEDs) transmitting and a photodiode (PD) receiver receiving. To demonstrate the superiority of the MISO-NOMA VLC system over the SISO-NOMA VLC system, numerical simulations were made, and results show that the secrecy outage probability (SOP) performance of the strong user in the MISO-NOMA VLC system is superior to that in the SISO-NOMA VLC system. Furthermore, the SOP of the strong user depends highly on the room arrangement, the difference between the legitimate channel and eavesdropper channel, and the properties of the LEDs and PD. Full article

(This article belongs to the Special Issue Visible Light (VLC) and Camera Communication)

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12 pages, 3531 KiB

Open AccessArticle

Active-Model-Based Control for the Quadrotor Carrying a Changed Slung Load

by Kui Yi, Xiao Liang, Yuqing He, Liying Yang and Jianda Han

Electronics 2019, 8(4), 461; https://doi.org/10.3390/electronics8040461 - 25 Apr 2019

Cited by 22 | Viewed by 4815

Abstract

In this paper, a simple active-model-based control scheme is developed for the quadrotor slung load (QSL) system. The scheme works to improve the rejection of the influences caused by the abruptly changed load as a complementary enhancement while maintaining the structure and parameters [...] Read more.

In this paper, a simple active-model-based control scheme is developed for the quadrotor slung load (QSL) system. The scheme works to improve the rejection of the influences caused by the abruptly changed load as a complementary enhancement while maintaining the structure and parameters of the original controller. A linearized model is first constructed with respect to the hovering state of a quadrotor. Modeling error is then introduced to describe the uncertainties caused by the load change and the simplified model. The modeling error is actively estimated by a Kalman filter (KF), while the estimation is further integrated into a normal controller, to enhance its performance of disturbance rejection. Experiments are conducted on a quadrotor controlled by the Pixhawk, which is one of the most popular controllers commercially available on the market. The improvements of the proposed scheme are shown by the comparisons between the controls with and without the active-model-based enhancement. The experiments also indicate that, with its simple structure and less computational algorithm, this active-model-based enhancement would be a feasible approach to enhance the commercial UAV controller to handle more uncertainties. Full article

(This article belongs to the Special Issue Autonomous Navigation Systems for Unmanned Aerial Vehicles)

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17 pages, 8881 KiB

Open AccessArticle

An INS/Geomagnetic Integrated Navigation Algorithm Based on Matching Strategy and Hierarchical Filtering

by Xiusheng Duan, Jing Xiao, Xiaohui Qi and Yifei Liu

Electronics 2019, 8(4), 460; https://doi.org/10.3390/electronics8040460 - 25 Apr 2019

Cited by 11 | Viewed by 3373

Abstract

To improve the positioning accuracy of an inertial/geomagnetic integrated navigation algorithm, a combined navigation method based on matching strategy and hierarchical filtering is proposed. First, the PDA-ICCP geomagnetic matching algorithm is improved. On basis of evaluating the distribution of magnetic measurements, a number [...] Read more.

To improve the positioning accuracy of an inertial/geomagnetic integrated navigation algorithm, a combined navigation method based on matching strategy and hierarchical filtering is proposed. First, the PDA-ICCP geomagnetic matching algorithm is improved. On basis of evaluating the distribution of magnetic measurements, a number of controllable magnetic values are regenerated to participate in the geomagnetic matching algorithm (GMA). As a result, accuracy of the matching algorithm is ensured and its efficiency is improved. Secondly, the integrated navigation filter is designed based on the hierarchical filtering strategy, in which the navigation information of the geomagnetic matching module and inertial navigation module are respectively filtered and fused in the main filter. In this way, the shortcoming that GMA is unable to provide continuous and real-time navigation information is overcome. Meanwhile, precision of the inertial/geomagnetic integrated navigation algorithm is improved. Finally, the feasibility and validity of the proposed algorithm are verified by simulation and physical experiments. Compared with the integrated filtering algorithm which directly uses the error equation of inertial navigation system (INS) as the state equation, the proposed hierarchical filtering algorithm can achieve higher positioning precision. Full article

(This article belongs to the Section Microwave and Wireless Communications)

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21 pages, 975 KiB

Open AccessArticle

AN-Aided Secure Beamforming in Power-Splitting-Enabled SWIPT MIMO Heterogeneous Wireless Sensor Networks

by Weili Ge, Zhengyu Zhu, Wanming Hao, Yi Wang, Zhongyong Wang, Qiong Wu and Zheng Chu

Electronics 2019, 8(4), 459; https://doi.org/10.3390/electronics8040459 - 25 Apr 2019

Cited by 3 | Viewed by 2849

Abstract

In this paper, we investigate the physical layer security in a two-tier heterogeneous wireless sensor network (HWSN) depending on simultaneous wireless information and power transfer (SWIPT) approach for multiuser multiple-input multiple-output wiretap channels with artificial noise (AN) transmission, where a more general system [...] Read more.

In this paper, we investigate the physical layer security in a two-tier heterogeneous wireless sensor network (HWSN) depending on simultaneous wireless information and power transfer (SWIPT) approach for multiuser multiple-input multiple-output wiretap channels with artificial noise (AN) transmission, where a more general system framework of HWSN only includes a macrocell and a femtocell. For the sake of implementing security enhancement and green communications, the joint optimization problem of the secure beamforming vector at the macrocell and femtocell, the AN vector, and the power splitting ratio is modeled to maximize the minimal secrecy capacity of the wiretapped macrocell sensor nodes (M-SNs) while considering the fairness among multiple M-SNs. To reduce the performance loss of the rank relaxation from the SDR technique while solving the non-convex max–min program, we apply successive convex approximation (SCA) technique, first-order Taylor series expansion and sequential parametric convex approximation (SPCA) approach to transform the max–min program to a second order cone programming (SOCP) problem to iterate to a near-optimal solution. In addition, we propose a novel SCA-SPCA-based iterative algorithm while its convergence property is proved. The simulation shows that our SCA-SPCA-based method outperforms the conventional methods. Full article

(This article belongs to the Special Issue Intelligent and Cooperation Communication and Networking Technologies for IoT)

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24 pages, 6181 KiB

Open AccessArticle

Narrowband Interference Separation for Synthetic Aperture Radar via Sensing Matrix Optimization-Based Block Sparse Bayesian Learning

by Guojing Li, Wei Ye, Guochao Lao, Shuya Kong and Di Yan

Electronics 2019, 8(4), 458; https://doi.org/10.3390/electronics8040458 - 25 Apr 2019

Cited by 6 | Viewed by 3026

Abstract

High-resolution synthetic aperture radar (SAR) operating with a large bandwidth is subject to impacts from various kinds of narrowband interference (NBI) in complex electromagnetic environments. Recently, many radio frequency interference (RFI) suppression approaches for SAR based on sparse recovery have been proposed and [...] Read more.

High-resolution synthetic aperture radar (SAR) operating with a large bandwidth is subject to impacts from various kinds of narrowband interference (NBI) in complex electromagnetic environments. Recently, many radio frequency interference (RFI) suppression approaches for SAR based on sparse recovery have been proposed and demonstrated to outperform traditional ones in preserving the signal of interest (SOI) while suppressing the interference by exploiting their intrinsic structures. In particular, the joint recovery strategy of SOI and NBI with a cascaded dictionary, which eliminates the steps of NBI reconstruction and time-domain cancellation, can further reduce unnecessary system complexity. However, these sparsity-based approaches hardly work effectively for signals from an extended target or NBI with a certain bandwidth, since neither of them is sparse in a prescient domain. Moreover, sub-dictionaries corresponding to different components in the cascaded matrix are not strictly independent, which severely limits the performance of separated reconstruction. In this paper, we present an enhanced NBI separation algorithm for SAR via sensing matrix optimization-based block sparse Bayesian learning (SMO-BSBL) to solve these problems above. First, we extend the block sparse Bayesian learning framework to a complex-valued domain for the convenience of radar signal processing with lower computation complexity and modify it to deal with the separation problem of NBI in the contaminated echo. For the sake of improving the separated reconstruction performance, we propose a new block coherence measure by defining the external and internal block structure, which is used for optimizing the observation matrix. The optimized observation matrix is then employed to reconstruct SOI and NBI simultaneously under the modified BSBL framework, given a known and fixed cascaded dictionary. Numerical simulation experiments and comparison results demonstrate that the proposed SMO-BSBL is effective and superior to other advanced algorithms in NBI suppression for SAR. Full article

(This article belongs to the Special Issue Advanced Technology Related to Radar Signal, Imaging, and Radar Cross-Section Measurement)

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18 pages, 5862 KiB

Open AccessArticle

A Simplified Optimal-Switching-Sequence MPC with Finite-Control-Set Moving Horizon Optimization for Grid-Connected Inverter

by Longyun Kang, Jiancai Cheng, Bihua Hu, Xuan Luo and Jianbin Zhang

Electronics 2019, 8(4), 457; https://doi.org/10.3390/electronics8040457 - 25 Apr 2019

Cited by 6 | Viewed by 2888

Abstract

Optimal-switching-sequence model-predictive-control (OSS-MPC) strategy, a popular kind of continuous-control-set MPC (CCS-MPC), has been used to address the variable frequency of finite-control-set MPC (FCS-MPC). Since the digital signal processor (DSP) does not have a dedicated divider, it requires a large amount of computation for [...] Read more.

Optimal-switching-sequence model-predictive-control (OSS-MPC) strategy, a popular kind of continuous-control-set MPC (CCS-MPC), has been used to address the variable frequency of finite-control-set MPC (FCS-MPC). Since the digital signal processor (DSP) does not have a dedicated divider, it requires a large amount of computation for the division operations in OSS searching. Here, a simplified OSS-MPC absorbing the merits of FCS-MPC is proposed to reduce the computational burden of conventional OSS-MPC. The proposed method uses a novel cost function whose candidates are the finite center vectors instead of switching sequences, which can avoid duty cycle computation and convert the moving horizon optimization of CCS-MPC into that of FCS-MPC. Besides, the derivatives of the active and reactive powers are divided into the constant terms and variable terms. The constant terms are extracted from the cost function. Experimental and simulation results show that the computational amount of the proposed algorithm is only 36.34% of that of the conventional OSS-MPC. Meanwhile, the simplified OSS-MPC still maintains the excellent dynamic and steady state performance of conventional OSS-MPC. Full article

(This article belongs to the Section Power Electronics)

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17 pages, 7767 KiB

Open AccessArticle

Control of Internal Dynamics of Grid-Connected Modular Multilevel Converter Using an Integral Backstepping Controller

by Waqar Ud Din, Kamran Zeb, Muhammad Ishfaq, Saif Ul Islam, Imran Khan and Hee Je Kim

Electronics 2019, 8(4), 456; https://doi.org/10.3390/electronics8040456 - 24 Apr 2019

Cited by 10 | Viewed by 3901

Abstract

The modular multilevel converter (MMC) has significant applications in power systems due to its promising features, such as modularity, reliability, scalability, and low harmonic distortion. One of the challenges in the operation of MMC is to regulate the circulating current in its phase [...] Read more.

The modular multilevel converter (MMC) has significant applications in power systems due to its promising features, such as modularity, reliability, scalability, and low harmonic distortion. One of the challenges in the operation of MMC is to regulate the circulating current in its phase leg and sub module (SM) capacitor voltage. This paper presents the control of internal dynamics, i.e., circulating current and submodule capacitor voltage, of the MMC using an integral backstepping algorithm. The design of the controller is based on Lyapunov stability function. The backstepping control ensures the convergence of the error signal to zero. Additionally, the integral action in the control law increases the robustness and reliability of the system against the external disturbances and model uncertainties. Moreover, the integral term in the controller eliminates the residual steady-state error. The Lyapunov function-based design of the backstepping controller guarantees the convergence of circulating current as well as submodule capacitor voltage for any possible initial condition. Moreover, the performance of the proposed integral backstepping controller is compared with the proportional resonant (PR) controller. The proposed backstepping control scheme for three-phase MMC has been implemented in MATLAB/Simulink. Full article

(This article belongs to the Special Issue Power Quality in Smart Grids)

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25 pages, 2900 KiB

Open AccessArticle

Secure Intelligent Vehicular Network Using Fog Computing

by Samuel Kofi Erskine and Khaled M. Elleithy

Electronics 2019, 8(4), 455; https://doi.org/10.3390/electronics8040455 - 24 Apr 2019

Cited by 21 | Viewed by 5046

Abstract

VANET (vehicular ad hoc network) has a main objective to improve driver safety and traffic efficiency. The intermittent exchange of real-time safety message delivery in VANET has become an urgent concern due to DoS (denial of service) and smart and normal intrusions (SNI) [...] Read more.

VANET (vehicular ad hoc network) has a main objective to improve driver safety and traffic efficiency. The intermittent exchange of real-time safety message delivery in VANET has become an urgent concern due to DoS (denial of service) and smart and normal intrusions (SNI) attacks. The intermittent communication of VANET generates huge amount of data which requires typical storage and intelligence infrastructure. Fog computing (FC) plays an important role in storage, computation, and communication needs. In this research, fog computing (FC) integrates with hybrid optimization algorithms (OAs) including the Cuckoo search algorithm (CSA), firefly algorithm (FA), firefly neural network, and the key distribution establishment (KDE) for authenticating both the network level and the node level against all attacks for trustworthiness in VANET. The proposed scheme is termed “Secure Intelligent Vehicular Network using fog computing” (SIVNFC). A feedforward back propagation neural network (FFBP-NN), also termed the firefly neural, is used as a classifier to distinguish between the attacking vehicles and genuine vehicles. The SIVNFC scheme is compared with the Cuckoo, the FA, and the firefly neural network to evaluate the quality of services (QoS) parameters such as jitter and throughput. Full article

(This article belongs to the Special Issue Vehicular Networks and Communications)

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17 pages, 7213 KiB

Open AccessFeature PaperArticle

Modulation Strategy with a Minimal Number of Commutations for a Five-Level H-Bridge NPC Inverter

by Florent Becker, Ehsan Jamshidpour, Philippe Poure and Shahrokh Saadate

Electronics 2019, 8(4), 454; https://doi.org/10.3390/electronics8040454 - 23 Apr 2019

Cited by 2 | Viewed by 6640

Abstract

In this paper, a so-called OPTimized Pulse Width Modulation (OPT-PWM) strategy with a minimal number of commutations for a multilevel converter (MC) is proposed. The principle is based on the reduction of the number of switch commutations by removing the unnecessary ones for [...] Read more.

In this paper, a so-called OPTimized Pulse Width Modulation (OPT-PWM) strategy with a minimal number of commutations for a multilevel converter (MC) is proposed. The principle is based on the reduction of the number of switch commutations by removing the unnecessary ones for each voltage level transition. The OPT-PWM strategy is applied to a five-level H-Bridge Neutral Point Clamped (HB-5L-NPC) inverter. A specific block based on a state machine is added to conventional modulation techniques to perform the transitions from a given voltage level to another one via the best trajectory with a minimal number of commutations. The principle of this additional block can be applied to any modulation technique. In this paper, the proposed strategy is validated first by simulation and then through experimental tests. Full article

(This article belongs to the Special Issue Power Converters in Power Electronics)

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16 pages, 3754 KiB

Open AccessArticle

A Vehicle Type Dependent Car-following Model Based on Naturalistic Driving Study

by Ping Wu, Feng Gao and Keqiang Li

Electronics 2019, 8(4), 453; https://doi.org/10.3390/electronics8040453 - 23 Apr 2019

Cited by 19 | Viewed by 3899

Abstract

In this paper, a car-following model considering the preceding vehicle type is proposed to describe the longitudinal driving behavior closer to reality. Based on the naturalistic driving data sampled in real traffic for more than half a year, the relation between ego vehicle [...] Read more.

In this paper, a car-following model considering the preceding vehicle type is proposed to describe the longitudinal driving behavior closer to reality. Based on the naturalistic driving data sampled in real traffic for more than half a year, the relation between ego vehicle velocity and relative distance was analyzed by a multi-variable Gaussian Mixture model, from which it is found that the driver following behavior is influenced by the type of leading vehicle. Then a Hidden Markov model was designed to identify the vehicle type. This car-following model was trained and tested by using the naturalistic driving data. It can identify the leading vehicle type, i.e., passenger car, bus, and truck, and predict the ego vehicle velocity and relative distance based on a series of limited historical data in real time. The experimental validation results show that the identification accuracy of vehicle type under the static and dynamical conditions are 96.6% and 83.1%, respectively. Furthermore, comparing the results with the well-known collision avoidance model and intelligent driver model show that this new model is more accurate and can be used to design advanced driver assist systems for better adaptability to traffic conditions. Full article

(This article belongs to the Special Issue Intelligent Transportation Systems (ITS))

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5 pages, 168 KiB

Open AccessEditorial

Autonomous Control of Unmanned Aerial Vehicles

by Victor M. Becerra

Electronics 2019, 8(4), 452; https://doi.org/10.3390/electronics8040452 - 22 Apr 2019

Cited by 30 | Viewed by 5145

Abstract

Unmanned aerial vehicles (UAVs) are being increasingly used in different applications in both military and civilian domains [...] Full article

(This article belongs to the Special Issue Autonomous Control of Unmanned Aerial Vehicles)

11 pages, 5539 KiB

Open AccessArticle

Multi-Channel Optoelectronic Measurement System for Soil Nutrients Analysis

by Liuzheng Ma, Zhenfeng Li, Zephania Birech, Shixin Li, Yatao Yang, Wei Zhang and Jiandong Hu

Electronics 2019, 8(4), 451; https://doi.org/10.3390/electronics8040451 - 20 Apr 2019

Cited by 7 | Viewed by 3650

Abstract

To solve the problems that occur when farmers overuse chemical fertilizers, it is necessary to develop rapid and efficient portable measurement systems for the detection and quantification of nitrogen (N), phosphorus (P), and potassium (K) in soil. Challenges arise from the use of [...] Read more.

To solve the problems that occur when farmers overuse chemical fertilizers, it is necessary to develop rapid and efficient portable measurement systems for the detection and quantification of nitrogen (N), phosphorus (P), and potassium (K) in soil. Challenges arise from the use of currently available portable instruments which only have a few channels, namely measurement and the reference channels. We report on a home-built, multichannel, optoelectronic measurement system with automatically switching light sources for the detection of N, P, K content in soil samples. This optoelectronic measurement system consists of joint LED light sources with peak emission wavelengths of 405 nm, 660 nm, and 515 nm, a photodiode array, a circuit board with a microcontroller unit (MCU), and a liquid-crystal display (LCD) touch screen. The straightforward principle for rapid detection of the extractable nutrients (N, P, K) was well-established, and characterization of the designed measurement system was done. Using this multi-channel measurement system, available nutrients extracted from six soil samples could be measured simultaneously. The absorbance compensation, concentration calibration, and nutrition measurements were performed automatically to achieve high consistency across six channels. The experimental results showed that the cumulative relative standard deviations of 1.22%, 1.27%, and 1.00% were obtained from six channels with known concentrations of standard solutions, respectively. The coefficients of correlation for the detection of extracted nutrients of N, P, K content in soil samples using both the proposed method and conventional lab-based method were 0.9010, 0.9471, and 0.8923, respectively. Experimental results show that this optoelectronic measurement system can perform the measurement of N, P, K contents of six soil samples simultaneously and may be used as an actual tool in determining nutrients in soil samples with an improvement in detection efficiency. Full article

(This article belongs to the Special Issue Recent Advances in Biometrics and its Applications)

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19 pages, 447 KiB

Open AccessArticle

A Privacy-Preserving Authentication and Key Agreement Scheme with Deniability for IoT

by Yousheng Zhou, Tong Liu, Fei Tang, Feng Wang and Magara Tinashe

Electronics 2019, 8(4), 450; https://doi.org/10.3390/electronics8040450 - 19 Apr 2019

Cited by 10 | Viewed by 3333

Abstract

User authentication for the Internet of Things (IoT) is a vital measure as it consists of numerous unattended connected devices and sensors. For security, only the user authenticated by the gateway node can access the real-time data gathered by sensor nodes. In this [...] Read more.

User authentication for the Internet of Things (IoT) is a vital measure as it consists of numerous unattended connected devices and sensors. For security, only the user authenticated by the gateway node can access the real-time data gathered by sensor nodes. In this article, an efficient privacy-preserving authentication and key agreement scheme for IoT is developed which enables the user, the gateway node and sensor nodes to authenticate with each other. Only the trusted gateway node can determine the real identity of user; however, no other entities can get information about user’ identity by just intercepting all exchanged messages during authentication phase. The gateway cannot prove the received messages from the sender to a third party, and thus preserving the privacy of the sender. The correctness of the proposed scheme is proved to be feasible by using BAN logic, and its security is proved under the random oracle model. The execution time of the proposed scheme is evaluated and compared with existing similar schemes, and the results demonstrate that our proposed scheme is more efficient and applicable for IoT applications. Full article

(This article belongs to the Special Issue IoT in 5G)

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17 pages, 6781 KiB

Open AccessArticle

A Capacitor Voltage Balancing Approach Based on Mapping Strategy for MMC Applications

by Mattia Ricco, Laszlo Mathe, Manel Hammami, Francesco Lo Franco, Claudio Rossi and Remus Teodorescu

Electronics 2019, 8(4), 449; https://doi.org/10.3390/electronics8040449 - 19 Apr 2019

Cited by 12 | Viewed by 3664

Abstract

This paper proposes a new strategy to achieve balanced capacitor voltages in modular multilevel converters. Among the possible solutions, centralized arm control approaches are often adopted. These methods require a balancing technique based on a sorted list of the sub-modules according to their [...] Read more.

This paper proposes a new strategy to achieve balanced capacitor voltages in modular multilevel converters. Among the possible solutions, centralized arm control approaches are often adopted. These methods require a balancing technique based on a sorted list of the sub-modules according to their capacitor voltages. In order to achieve the aforementioned sorted list, different algorithms have been proposed in literature, such as: Sorting algorithms, max/min approaches, etc. However, the sorting algorithms require a long execution time, while the max/min approaches affect the converter dynamic response during faults. To overcome these issues, a new mapping strategy providing a quasi-sorted list is proposed in this paper. The suggested method is compared in simulation with both the classical bubble sorting algorithm, and the max/min method during both normal and faulty conditions. Moreover, the three methods have been implemented in a Xilinx Zynq-7000 System-on-Chip (SoC) device, in order to analyze the corresponding execution time and the required computational effort. Hardware-in-the-loop results are presented for demonstrating the superior performance of the proposed balancing strategy. Full article

(This article belongs to the Section Power Electronics)

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14 pages, 2755 KiB

Open AccessArticle

Performance Analysis of a User Selection Protocol in Cooperative Networks with Power Splitting Protocol-Based Energy Harvesting Over Nakagami-m/Rayleigh Channels

by Tan N. Nguyen, Minh Tran, Thanh-Long Nguyen, Duy-Hung Ha and Miroslav Voznak

Electronics 2019, 8(4), 448; https://doi.org/10.3390/electronics8040448 - 19 Apr 2019

Cited by 33 | Viewed by 3272

Abstract

In this work, the system performance analysis of cooperative networks with power splitting protocol-based energy harvesting (EH) over Nakagami-m/Rayleigh channels is proposed. The exact-form expressions of the outage probability (OP) and ergodic capacity (EC) is demonstrated and derived. Using the proposed probabilistic models [...] Read more.

In this work, the system performance analysis of cooperative networks with power splitting protocol-based energy harvesting (EH) over Nakagami-m/Rayleigh channels is proposed. The exact-form expressions of the outage probability (OP) and ergodic capacity (EC) is demonstrated and derived. Using the proposed probabilistic models for wireless channels, we derive OP and EC as a research result. Finally, we conduct Monte Carlo simulations to verify a system performance analysis of the proposed system. The research results demonstrate the effectiveness of EH in the network over Nakagami-m/Rayleigh channels. Full article

(This article belongs to the Section Networks)

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18 pages, 16082 KiB

Open AccessArticle

Rolling 3D Laplacian Pyramid Video Fusion

by Rade Pavlović and Vladimir Petrović

Electronics 2019, 8(4), 447; https://doi.org/10.3390/electronics8040447 - 19 Apr 2019

Viewed by 3857

Abstract

In this paper, we present a novel algorithm for video fusion of multi-sensor sequences applicable to real-time night vision systems. We employ the Laplacian pyramid fusion of a block of successive frames to add temporal robustness to the fused result. For the fusion [...] Read more.

In this paper, we present a novel algorithm for video fusion of multi-sensor sequences applicable to real-time night vision systems. We employ the Laplacian pyramid fusion of a block of successive frames to add temporal robustness to the fused result. For the fusion rule, we first group high and low frequency levels of the decomposed frames in the block from both input sensor sequences. Then, we define local space-time energy measure to guide the selection based fusion process in a manner that achieves spatio-temporal stability. We demonstrate our approach on several well-known multi-sensor video fusion examples with varying contents and target appearance and show its advantage over conventional video fusion approaches. Computational complexity of the proposed methods is kept low by the use of simple linear filtering that can be easily parallelised for implementation on general-purpose graphics processing units (GPUs). Full article

(This article belongs to the Special Issue Signal Processing and Analysis of Electrical Circuit)

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13 pages, 4437 KiB

Open AccessFeature PaperArticle

Using Different Ions in the Hydrothermal Method to Enhance the Photoluminescence Properties of Synthesized ZnO-Based Nanowires

by Ya-Fen Wei, Wen-Yaw Chung, Cheng-Fu Yang, Jei-Ru Shen and Chih-Cheng Chen

Electronics 2019, 8(4), 446; https://doi.org/10.3390/electronics8040446 - 18 Apr 2019

Cited by 6 | Viewed by 3121

Abstract

ZnO films with a thickness of ~200 nm were deposited on SiO₂/Si substrates as the seed layer. Then Zn(NO₃)₂-6H₂O and C₆H₁₂N₄ containing different concentrations of Eu(NO₃)₂-6H [...] Read more.

ZnO films with a thickness of ~200 nm were deposited on SiO₂/Si substrates as the seed layer. Then Zn(NO₃)₂-6H₂O and C₆H₁₂N₄ containing different concentrations of Eu(NO₃)₂-6H₂O or In(NO₃)₂-6H₂O were used as precursors, and a hydrothermal process was used to synthesize pure ZnO as well as Eu-doped and In-doped ZnO nanowires at different synthesis temperatures. X-ray diffraction (XRD) was used to analyze the crystallization properties of the pure ZnO and the Eu-doped and In-doped ZnO nanowires, and field emission scanning electronic microscopy (FESEM) was used to analyze their surface morphologies. The important novelty in our approach is that the ZnO-based nanowires with different concentrations of Eu³⁺ and In³⁺ ions could be easily synthesized using a hydrothermal process. In addition, the effect of different concentrations of Eu³⁺ and In³⁺ ions on the physical and optical properties of ZnO-based nanowires was well investigated. FESEM observations found that the undoped ZnO nanowires could be grown at 100 °C. The third novelty is that we could synthesize the Eu-doped and In-doped ZnO nanowires at temperatures lower than 100 °C. The temperatures required to grow the Eu-doped and In-doped ZnO nanowires decreased with increasing concentrations of Eu³⁺ and In³⁺ ions. XRD patterns showed that with the addition of Eu³⁺ (In³⁺), the diffraction intensity of the (002) peak slightly increased with the concentration of Eu³⁺ (In³⁺) ions and reached a maximum at 3 (0.4) at%. We show that the concentrations of Eu³⁺ and In³⁺ ions have considerable effects on the synthesis temperatures and photoluminescence properties of Eu³⁺-doped and In³⁺-doped ZnO nanowires. Full article

(This article belongs to the Special Issue Intelligent Electronic Devices)

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8 pages, 3772 KiB

Open AccessArticle

Area-Efficient Embedded Resistor-Triggered SCR with High ESD Robustness

by Fei Hou, Feibo Du, Kai Yang, Jizhi Liu and Zhiwei Liu

Electronics 2019, 8(4), 445; https://doi.org/10.3390/electronics8040445 - 18 Apr 2019

Cited by 2 | Viewed by 4196

Abstract

The trigger voltage of the direct-connected silicon-controlled rectifier (DCSCR) was effectively reduced for electrostatic discharge (ESD) protection. However, a deep NWELL (DNW) is required to isolate PWELL from P-type substrate (PSUB) in DCSCR, which wastes part of the layout area. An area-efficient embedded [...] Read more.

The trigger voltage of the direct-connected silicon-controlled rectifier (DCSCR) was effectively reduced for electrostatic discharge (ESD) protection. However, a deep NWELL (DNW) is required to isolate PWELL from P-type substrate (PSUB) in DCSCR, which wastes part of the layout area. An area-efficient embedded resistor-triggered silicon-controlled rectifier (ERTSCR) is proposed in this paper. As verified in a 0.3-μm CMOS process, the proposed ERTSCR exhibits lower triggering voltage due to series diode chains and embedded deep n-well resistor in the trigger path. Additionally, the proposed ERTSCR has a failure current of more than 5 A and a corresponding HBM ESD robustness of more than 8 KV. Furthermore, compared with the traditional DCSCR, to sustain the same ESD protection capability, the proposed ERTSCR will consume 10% less silicon area by fully utilizing the lateral dimension in the deep n-well extension region, while the proposed ERTSCR has a larger top metal width. Full article

(This article belongs to the Section Microelectronics)

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14 pages, 1350 KiB

Open AccessFeature PaperArticle

Early Output Quasi-Delay-Insensitive Array Multipliers

by Padmanabhan Balasubramanian, Douglas Maskell, R. T. Naayagi and Nikos Mastorakis

Electronics 2019, 8(4), 444; https://doi.org/10.3390/electronics8040444 - 18 Apr 2019

Cited by 5 | Viewed by 2832

Abstract

Multiplication is a widely used arithmetic operation in microprocessing and digital signal processing applications, and multiplication is realized using a multiplier. This article presents the quasi-delay-insensitive (QDI) early output versions of recently reported indicating asynchronous array multipliers. Delay-insensitive dual-rail encoding is used for [...] Read more.

Multiplication is a widely used arithmetic operation in microprocessing and digital signal processing applications, and multiplication is realized using a multiplier. This article presents the quasi-delay-insensitive (QDI) early output versions of recently reported indicating asynchronous array multipliers. Delay-insensitive dual-rail encoding is used for data representation and processing, and 4-phase return-to-zero (RTZ) and return-to-one (RTO) handshake protocols are used for data communication. Many QDI array multipliers were realized using a 32/28 nm complementary metal oxide semiconductor (CMOS) technology. Compared to the optimum indicating array multiplier, the proposed optimum early output array multiplier achieves a 6.2% reduction in cycle time and a 7.4% reduction in power-cycle time product (PCTP) with respect to RTZ handshaking, and a 7.6% reduction in cycle time and an 8.8% reduction in PCTP with respect to RTO handshaking without an increase in the area. The simulation results also convey that the RTO handshaking is preferable to the RTZ handshaking for the optimum implementation of QDI array multipliers. Full article

(This article belongs to the Section Microelectronics)

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21 pages, 3503 KiB

Open AccessArticle

A Hierarchical Cooperative Mission Planning Mechanism for Multiple Unmanned Aerial Vehicles

by Zhe Zhao, Jian Yang, Yifeng Niu, Yu Zhang and Lincheng Shen

Electronics 2019, 8(4), 443; https://doi.org/10.3390/electronics8040443 - 18 Apr 2019

Cited by 13 | Viewed by 3431

Abstract

In this paper, the cooperative multi-task online mission planning for multiple Unmanned Aerial Vehicles (UAVs) is studied. Firstly, the dynamics of unmanned aerial vehicles and the mission planning problem are studied. Secondly, a hierarchical mechanism is proposed to deal with the complex multi-UAV [...] Read more.

In this paper, the cooperative multi-task online mission planning for multiple Unmanned Aerial Vehicles (UAVs) is studied. Firstly, the dynamics of unmanned aerial vehicles and the mission planning problem are studied. Secondly, a hierarchical mechanism is proposed to deal with the complex multi-UAV multi-task mission planning problem. In the first stage, the flight paths of UAVs are generated by the Dubins curve and B-spline mixed method, which are defined as “CBC)” curves, where “C” stands for circular arc and “B” stands for B-spline segment. In the second stage, the task assignment problem is solved as multi-base multi-traveling salesman problem, in which the “CBC” flight paths are used to estimate the trajectory costs. In the third stage, the flight trajectories of UAVs are generated by using Gaussian pseudospectral method (GPM). Thirdly, to improve the computational efficiency, the continuous and differential initial trajectories are generated based on the “CBC” flight paths. Finally, numerical simulations are presented to demonstrate the proposed approach, the designed initial solution search algorithm is compared with existing methods. These results indicate that the proposed hierarchical mission planning method can produce satisfactory mission planning results efficiently. Full article

(This article belongs to the Special Issue Motion Planning and Control for Robotics)

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21 pages, 7947 KiB

Open AccessArticle

A Novel Approach towards Resource Auto-Registration and Discovery of Embedded Systems Based on DNS

by Azimbek Khudoyberdiev, Wenquan Jin and DoHyeun Kim

Electronics 2019, 8(4), 442; https://doi.org/10.3390/electronics8040442 - 17 Apr 2019

Cited by 9 | Viewed by 4635

Abstract

The Internet of Things (IoT) is expected to deliver a whole range of new services to all parts of our society, and improve the way we work and live. The challenges within the Internet of Things are often related to interoperability, device resource [...] Read more.

The Internet of Things (IoT) is expected to deliver a whole range of new services to all parts of our society, and improve the way we work and live. The challenges within the Internet of Things are often related to interoperability, device resource constraints, a device to device connection and security. One of the essential elements of identification for each Internet of Things devices is the naming system and addresses. With this naming system, Internet of Things devices can be able to be discoverable by users. In this paper, we propose the IoT resource auto-registration and accessing indoor services based on Domain Name System (DNS) in the Open Connectivity Foundation (OCF) environment. We have used the Internet of Things Platform and DNS server for IoT Resource auto-registration and discovery in the Internet Protocol version 4 (IPv4). An existing system called Domain Name Auto-Registration in Internet Protocol version 6 can be used for Internet of Things devices for auto-registration and resource discovery. However, this system is not acceptable in the existing internet networks, because the highest percentage of the networks on the Internet are configured in Internet Protocol version 4. Through the proposed auto-registration system, clients can be able to discover the resources and access the services in the OCF network. Constrained Application Protocol (CoAP) is utilized for the IoT device auto-registration and accessing the services in the OCF network. Full article

(This article belongs to the Section Networks)

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18 pages, 5248 KiB

Open AccessArticle

WSMS: Wearable Stress Monitoring System Based on IoT Multi-Sensor Platform for Living Sheep Transportation

by Yan Cui, Mengjie Zhang, Jun Li, Hailing Luo, Xiaoshuan Zhang and Zetian Fu

Electronics 2019, 8(4), 441; https://doi.org/10.3390/electronics8040441 - 17 Apr 2019

Cited by 23 | Viewed by 7089

Abstract

Farming herdsmen, sheep dealers, and veterinarians are increasingly interested in continuously monitoring sheep basic physiological characteristics (such as the heart rate and skin temperature) outside the laboratory environment, with the aim of identifying the physiological links between stress, uncomfortable, excitement, and other pathological [...] Read more.

Farming herdsmen, sheep dealers, and veterinarians are increasingly interested in continuously monitoring sheep basic physiological characteristics (such as the heart rate and skin temperature) outside the laboratory environment, with the aim of identifying the physiological links between stress, uncomfortable, excitement, and other pathological states. This paper proposes a non-invasive Wearable Stress Monitoring System (WSMS) with PhotoPlethysmoGram (PPG), Infrared Temperature Measurement (ITM), and Inertial Measurement Units (IMU) that aimed to remotely and continuously monitor the stress signs of sheep during transportation. The purpose of this study was implemented by following the multi-dimensional sensing platform to identify more pressure information. The designed WSMS showed sufficient robustness in recording and transmitting sensing data of physiology and environment during transport. The non-contact and non-destructive monitoring method that was proposed in this paper was helpful in minimizing the effects of sheep stress load. Full article

(This article belongs to the Special Issue Wearable Electronic Devices)

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11 pages, 3842 KiB

Open AccessArticle

A Compact Wideband SIW Bandpass Filter with Wide Stopband and High Selectivity

by Lei Huang and Naichang Yuan

Electronics 2019, 8(4), 440; https://doi.org/10.3390/electronics8040440 - 17 Apr 2019

Cited by 12 | Viewed by 5348

Abstract

A novel method to design a wideband substrate integrated waveguide (SIW) bandpass filter (BPF) with compact size, wide stopband and high selectivity is presented. In this method some unique electromagnetic band-gap (EBG) cells are periodically etched on the top layer of SIW to [...] Read more.

A novel method to design a wideband substrate integrated waveguide (SIW) bandpass filter (BPF) with compact size, wide stopband and high selectivity is presented. In this method some unique electromagnetic band-gap (EBG) cells are periodically etched on the top layer of SIW to realize a wide passband propagating below the equivalent waveguide cutoff frequency. By changing the configuration of EBG cells, undesired harmonics in upper stopband can be suppressed and a wideband BPF with wide stopband can be obtained. By symmetrically loading two complementary split ring resonators (CSRRs) on the tapered gradient lines of the input/output ports, a transmission zero near the passband can be introduced, and it makes the frequency selectivity of upper sideband improve significantly. As a verification, a wideband SIW BPF with a 3.02 GHz absolute bandwidth (ABW) and a 64.7% fractional bandwidth (FBW) centered at 4.67 GHz is designed, simulated, manufactured, and measured. The results of the experiment and simulation are in good agreement. Full article

(This article belongs to the Section Microwave and Wireless Communications)

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