Electronics

19 pages, 7007 KiB

Open AccessArticle

Power Efficient Fully Differential Bulk Driven OTA for Portable Biomedical Application

by Saleha Bano, Ghous Bakhsh Narejo and Syed Muhammad Usman Ali Shah

Electronics 2018, 7(3), 41; https://doi.org/10.3390/electronics7030041 - 20 Mar 2018

Cited by 17 | Viewed by 7983

This paper presents a power efficient, bulk driven, source degenerated fully differential operational transconductance amplifier (OTA), operating in the subthreshold region. The input part of the OTA consists of a bulk driven source degenerated differential pair and cross coupled transistors to improve the [...] Read more.

This paper presents a power efficient, bulk driven, source degenerated fully differential operational transconductance amplifier (OTA), operating in the subthreshold region. The input part of the OTA consists of a bulk driven source degenerated differential pair and cross coupled transistors to improve the linearity of OTA. It consists of a bulk driven pair to reduce the supply voltage and to improve the linearity. The proposed fully differential OTA has utilized self-cascode current mirror loads which increases the output impedance and hence the overall intrinsic gain. A subthreshold region is adopted to reduce the power consumption of the circuit. For a 200 mVpp sinusoidal input at 100 Hz, a total harmonic distortion (THD) of −58.56 dB is achieved. The gain, gain bandwidth (GBW), phase margin (PM) and gain margin (GM) values obtained were 48.4 dB, 3.1 KHz, 80° and 19.01 dB, respectively. The common mode rejection ratio (CMRR), power supply rejection ratio (PSRR) and slew rate +/− values were 146.3 dB, 83 dB and 99.56/100 V/ms, respectively. The circuit is capable of operating under a supply voltage of 0.8 V with a power consumption of 59.04 nW, which proves that the circuit is suitable for portable biomedical devices. The proposed circuit is simulated in CADENCE environment virtuoso using LFoundry 150 nm Complementary metal oxide semiconductor (CMOS) process technology. Full article

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16 pages, 1037 KiB

Open AccessArticle

DoA and DoD Estimation and Hybrid Beamforming for Radar-Aided mmWave MIMO Vehicular Communication Systems

by Zhimin Chen, Zhenxin Cao, Xinyi He, Yi Jin, Jingchao Li and Peng Chen

Electronics 2018, 7(3), 40; https://doi.org/10.3390/electronics7030040 - 18 Mar 2018

Cited by 20 | Viewed by 7712

Abstract

In millimeter wave (mmWave) communications, the feature of relatively large signal absorption and directional transmission render new challenges for wireless communications and signal processing. To further improve the performance of mmWave communications, a novel radar-aided mmWave communication (RAMC) approach is proposed, which can [...] Read more.

In millimeter wave (mmWave) communications, the feature of relatively large signal absorption and directional transmission render new challenges for wireless communications and signal processing. To further improve the performance of mmWave communications, a novel radar-aided mmWave communication (RAMC) approach is proposed, which can be used in vehicular communications. There are two parts in the proposed RAMC system, including the radar subsystem and the mmWave communication subsystem. In the radar subsystem, the bistatic co-prime multi-input and multi-output (MIMO) arrays are considered. With the radar antenna arrays, both the directions of departure (DoD) and the directions of arrival (DoA) are estimated. Additionally, the compressed sensing (CS)-based method is proposed to obtain the target positions. Using the estimated angle and position information, the channel estimation and feedback link of the mmWave communication subsystem can be eliminated. Moreover, a hybrid beamforming algorithm is proposed in the mmWave communication subsystem, which can overcome the shortage of the analog-only beamforming. Simulation results show that the better estimation performance can be achieved by the bistatic co-prime MIMO arrays than that by the traditional uniform linear arrays (ULA), and with the radar aided, the mmWave communication subsystem can reduce the beam search time, and the cell discovery time is improved significantly. Full article

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11 pages, 5905 KiB

Open AccessArticle

New Wafer Alignment Process Using Multiple Vision Method for Industrial Manufacturing

by Jongwon KIM

Electronics 2018, 7(3), 39; https://doi.org/10.3390/electronics7030039 - 11 Mar 2018

Cited by 9 | Viewed by 15266

Abstract

In semiconductor manufacturing, wafer aligners have been widely used, such as the conventional alignment method using a Charge Coupled Device (CCD) transmission sensor to detect the notch or flat in a wafer. This paper presents a proposed vision aligner using a vision method [...] Read more.

In semiconductor manufacturing, wafer aligners have been widely used, such as the conventional alignment method using a Charge Coupled Device (CCD) transmission sensor to detect the notch or flat in a wafer. This paper presents a proposed vision aligner using a vision method that can be installed in the wafer and plate bonding machine for mass production. The vision system, which uses three cameras to perform wafer alignment of position and rotation, detects wafer face side and ultraviolet (UV) tape on the target wafer and plate. It can be utilized for the alignment process of wafers and ceramic plate bonding. Using the vision method, the aligner could reduce the process steps and time required for wafer bonding, as well as unexpected problems caused by the workers during manufacturing. The system was applied in the mass production field to verify its performance. Full article

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18 pages, 5926 KiB

Open AccessArticle

Development of EOG-Based Human Computer Interface (HCI) System Using Piecewise Linear Approximation (PLA) and Support Vector Regression (SVR)

by Jung-Jin Yang, Gyeong Woo Gang and Tae Seon Kim

Electronics 2018, 7(3), 38; https://doi.org/10.3390/electronics7030038 - 9 Mar 2018

Cited by 13 | Viewed by 6399

Abstract

Electrooculogram (EOG)-based human-computer interfaces (HCIs) are widely researched and considered to be a good HCI option for disabled people. However, conventional systems can only detect eye direction or blinking action. In this paper, we developed a bio-signal-based HCI that can quantitatively estimate the [...] Read more.

Electrooculogram (EOG)-based human-computer interfaces (HCIs) are widely researched and considered to be a good HCI option for disabled people. However, conventional systems can only detect eye direction or blinking action. In this paper, we developed a bio-signal-based HCI that can quantitatively estimate the horizontal position of eyeball. A designed bio-signal acquisition system can measure EOG and temporalis electromyogram (EMG) signals simultaneously without additional electrodes. For real-time processing for practical application, modified sliding window algorithms are designed and applied for piecewise linear approximation (PLA). To find the eyeball position, support vector regression (SVR) is applied as a curve-fitting model. The average tracking error for target circle with a diameter of 3 cm showed only 1.4 cm difference on the screen with a width of 51 cm. A developed HCI system can perform operations similar to dragging and dropping used in a mouse interface in less than 5 s with only eyeball movement and bite action. Compare to conventional EOG-based HCI that detects the position of the eyeball only in 0 and 1 levels, a developed system can continuously track the eyeball position in less than 0.2 s. In addition, compared to conventional EOG-based HCI, the reduced number of electrodes can enhance the interface usability. Full article

(This article belongs to the Special Issue Open-Source Electronics Platforms: Development and Applications)

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13 pages, 1516 KiB

Open AccessArticle

Human Posture Identification Using a MIMO Array

by Dai Sasakawa, Naoki Honma, Takeshi Nakayama and Shoichi Iizuka

Electronics 2018, 7(3), 37; https://doi.org/10.3390/electronics7030037 - 8 Mar 2018

Cited by 16 | Viewed by 5449

Abstract

The elderly are constantly in danger of falling and injuring themselves without anyone realizing it. A safety-monitoring system based on microwaves can ease these concerns. The authors have proposed safety-monitoring systems that use multiple-input multiple-output (MIMO) radar to localize persons by capturing their [...] Read more.

The elderly are constantly in danger of falling and injuring themselves without anyone realizing it. A safety-monitoring system based on microwaves can ease these concerns. The authors have proposed safety-monitoring systems that use multiple-input multiple-output (MIMO) radar to localize persons by capturing their biological activities such as respiration. However, our studies to date have focused on localization, which is easier to achieve than an estimation of human postures. This paper proposes a human posture identification scheme based on height and a Doppler radar cross section (RCS) as estimated by a MIMO array. This scheme allows smart home applications to dispense with contact and wearable devices. Experiments demonstrate that this method can identify the supine position (i.e., after a fall) with 100% accuracy, and the average identification rate is 95.0%. Full article

(This article belongs to the Special Issue Data Processing and Wearable Systems for Effective Human Monitoring)

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23 pages, 3554 KiB

Open AccessArticle

Analysis of Network Attack and Defense Strategies Based on Pareto Optimum

by Yang Sun, Wei Xiong, Zhonghua Yao, Krishna Moniz and Ahmed Zahir

Electronics 2018, 7(3), 36; https://doi.org/10.3390/electronics7030036 - 7 Mar 2018

Cited by 9 | Viewed by 5432

Abstract

Improving network security is a difficult problem that requires balancing several goals, such as defense cost and need for network efficiency, to achieve proper results. Modeling the network as a game and using optimization problems to select the best move in such a [...] Read more.

Improving network security is a difficult problem that requires balancing several goals, such as defense cost and need for network efficiency, to achieve proper results. Modeling the network as a game and using optimization problems to select the best move in such a game can assist network administrators in determining an ideal defense strategy. However, most approaches for determining optimal game solutions tend to focus on either single objective games or merely scalarize the multiple objectives to a single of objective. In this paper, we devise a method for modeling network attacks in a zero-sum multi-objective game without scalarizing the objectives. We use Pareto Fronts to determine the most harmful attacks and Pareto Optimization to find the best defense against those attacks. By determining the optimal solutions through those means, we allow network administrators to make the final defense decision from a much smaller set of defense options. The included experiment uses minimum distance as selection method and compares the results with a minimax algorithm for the determination of the Nash Equilibrium. The proposed algorithm should help network administrators in search of a hands-on method of improving network security. Full article

(This article belongs to the Special Issue Safe and Secure Embedded Systems)

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2 pages, 546 KiB

Open AccessEditorial

2018 Electronics Travel Awards for Postdoctoral Fellows and PhD Students Announcement

by Mostafa Bassiouni and Electronics Editorial Office

Electronics 2018, 7(3), 35; https://doi.org/10.3390/electronics7030035 - 7 Mar 2018

Viewed by 4784

Abstract

Electronics launched, in 2018, the Travel Awards for Postdoctoral Fellows and PhD Students for the first time.[...]
Full article

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20 pages, 1639 KiB

Open AccessArticle

Comparative Analysis of Si- and GaN-Based Single-Phase Transformer-Less PV Grid-Tied Inverter

by Khaled Alatawi, Fahad Almasoudi, Mahesh Manandhar and Mohammad Matin

Electronics 2018, 7(3), 34; https://doi.org/10.3390/electronics7030034 - 7 Mar 2018

Cited by 10 | Viewed by 6676

Abstract

Recently, the interest in grid-tied PV transformer-less inverters has increased rapidly, because of their higher efficiency and lower cost compared to traditional line transformer inverters. This paper presents a new modified transformer-less topology derived from H5 inverter, and provides a detailed comparison between [...] Read more.

Recently, the interest in grid-tied PV transformer-less inverters has increased rapidly, because of their higher efficiency and lower cost compared to traditional line transformer inverters. This paper presents a new modified transformer-less topology derived from H5 inverter, and provides a detailed comparison between the use of GaN and Si devices for the proposed topology. Detailed operation modes, inverter structure and switching strategy of the proposed topology are presented. Datasheet information, conduction losses, switching losses, and heat sink requirements are studied and analyzed to provide an accurate comparison between GaN and Si power devices for the proposed topology operating at unity power factor. The results show that, GaN power devices significantly reduce the power losses in the system, which consequently allow a significant increase in either inverter power rating or switching frequency. Thus, the use of GaN power devices for the proposed inverter can be more appealing and cost-effective approach. Full article

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18 pages, 1573 KiB

Open AccessArticle

Automated Scalable Address Generation Patterns for 2-Dimensional Folding Schemes in Radix-2 FFT Implementations

by Felipe Minotta, Manuel Jimenez and Domingo Rodriguez

Electronics 2018, 7(3), 33; https://doi.org/10.3390/electronics7030033 - 3 Mar 2018

Cited by 5 | Viewed by 5466

Abstract

Hardware-based implementations of the Fast Fourier Transform (FFT) are highly regarded as they provide improved performance characteristics with respect to software-based sequential solutions. Due to the high number of operations involved in calculations, most hardware-based FFT approaches completely or partially fold their structure [...] Read more.

Hardware-based implementations of the Fast Fourier Transform (FFT) are highly regarded as they provide improved performance characteristics with respect to software-based sequential solutions. Due to the high number of operations involved in calculations, most hardware-based FFT approaches completely or partially fold their structure to achieve an efficient use of resources. A folding operation requires a permutation block, which is typically implemented using either permutation logic or address generation. Addressing schemes offer resource-efficient advantages when compared to permutation logic. We propose a systematic and scalable procedure for generating permutation-based address patterns for any power-of-2 transform size algorithm and any folding factor in FFT cores. To support this procedure, we develop a mathematical formulation based on Kronecker products algebra for address sequence generation and data flow pattern in FFT core computations, a well-defined procedure for scaling address generation schemes, and an improved approach in the overall automated generation of FFT cores. We have also performed an analysis and comparison of the proposed hardware design performance with respect to a similar strategy reported in the recent literature in terms of clock latency, performance, and hardware resources. Evaluations were carried on a Xilinx Virtex-7 FPGA (Field Programmable Gate Array) used as implementation target. Full article

(This article belongs to the Special Issue Real-Time Embedded Systems)

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15 pages, 6512 KiB

Open AccessFeature PaperArticle

Performance Comparison of Geobroadcast Strategies for Winding Roads

by Edgar Talavera, José J. Anaya, Oscar Gómez, Felipe Jiménez and José E. Naranjo

Electronics 2018, 7(3), 32; https://doi.org/10.3390/electronics7030032 - 3 Mar 2018

Cited by 8 | Viewed by 5194

Abstract

Vehicle-to-X (V2X) communications allow real-time information sharing between vehicles and Roadside Units (RSUs). These kinds of technologies allow for the improvement of road safety and can be used in combination with other systems. Advanced Driver Assistance Systems (ADAS) are an example and can [...] Read more.

Vehicle-to-X (V2X) communications allow real-time information sharing between vehicles and Roadside Units (RSUs). These kinds of technologies allow for the improvement of road safety and can be used in combination with other systems. Advanced Driver Assistance Systems (ADAS) are an example and can be used along with V2X communications to improve performance and enable Cooperative Systems. A key element of vehicular communications is that the information transmitted through the network is always linked to a GPS position related to origin and destination (GeoNetworking protocol) in order to adjust the data broadcast to the dynamic road environment needs. In this paper, we present the implementation and development of Institute for Automobile Research (INSIA) V2X communication modules that follow the European vehicular networking standards in a close curve in a winding road where poor visibility causes a risk to the safety of road users. The technology chosen to support these communications is ETSI ITS-G5, which has the capability to enable specific services that support GeoNetworking protocols, specifically the Geobroadcast (GBC) algorithm. These functionalities have been implemented and validated in a real environment in order to demonstrate the performance of the communication devices in real V2V (Vehicle-to-Vehicle) and V2I (Vehicle-to-Infrastructure) situations. GBC messages are also compared with two different configurations of emission area. A comparison with/without RSU modules in critical areas of the road with previous knowledge of the road cartography has also been made. Full article

(This article belongs to the Special Issue Machine Learning and Embedded Computing in Advanced Driver Assistance Systems (ADAS))

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11 pages, 2386 KiB

Open AccessArticle

Multi-Peak Double-Dwell GPS Weak Signal Acquisition Method and VLSI Implementation for Energy-Constrained Applications

by Zhen Wang, Hengfeng Zhang, Min Wang, Xinning Liu, Yuan Zhuang, Hao Cai, Jun Yang and Longxing Shi

Electronics 2018, 7(3), 31; https://doi.org/10.3390/electronics7030031 - 1 Mar 2018

Cited by 5 | Viewed by 5012

Abstract

Power consumption of Global Positioning System (GPS) acquisition is a great challenge for energy-constrained applications. In this work, a metric named acquisition mean computation overhead is proposed to measure the energy cost. A novel multi-peak double-dwell (MP/DD) acquisition method for GPS weak signal [...] Read more.

Power consumption of Global Positioning System (GPS) acquisition is a great challenge for energy-constrained applications. In this work, a metric named acquisition mean computation overhead is proposed to measure the energy cost. A novel multi-peak double-dwell (MP/DD) acquisition method for GPS weak signal is proposed. It adopts multi-peak correlation results as candidates in the first acquisition dwell and selects the largest one as the final acquisition result in the second acquisition dwell. Theoretical analysis and numerical simulation are presented in detail. Meanwhile, the very-large-scale integration (VLSI) implementation of coarse- and fine-grained acquisition engines applied to the proposed method is done. The detection probability and acquisition mean computation overhead are simulated using the Monte-Carlo method, and its mean acquisition power is tested with an actual chip. We fabricated the GPS signal acquisition engine with a 40 nm complementary metal oxide semiconductor (CMOS) process. The simulation results demonstrate that detection probability is promoted from 18% to 67% when signal power is equal to 23 dB/Hz. The acquisition mean computation overhead is reduced greatly by 64%. Measurement results show that the energy consumption of this design is only 21.5% of the conventional double-dwell/maximum (DD/MAX) method. Full article

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21 pages, 456 KiB

Open AccessReview

Review of Polynomial Chaos-Based Methods for Uncertainty Quantification in Modern Integrated Circuits

by Arun Kaintura, Tom Dhaene and Domenico Spina

Electronics 2018, 7(3), 30; https://doi.org/10.3390/electronics7030030 - 28 Feb 2018

Cited by 92 | Viewed by 9870

Abstract

Advances in manufacturing process technology are key ensembles for the production of integrated circuits in the sub-micrometer region. It is of paramount importance to assess the effects of tolerances in the manufacturing process on the performance of modern integrated circuits. The polynomial chaos [...] Read more.

Advances in manufacturing process technology are key ensembles for the production of integrated circuits in the sub-micrometer region. It is of paramount importance to assess the effects of tolerances in the manufacturing process on the performance of modern integrated circuits. The polynomial chaos expansion has emerged as a suitable alternative to standard Monte Carlo-based methods that are accurate, but computationally cumbersome. This paper provides an overview of the most recent developments and challenges in the application of polynomial chaos-based techniques for uncertainty quantification in integrated circuits, with particular focus on high-dimensional problems. Full article

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13 pages, 316 KiB

Open AccessArticle

Maximum Likelihood-Based Methods for Target Velocity Estimation with Distributed MIMO Radar

by Zhenxin Cao, Peng Chen, Zhimin Chen and Xinyi He

Electronics 2018, 7(3), 29; https://doi.org/10.3390/electronics7030029 - 28 Feb 2018

Cited by 4 | Viewed by 4893

Abstract

The estimation problem for target velocity is addressed in this in the scenario with a distributed multi-input multi-out (MIMO) radar system. A maximum likelihood (ML)-based estimation method is derived with the knowledge of target position. Then, in the scenario without the knowledge of [...] Read more.

The estimation problem for target velocity is addressed in this in the scenario with a distributed multi-input multi-out (MIMO) radar system. A maximum likelihood (ML)-based estimation method is derived with the knowledge of target position. Then, in the scenario without the knowledge of target position, an iterative method is proposed to estimate the target velocity by updating the position information iteratively. Moreover, the Carmér-Rao Lower Bounds (CRLBs) for both scenarios are derived, and the performance degradation of velocity estimation without the position information is also expressed. Simulation results show that the proposed estimation methods can approach the CRLBs, and the velocity estimation performance can be further improved by increasing either the number of radar antennas or the information accuracy of the target position. Furthermore, compared with the existing methods, a better estimation performance can be achieved. Full article

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22 pages, 15846 KiB

Open AccessReview

Efficient Fault Localization and Failure Analysis Techniques for Improving IC Yield

by Ankush Oberai and Jiann-Shiun Yuan

Electronics 2018, 7(3), 28; https://doi.org/10.3390/electronics7030028 - 27 Feb 2018

Cited by 12 | Viewed by 13878

Abstract

With the increase in the complexity of the semiconductor device processes and increase in the challenge to satisfy high market demands, enhancement in yield has become a crucial factor. Discovering and reacting to yield problems emerging at the end of the production line [...] Read more.

With the increase in the complexity of the semiconductor device processes and increase in the challenge to satisfy high market demands, enhancement in yield has become a crucial factor. Discovering and reacting to yield problems emerging at the end of the production line may cause unbearable yield loss leading to larger times to market. Thus, time and cost involved in fault isolation may be significantly shortened by effectively utilizing the fault diagnosis technology and supporting yield improvements. Hence for yield analysis, a highly integrated data network with software analysis tools have been established to reduce the fault analysis time. Synopsys Avalon, a product used for fault localization is described in this paper which aids in achieving better integrated circuit yields. This paper also illustrates various fault localization techniques for faster problem identification and discusses a few analytical tools like photon emission microscope and transmission emission microscope for faster determination of device failures. Full article

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10 pages, 5654 KiB

Open AccessArticle

A Tunable Polarization-Dependent Terahertz Metamaterial Absorber Based on Liquid Crystal

by Guangsheng Deng, Yujiao Lu, Zhiping Yin, Weien Lai, Hongbo Lu, Jun Yang, Aifeng Yang, Yang Ye, Dayong Liu and Baihong Chi

Electronics 2018, 7(3), 27; https://doi.org/10.3390/electronics7030027 - 26 Feb 2018

Cited by 11 | Viewed by 5494

Abstract

In this paper, a tunable polarization-dependent terahertz (THz) metamaterial absorber based on liquid crystal (LC) is presented. The measurement results show that absorption peak is at 239.5 GHz for a TE-polarized wave and 306.6 GHz for a TM-polarized wave, without exerting the bias [...] Read more.

In this paper, a tunable polarization-dependent terahertz (THz) metamaterial absorber based on liquid crystal (LC) is presented. The measurement results show that absorption peak is at 239.5 GHz for a TE-polarized wave and 306.6 GHz for a TM-polarized wave, without exerting the bias voltage on the LC layer. An increase in bias voltage affects the orientation of LC molecules and causes redshifted resonant frequencies. By adjusting the bias voltage from 0 to 10 V, frequency tunabilities of 4.7% and 4.1% for TE- and TM-polarized waves, respectively, were experimentally demonstrated. Surface current and power loss distribution was analyzed to explain the physical mechanism of the absorber, while the absorption dependence on geometrical parameters and incident angles was also studied in detail. According to the obtained results, the proposed absorber is shown here to be capable of achieving tunable polarization-dependent absorption, and to have potential application in terahertz polarization imaging, terahertz sensing, and polarization multiplexing. Full article

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Electronics, Volume 7, Issue 3 (March 2018) – 15 articles

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