Circuits

Higher dimensional models of cross-coupled oscillators and application to design

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Ahmed S. Elwakil, et al., "Higher dimensional models of cross-coupled oscillators and application to design." Journal of Circuits, Systems, and Computers 19, (04), 2010, 787. We present four-dimensional and five-dimensional models for classical cross-coupled LC oscillators. Using these models, sinusoidal oscillation condition, frequency and amplitude can be found. Further, undesired behaviors such as relaxation-mode oscillations and latchup can be explained and detected. A simple graphical design procedure is also described.

On-chip antenna: Practical design and characterization considerations

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Atif Shamim, et al., "On-chip antenna: Practical design and characterization considerations." In 2010 14th International Symposium on Antenna Technology and Applied Electromagnetics & the American Electromagnetics Conference, 2010, 1. This paper highlights the challenges of an emergent field, namely, on-chip antenna design. Consistent with the RF System-on-Chip (SoC) concept, co-design strategy for circuits and on-chip antennas is described. A number of design and layout issues, arising from the highly integrated nature of this kind of systems, are discussed. The characterization difficulties

Millimeter-Wave and Terahertz Technologies-Enhanced Plasma Wave Detection of Terahertz Radiation Using Multiple High Electron-Mobility Transistors Connected in Series

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Tamer Elkhatib et al., "Enhanced Plasma Wave Detection of Terahertz Radiation Using Multiple High Electron-Mobility Transistors Connected in Series," in IEEE Transactions on Microwave Theory and Techniques, vol. 58, (2), 2010, 331 We report on enhanced room-temperature detection of terahertz radiation by several connected field-effect transistors. For this enhanced nonresonant detection, we have designed, fabricated, and tested plasmonic structures consisting of multiple InGaAs/GaAs pseudomorphic high electron-mobility transistors connected in series. Results show a 1.63-THz response that is

HP memristor mathematical model for periodic signals and DC

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Ahmed Radwan, et al., " HP memristor mathematical model for periodic signals and DC". In 2010 53rd IEEE International Midwest Symposium on Circuits and Systems, 2010, 861. In this paper mathematical models of the HP Memristor for DC and periodic signal inputs are provided. The need for a rigid model for the Memristor using conventional current and voltage quantities is essential for the development of many promising Memristors' applications. Unlike the previous works, which focuses on the sinusoidal input waveform, we derived rules for any periodic signals in general in terms of voltage and

A best-first tree-searching approach for ML decoding in MIMO system

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Chung-An Shen, et al., "A best-first tree-searching approach for ML decoding in MIMO system." In Proceedings of 2010 IEEE International Symposium on Circuits and Systems, 2010, 3533. In MIMO communication systems maximum-likelihood (ML) decoding can be formulated as a tree-searching problem. This paper presents a tree-searching approach that combines the features of classical depth-first and breadth-first approaches to achieve close to ML performance while minimizing the number of visited nodes. A detailed outline of the algorithm is given, including the required storage. The effects of

Time domain oscillating poles: stability redefined in memristor based Wien-oscillators

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Abdul Hafiz Talukdar, et al., "Time domain oscillating poles: stability redefined in memristor based Wien-oscillators." In 2010 International Conference on Microelectronics, 2010, 288. Traditionally, the necessary and sufficient condition for any system to be oscillating is that its poles are located on the imaginary (jω) axis. In this paper, for the first time, we have shown that systems can oscillate with time-domain oscillating poles. The idea is verified using a Memristor based Wien oscillator. Sustained oscillations are observed without having the poles of the system fixed on the

Nonlinear analysis of ring oscillator circuits

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Xiaoqing Ge, et al., "Nonlinear analysis of ring oscillator circuits." In Proceedings of the 2010 American Control Conference, 2010, 1772. Using nonlinear systems techniques, we analyze the stability properties and synchronization conditions for ring oscillator circuits, which are essential building blocks in digital systems. By making use of its cyclic structure, we investigate local and global stability properties of an n-stage ring oscillator. We present a sufficient condition for global asymptotic stability of the origin and obtain necessity if the ring oscillator consists of identical

An adaptive hybrid multiprocessor technique for bioinformatics sequence alignment

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Talal Bonny, et al., "An adaptive hybrid multiprocessor technique for bioinformatics sequence alignment." In 2010 5th cairo international biomedical engineering conference, 2010, 112. Sequence alignment algorithms such as the Smith-Waterman algorithm are among the most important applications in the development of bioinformatics. Sequence alignment algorithms must process large amounts of data which may take a long time. Here, we introduce our Adaptive Hybrid Multiprocessor technique to accelerate the implementation of the Smith-Waterman algorithm. Our technique utilizes both the graphics

Sinusoidal oscillators with lower gain requirements at higher frequencies based on an explicit tanh(x) nonlinearity

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Ahmed S. Elwakil, et al., "Sinusoidal oscillators with lower gain requirements at higher frequencies based on an explicit tanh (x) nonlinearity." International Journal of Circuit Theory and Applications 38, (7), 2010, 747. Two novel sinusoidal oscillator structures with an explicit tanh(x) nonlinearity are proposed. The oscillators have the attractive feature: the higher the operating frequency, the lower the necessary gain required to start oscillations. A nonlinear model for the two oscillators is derived and verified numerically. Spice simulations using AMS BiCMOS 0.35µ model parameters and

Design, implementation and analysis of fully digital 1-D controllable multiscroll chaos

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Abhinav Mansingka, et al., "Design, implementation and analysis of fully digital 1-D controllable multiscroll chaos" ICM 2011 Proceeding, 2011, 1. This paper introduces the fully digital implementation of a 1-D multiscroll chaos generator based on a staircase nonlinearity in the 3rd-order jerk system using the Euler approximation. For the first time, digital design is exploited to provide real-time controllability of (i) number of scrolls, (ii) position in 1-D space, (iii) Euler step size and (iv) system parameter. The effect of variations in these fields on the maximum Lyapunov exponent (MLE)

Fractional smith chart theory

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Atif Shamim, et al., "Fractional smith chart theory." IEEE Microwave and Wireless Components Letters 21, (3) , 2011, 117. For the first time, a generalized Smith chart is introduced here to represent fractional order circuit elements. It is shown that the standard Smith chart is a special case of the generalized fractional order Smith chart. With illustrations drawn for both the conventional integer based lumped elements and the fractional elements, a graphical technique supported by the analytical method is presented to plot impedances on the fractional Smith chart. The concept is then

Gain-enhanced LTCC system-on-package for automotive UMRR applications

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Farhan Abdul Ghaffar, et al., "Gain-enhanced LTCC system-on-package for automotive UMRR applications." In 2010 53rd IEEE International Midwest Symposium on Circuits and Systems, 2010, 934. Abstract: A novel Low Temperature Co-fired Ceramic (LTCC) based SoP for automotive radar applications is presented. For the first time a combination of a relatively low dielectric constant LTCC substrate and a high dielectric constant LTCC superstrate has been incorporated to enhance the overall gain of the module. The superstrate can provide additional protection to the integrated circuits (IC) in the harsh

On the mathematical modeling of memristors

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Radwan, Ahmed G., et al., "On the mathematical modeling of memristors." In 2010 International Conference on Microelectronics, 2010, 284. Since the fourth fundamental element (Memristor) became a reality by HP labs, and due to its huge potential, its mathematical models became a necessity. In this paper, we provide a simple mathematical model of Memristors characterized by linear dopant drift for sinusoidal input voltage, showing a high matching with the nonlinear SPICE simulations. The frequency response of the Memristor's resistance and its bounding conditions are derived. The fundamentals of

Nonlinear Analysis of Ring Oscillator and Cross-Coupled Oscillator Circuits

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Ge Xiaoqing, et al., "Nonlinear analysis of ring oscillator and cross-coupled oscillator circuits." Dynamics of Continuous, Discrete and Impulsive Systems Series B: Applications and Algorithms , 2010, 1. Hassan Khalil’s research results and beautifully written textbook on nonlinear systems have influenced generations of researchers, including the authors of this paper. Using nonlinear systems techniques, this paper analyzes ring oscillator and cross-coupled oscillator circuits, which are essential building blocks in digital systems. The paper first investigates local and global stability

Evaluation framework for K-Best sphere decoders

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Chung-An Shen, et al., "Evaluation framework for K-best sphere decoders." Journal of Circuits, Systems, and Computers 19 (05), 2010, 975. While Maximum-Likelihood (ML) is the optimum decoding scheme for most communication scenarios, practical implementation difficulties limit its use, especially for Multiple Input Multiple Output (MIMO) systems with a large number of transmit or receive antennas. Tree-searching type decoder structures such as Sphere decoder and K-best decoder present an interesting trade-off between complexity and performance. Many algorithmic developments and VLSI

Enhanced plasma wave detection of terahertz radiation using multiple high electron-mobility transistors connected in series

1 min read ·
Tamer Elkhatib, et al., "Enhanced plasma wave detection of terahertz radiation using multiple high electron-mobility transistors connected in series." IEEE transactions on microwave theory and techniques 58, (2), 2010, 331. We report on enhanced room-temperature detection of terahertz radiation by several connected field-effect transistors. For this enhanced nonresonant detection, we have designed, fabricated, and tested plasmonic structures consisting of multiple InGaAs/GaAs pseudomorphic high electron-mobility transistors connected in series. Results show a 1.63-THz response that is directly

Generalized model for memristor-based Wien family oscillators

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Abdul Hafiz Talukdar, et al., "Generalized model for memristor-based Wien family oscillators." Microelectronics Journal 42 (9), 2011, 1032. In this paper, we report the unconventional characteristics of Memristor in Wien oscillators. Generalized mathematical models are developed to analyze four members of the Wien family using Memristors. Sustained oscillation is reported for all types though oscillating resistance and time dependent poles are present. We have also proposed an analytical model to estimate the desired amplitude of oscillation before the oscillation starts. These Memristor-based

Design and implementation of a sort-free K-best sphere decoder

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Sudip Mondal, et al.,"Design and Implementation of a Sort-Free K-Best Sphere Decoder," in IEEE Transactions on Very Large Scale Integration (VLSI) Systems 18, (10), 2010, 1497. This paper describes the design and very-large-scale integration (VLSI) architecture for a 4 × 4 breadth-first K-best multiple-input-multiple-output (MIMO) decoder using a 64 quadrature-amplitude modulation (QAM) scheme. A novel sort-free approach to path extension, as well as quantized metrics result in a high-throughput VLSI architecture with lower power and area consumption compared to state-of-the-art published

High performance technique for database applications using a hybrid gpu/cpu platform

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Mohamed Zidan, et al., "High performance technique for database applications using a hybrid gpu/cpu platform." In Proceedings of the 21st edition of the great lakes symposium on Great lakes symposium on VLSI, 2011, 85. Many database applications, such as sequence comparing, sequence searching, and sequence matching, etc, process large database sequences. we introduce a novel and efficient technique to improve the performance of database applications by using a Hybrid GPU/CPU platform. In particular, our technique solves the problem of the low efficiency resulting from running short-length

Analysis of bus width and delay on a fully digital signum nonlinearity chaotic oscillator

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Abhinav Mansingka, et al., "Analysis of bus width and delay on a fully digital signum nonlinearity chaotic oscillator." In 2011 IEEE 54th International Midwest Symposium on Circuits and Systems (MWSCAS), 2011, 1. Abstract: This paper introduces the first fully digital implementation of a 3rd order ODE-based chaotic oscillator with signum nonlinearity. A threshold bus width of 12-bits for reliable chaotic behavior is observed, below which the system output becomes periodic. Beyond this threshold, the maximum Lyapunov exponent (MLE) is shown to improve up to a peak value at 16-bits and

Hardware Realization of Chaos Based Block Cipher for Image Encryption

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Mohamed L. Barakat, et al., "Hardware realization of chaos based block cipher for image encryption." In ICM 2011 Proceeding, 2011, 1. Unlike stream ciphers, block ciphers are very essential for parallel processing applications. In this paper, the first hardware realization of chaotic-based block cipher is proposed for image encryption applications. The proposed system is tested for known cryptanalysis attacks and for different block sizes. When implemented on Virtex-IV, system performance showed high throughput and utilized small area. Passing successfully in all tests, our system proved to be

A Compact QPSK Modulator with Low Amplitude and Phase Imbalance for Remote Sensing Applications

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Farhan Abdul Ghaffar, et al., " A Compact QPSK Modulator with Low Amplitude and Phase Imbalance for Remote Sensing Applications" Canadian Journal on Electrical and Electronics Engineering 2, (4), 2011, 1. A new, compact and wide-band Quadrature Phase Shift Keying (QPSK) modulator is presented for remote sensing applications. The microstrip-based modulator employs quadrature hybrid coupler, Wilkinson divider, rat race coupler and GaAs MESFET switches. It is designed to be part of an X band remote sensing transmitter with a center frequency of 8.25GHz. The fabricated module demonstrates the

Random number generation based on digital differential chaos

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Mohamed Zidan, et al., "Random number generation based on digital differential chaos." In 2011 IEEE 54th International Midwest Symposium on Circuits and Systems (MWSCAS), 2011, 1. In this paper, we present a fully digital differential chaos based random number generator. The output of the digital circuit is proved to be chaotic by calculating the output time series maximum Lyapunov exponent. We introduce a new post processing technique to improve the distribution and statistical properties of the generated data. The post-processed output passes the NIST Sp. 800-22 statistical tests. The system

Design and Comparison of LTCC Based Fractal Antennas

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Farhan Abdul Ghaffar, et al., "Design and comparison of LTCC based fractal antennas." In Proc. URSI Gen. Assem. Sci. Symp., 2011, 1. The paper presents design of three different fractal antennas in Low Temperature Co-fired Ceramic (LTCC) substrate. An aperture coupled feeding technique has been used in all the three designs which is highly suitable for multi-layer system on package (SoP) concept. The three fractal designs demonstrated are Sierpinski carpet fractal antenna, Sierpinski gasket fractal antenna and Koch snowflake fractal antenna. Bandwidths of 1.8 GHz (7.5%), 1.75 GHz (7.5%) and 1

High Dynamic Range Adaptive ΑΣ-Based Focal Plane Array Architecture

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Shun Yao, et al., "High Dynamic Range adaptive ΔΣ-based Focal Plane Array architecture." In 2011 Conference Record of the Forty Fifth Asilomar Conference on Signals, Systems and Computers (ASILOMAR), 2011, 505. Abstract: In this paper, an Adaptive Delta-Sigma based architecture for High Dynamic Range (HDR) Focal Plane Arrays is presented. The noise shaping effect of the Delta-Sigma modulation in the low end, and the distortion noise induced in the high end of Photo-diode current were analyzed in detail. The proposed architecture can extend the DR for about 20N log2 dB at the high end of Photo

Theory and Numerical Methods-Fractional Smith Chart Theory

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Atef Shamim, et al., "Fractional Smith Chart Theory," in IEEE Microwave and Wireless Components Letters 21, (3), 117. For the first time, a generalized Smith chart is introduced here to represent fractional order circuit elements. It is shown that the standard Smith chart is a special case of the generalized fractional order Smith chart. With illustrations drawn for both the conventional integer based lumped elements and the fractional elements, a graphical technique supported by the analytical method is presented to plot impedances on the fractional Smith chart. The concept is then applied

FAST GLOBAL SEQUENCE ALIGNMENT TECHNIQUE

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Talal Bonny, et al., "Fast global sequence alignment technique." In 2011 Conference Record of the Forty Fifth Asilomar Conference on Signals, Systems and Computers (ASILOMAR), 2011, 1046. Bioinformatics database is growing exponentially in size. Processing these large amount of data may take hours of time even if super computers are used. One of the most important processing tool in Bioinformatics is sequence alignment. We introduce fast alignment algorithm, called `Alignment By Scanning' (ABS), to provide an approximate alignment of two DNA sequences. We compare our algorithm with the

Memristor-based relaxation oscillators using digital gates

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Moustafa A. Khatib, et al., "Memristor-based relaxation oscillators using digital gates." In 2012 Seventh International Conference on Computer Engineering & Systems (ICCES), 2012, 98. This paper presents two memristor-based relaxation oscillators. The proposed oscillators are designed without the need of any reactive elements, i.e., capacitor or inductor. As the "resistance storage" property of the memristor can be exploited to generate the oscillation. The proposed oscillators have the advantage that they can be fully integrated on-chip giving an area-efficient solution. Furthermore, these

The fractional-order modeling and synchronization of electrically coupled neuron systems

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Khaled Moaddy, et al., "The fractional-order modeling and synchronization of electrically coupled neuron systems" Computers and Mathematics with Applications 64 (10), 2012, 3329. Abstract: In this paper, we generalize the integer-order cable model of the neuron system into the fractional-order domain, where the long memory dependence of the fractional derivative can be a better fit for the neuron response. Furthermore, the chaotic synchronization with a gap junction of two or multi-coupled-neurons of fractional-order are discussed. The circuit model, fractional-order state equations and the

Impedance matching through a single passive fractional element

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Ahmed Radwan, et al., "Impedance matching through a single passive fractional element." In Proceedings of the 2012 IEEE International Symposium on Antennas and Propagation, 2012, 1. For the first time, a generalized admittance Smith chart theory is introduced to represent fractional order circuit elements. The principles of fractional order matching circuits are described. We show that for fractional order α ; 1, a single parallel fractional element can match a wider range of load impedances as compared to its series counterpart. Several matching examples demonstrate the versatility of

Differential RF MEMS interwoven capacitor immune to residual stress warping

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Amro M. Elshurafa, , et al., "Differential RF MEMS interwoven capacitor immune to residual stress warping." Micro & Nano Letters 7 (7), 2012, 658. A RF MEMS capacitor with an interwoven structure is designed, fabricated in the PolyMUMPS process and tested in an effort to address fabrication challenges usually faced in MEMS processes. The interwoven structure was found to offer several advantages over the typical MEMS parallel-plate design including eliminating the warping caused by residual stress, eliminating the need for etching holes, suppressing stiction, reducing parasitics and providing

Fractional-order RC and RL circuits

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Ahmed Radwan, et al., "Fractional-order RC and RL circuits" Circuits, Systems, and Signal Processing 31 (6), 2012, 1901. This paper is a step forward to generalize the fundamentals of the conventional RC and RL circuits in fractional-order sense. The effect of fractional orders is the key factor for extra freedom, more flexibility, and novelty. The conditions for RC and RL circuits to act as pure imaginary impedances are derived, which are unrealizable in the conventional case. In addition, the sensitivity analyses of the magnitude and phase response with respect to all parameters showing the

The integrated satellite-acoustic telemetry (iSAT) system for tracking marine megafauna

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De la Torre Pedro, et al., "The integrated satellite-acoustic telemetry (iSAT) system for tracking marine megafauna." In 2012 Oceans-Yeosu, 2012, 1. This document describes the integrated satellite-acoustic telemetry (iSAT) system: an autonomous modular system for tracking the movements of large pelagic fish using acoustic telemetry and satellite communications. The sensor platform is described along with the propulsion and navigation systems. An application for tracking the whale shark (Rhincodon typus) in the Red Sea is included along with a discussion of the technical difficulties that such

Memristor-based mono-stable oscillator

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Bahgat, A. T., et al., "Memristor-based mono-stable oscillator." arXiv preprint , (2012). In this letter, a reactance-less mono-stable oscillator is introduced for the first time using memristors. By replacing bulky inductors and capacitors with memristors, the novel mono-stable oscillator can be an area-efficient solution for on-chip fully integrated systems. The proposed circuit is described, mathematically analysed and verified by circuit simulations.

Memristor: the illusive device

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Salama, Khaled Nabil. et al., "Memristor: the illusive device." In Proceedings of the great lakes symposium on VLSI, 2012, 208. The memristor (M) is considered to be the fourth two-terminal passive element in electronics, alongside the resistor (R), the capacitor (C), and the inductor (L). Its existence was postulated in 1971 but its first implementation was reported in 2008. Where was it hiding all that time and what can we do with it? Come and learn how the memristor completes the roster of electronic devices much like a missing particle that physicists seek to complete their tableaus.

Two-layer radio frequency MEMS fractal capacitors in PolyMUMPS for S-band applications

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Amro Elshurafa, et al., "Two-layer radio frequency MEMS fractal capacitors in PolyMUMPS for S-band applications." Micro & Nano Letters 7, (5), 2012, 419. In this Letter, the authors fabricate for the first time MEMS fractal capacitors possessing two layers and compare their performance characteristics with the conventional parallel-plate capacitor and previously reported state-of-the-art single-layer MEMS fractal capacitors. Explicitly, a capacitor with a woven structure and another with an interleaved configuration were fabricated in the standard PolyMUMPS surface micromachining process and

Low-voltage puzzle-like fractal microelectromechanial system variable capacitor suppressing pull-in

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Amro M. Elshurafa, et al., "Low-voltage puzzle-like fractal microelectromechanial system variable capacitor suppressing pull-in" Micro & Nano Letters 7, (9), 2012, 965. Abstract: This Letter introduces an electrostatically actuated fractal MEMS variable capacitor that, by utilising the substrate, extends the tuning range (TR) beyond the theoretical limit of 1.5 as dictated by the pull-in phenomenon. The backbone concept behind the fractal varactor is to create a suspended movable plate possessing a specific fractal geometry, and to simultaneously create a bottom fixed plate complementary in

Two-layer radio

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Amro Elshurafa, et al., "Two-layer radio frequency MEMS fractal capacitors in PolyMUMPS for S-band applications." Micro & Nano Letters 7 (5), 2012, 419. In this letter, we fabricate for the first time MEMS fractal capacitors possessing two layers and compare their performance characteristics with the conventional parallel-plate capacitor and previously reported state-of-the-art singlelayer MEMS fractal capacitors. Explicitly, a capacitor with a woven structure and another with an interleaved configuration were fabricated in the standard PolyMUMPS surface micromachining process and tested at S

Determination of maximum power transfer conditions of bimorph piezoelectric energy harvesters

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Mahmoud Al Ahmad, et al., "Determination of maximum power transfer conditions of bimorph piezoelectric energy harvesters." Journal of Applied Physics 111 (10), 2012, 102812 In this paper, a method to find the maximum power transfer conditions in bimorph piezoelectric-based harvesters is proposed. Explicitly, we derive a closed form expression that relates the load resistance to the mechanical parameters describing the bimorph based on the electromechanical, single degree of freedom, analogy. Further, by taking into account the intrinsic capacitance of the piezoelectric harvester, a more

Effect of boundary on controlled memristor-based oscillator

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Mohamed E. Fouda, et al., "Effect of boundary on controlled memristor-based oscillator." In 2012 International Conference on Engineering and Technology (ICET), 2012, 1. Abstract: Recently, the applications of memristors have spread into many fields and especially in the circuit theory. Many models have been proposed for the HP-memristor based on the window functions. In this paper, we introduce a complete mathematical analysis of the controlled reactance-less oscillator for two different window functions of Joglekar's model (linear and nonlinear dopant drift) to discuss the effect of changing

Fully Digital 1-D, 2-D and 3-D Multiscroll Chaos as Hardware Pseudo Random Number Generators

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Abhinav Mansingka, et al., "Fully digital 1-D, 2-D and 3-D multiscroll chaos as hardware pseudo random number generators." In 2012 IEEE 55th International Midwest Symposium on Circuits and Systems (MWSCAS), 2012, 1180. This paper introduces the first fully digital implementation of 1-D, 2-D and 3-D multiscroll chaos using the sawtooth nonlinearity in a 3rd order ODE with the Euler approximation. Systems indicate chaotic behaviour through phase space boundedness and positive Lyapunov exponent. Low-significance bits form a PRNG and pass all tests in the NIST SP. 800-22 suite without post

Non linear dynamics of memristor based 3rd order oscillatory system

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Arka Talukdar, et al., "Non linear dynamics of memristor based 3rd order oscillatory system." Microelectronics journal 43 (3), 2012, 169. In this paper, we report for the first time the nonlinear dynamics of three memristor based phase shift oscillators, and consider them as a plausible solution for the realization of parametric oscillation as an autonomous linear time variant system. Sustained oscillation is reported through oscillating resistance while time dependent poles are present. The memristor based phase shift oscillator is explored further by varying the parameters so as to present

A Best-First Soft/Hard Decision Tree Searching MIMO Decoder for a 4×4 64-QAM System

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Chung-An Shen, et al., "A Best-First Soft/Hard Decision Tree Searching MIMO Decoder for a 4×4 64-QAM System" IEEE Transactions on Very Large Scale Integration (VLSI) Systems 20, (8), 2012, 1537. Abstract: This paper presents the algorithm and VLSI architecture of a configurable tree-searching approach that combines the features of classical depth-first and breadth-first methods. Based on this approach, techniques to reduce complexity while providing both hard and soft outputs decoding are presented. Furthermore, a single programmable parameter allows the user to tradeoff throughput versus BER

Microscale Electrostatic Fractional Capacitors using Reduced Graphene Oxide Percolated Polymer Composites

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Amro M Elshurafa, et al., "Microscale Electrostatic Fractional Capacitors using Reduced Graphene Oxide Percolated Polymer Composites" Applied Physics Letters 102, 2013, 232991. Abstract: We show that graphene-percolated polymer composites exhibit fractional capacitance response in the frequency range of 50 kHz–2 MHz. In addition, it is shown that by varying the loading of graphene within the matrix from 2.5% to 12%, the phase can be controllably tuned from −67° to −31°, respectively. The electrostatic fractional capacitors proposed herein are easy to fabricate and offer integration capability

On the short-term predictability of fully digital chaotic oscillators for pseudo-random number generation

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Ahmed G. Radwan, et al., "On the short-term predictability of fully digital chaotic oscillators for pseudo-random number generation." In 2013 IEEE 20th International Conference on Electronics, Circuits, and Systems (ICECS), 2013, 373. This paper presents a digital implementation of a 3rd order chaotic system using the Euler approximation. Short-term predictability is studied in relation to system precision, Euler step size and attractor size and optimal parameters for maximum performance are derived. Defective bits from the native chaotic output are neglected and the remaining pass the NIST SP

Secure Ds-CDMA spreading codes using fully digital multidimensional multiscroll chaos

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Abhinav S. Mansingka, et al., "Secure Ds-CDMA spreading codes using fully digital multidimensional multiscroll chaos." In 2013 IEEE 56th International Midwest Symposium on Circuits and Systems (MWSCAS), 2013, 1334. This paper introduces a generalized fully digital hardware implementation of 1-D, 2-D and 3-D multiscroll chaos through sawtooth nonlinearities in a 3rd order ODE with the Euler approximation, wherein low-significance bits pass all NIST SP. 800-22 tests. The low-significance bits show good performance as spreading code for multiple-access DS-CDMA in AWGN and multipath environments

Fibonacci-based hardware post-processing for non-autonomous signum hyperchaotic system

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bhinav AMansingka, et al., "Fibonacci-based hardware post-processing for non-autonomous signum hyperchaotic system." In 2013 International Conference on IT Convergence and Security (ICITCS), 2013, 1. This paper presents a hardware implementation of a robust non-autonomous hyperchaotic-based PRNG driven by a 256-bit LFSR. The original chaotic output is post-processed using a novel technique based on the Fibonacci series, bitwise XOR, rotation, and feedback. The proposed post-processing technique preserves the throughput of the system and enhances the randomness in the output which is verified

Implantable intraocular pressure monitoring systems: Design considerations

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Muhammad Arsalan, et al., "Implantable intraocular pressure monitoring systems: Design considerations." In 2013 IEEE MTT-S International Microwave Workshop Series on RF and Wireless Technologies for Biomedical and Healthcare Applications (IMWS-BIO), 2013, 1. Design considerations and limitations of implantable Intraocular Pressure Monitoring (IOPM) systems are presented in this paper. Detailed comparison with the state of the art is performed to highlight the benefits and challenges of the proposed design. The system-on-chip, presented here, is battery free and harvests energy from incoming RF

ISAT: The mega-fauna acoustic tracking system

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De la Torre Pedro, et al., "ISAT: The mega-fauna acoustic tracking system." In 2013 MTS/IEEE OCEANS-Bergen, 2013, 1. The acoustic tracking module of the Integrated Satellite and Acoustic Telemetry (iSAT) system is discussed in detail. iSAT is capable of detecting the relative direction of an acoustic source by measuring the order of arrival (OOA) of the acoustic signal to each hydrophone in a triangular array. The characteristics of the hydrophones, the projector, and the target acoustic signal used for iSAT are described. Initially it is designed to study the movements of whale sharks

Parametric control on fractional-order response for Lü chaotic system

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Khaled Moaddy, et al., "Parametric control on fractional-order response for Lü chaotic system." In Journal of Physics: Conference Series, 423, (1), 2013, 012024. Abstract. This paper discusses the influence of the fractional order parameter on conventional chaotic systems. These fractional-order parameters increase the system degree of freedom allowing it to enter new domains and thus it can be used as a control for such dynamical systems. This paper investigates the behaviour of the equally-fractional-order Lü chaotic system when changing the fractional-order parameter and determines the

Modeling and fabrication of an RF MEMS variable capacitor with a fractal geometry

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Elshurafa, A. M., et al., "Modeling and fabrication of an RF MEMS variable capacitor with a fractal geometry". In 2013 IEEE International Symposium on Circuits and Systems, 2013, 2711. In this paper, we model, fabricate, and measure an electrostatically actuated MEMS variable capacitor that utilizes a fractal geometry and serpentine-like suspension arms. Explicitly, a variable capacitor that possesses a top suspended plate with a specific fractal geometry and also possesses a bottom fixed plate complementary in shape to the top plate has been fabricated in the PolyMUMPS process. An important

Generalized Hardware Post Processing Technique for Chaos-Based Pseudorandom Number Generators

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Mohamed L. Barakat, et al., "Generalized Hardware Post Processing Technique for Chaos-Based Pseudorandom Number Generators" ETRI Journal, 35, (3), 2013, 448. Abstract: This paper presents a generalized post‐processing technique for enhancing the pseudorandomness of digital chaotic oscillators through a nonlinear XOR‐based operation with rotation and feedback. The technique allows full utilization of the chaotic output as pseudorandom number generators and improves throughput without a significant area penalty. Digital design of a third‐order chaotic system with maximum function nonlinearity is

Improved Memristor-Based Relaxation Oscillator

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Ahmed G. Musad, et al., "Improved Memristor-Based Relaxation Oscillator" Microelectronics Journal Volume 44, (9), 2013, 814. Abstract: This paper presents an improved memristor-based relaxation oscillator which offers higher frequency and wider tunning range than the existing reactance-less oscillators. It also has the capability of operating on two positive supplies or alternatively a positive and negative supply. Furthermore, it has the advantage that it can be fully integrated on-chip providing an area-efficient solution. On the other hand, The oscillation concept is discussed then a

Fully digital jerk-based chaotic oscillators for high throughput pseudo-random number generators up to 8.77 Gbitss

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Abhinav S. Mansingka, et al., "Fully digital jerk-based chaotic oscillators for high throughput pseudo-random number generators up to 8.77 Gbitss" Microelectronics Journal 44, (9), 2013, 744. Abstract: This paper introduces fully digital implementations of four different systems in the 3rd order jerk-equation based chaotic family using the Euler approximation. The digitization approach enables controllable chaotic systems that reliably provide sinusoidal or chaotic output based on a selection input. New systems are introduced, derived using logical and arithmetic operations between two system

Memristor-based memory The sneak paths problem and solutions

1 min read ·
Mohammed A. Zidan, et al., "Memristor-based memory The sneak paths problem and solutions" Microelectronics Journal 44, (2), 2013, 176. Abstract: In this paper, we investigate the read operation of memristor-based memories. We analyze the sneak paths problem and provide a noise margin metric to compare the various solutions proposed in the literature. We also analyze the power consumption associated with these solutions. Moreover, we study the effect of the aspect ratio of the memory array on the sneak paths. Finally, we introduce a new technique for solving the sneak paths problem by gating

5.2-GHz RF Power Harvesting Module in 0.18 μm CMOS for Biomedical Implantable Sensors

1 min read ·
Mahmoud H. Ouda, et al., "5.2-GHz RF Power Harvesting Module in 0.18 μm CMOS for Biomedical Implantable Sensors" IEEE Transactions on Microwave Theory and Techniques 61, (5), 2013, 2177. Abstract: A first fully integrated 5.2-GHz CMOS-based RF power harvester with an on-chip antenna is presented in this paper. The design is optimized for sensors implanted inside the eye to wirelessly monitor the intraocular pressure of glaucoma patients. It includes a five-stage RF rectifier with an on-chip antenna, a dc voltage limiter, two voltage sensors, a low dropout voltage regulator, and MOSCAP based on

50V All-PMOS Charge Pumps Using Low-Voltage Capacitors

1 min read ·
Ahmed Emira, et al., "50V All-PMOS Charge Pumps Using Low-Voltage Capacitors" IEEE Transactions on Industrial Electronics 60, (10), 2013, 4683. Abstract: In this paper, two high-voltage charge pumps (CPs) are introduced. In order to minimize the area of the pumping capacitors, which dominates the overall area of the CP, high-density capacitors have been utilized. Nonetheless, these high-density capacitors suffer from low breakdown voltage, which is not compatible with the targeted high-voltage application. To circumvent the breakdown limitation, a special clocking scheme is used to limit the

Towards neuromorphic electronics: Memristors on foldable silicon fabric

1 min read ·
MT Ghoneim, et al., "Towards neuromorphic electronics: Memristors on foldable silicon fabric" Microelectronics Journal 45 (11), 2014, 1392. The advantages associated with neuromorphic computation are rich areas of complex research. We address the fabrication challenge of building neuromorphic devices on structurally foldable platform with high integration density. We present a CMOS compatible fabrication process to demonstrate for the first time memristive devices fabricated on bulk monocrystalline silicon (100) which is next transformed into a flexible thin sheet of silicon fabric with all

An integrated energy-efficient capacitive sensor digital interface circuit

1 min read ·
Hesham Omran, et al., "An integrated energy-efficient capacitive sensor digital interface circuit." Sensors and Actuators A: Physical 216, 2014, 43. In this paper, we propose an energy-efficient 13-bit capacitive sensor interface circuit. The proposed design fully relies on successive approximation algorithm, which eliminates the need for oversampling and digital decimation filtering, and thus low-power consumption is achieved. The proposed architecture employs a charge amplifier stage to achieve parasitic insensitive operation and fine absolute resolution. Moreover, the output code is not

Control and switching synchronization of fractional order chaotic systems using active control technique

1 min read ·
Ahmed G. Radwan, et al., "Control and switching synchronization of fractional order chaotic systems using active control technique." Journal of Advanced Research 5 (1), 2014, 125. This paper discusses the continuous effect of the fractional order parameter of the Lü system where the system response starts stable, passing by chaotic behavior then reaching periodic response as the fractional-order increases. In addition, this paper presents the concept of synchronization of different fractional order chaotic systems using active control technique. Four different synchronization cases are

Memristor Multi-Port Readout: A Closed-Form Solution for Sneak-Paths

1 min read ·
Mohamed Zidan, et al., "Memristor multiport readout: A closed-form solution for sneak paths." IEEE Transactions on Nanotechnology 13 (20), 2014, 274. In this paper, we introduce for the first time, a closed-form solution for the memristor-based memory sneak paths without using any gating elements. The introduced technique fully eliminates the effect of sneak paths by reading the stored data using multiple access points and evaluating a simple addition/subtraction on the different readings. The new method requires fewer reading steps compared to previously reported techniques, and has a very

A family of memristor‐based reactance‐less oscillators

1 min read ·
mohamed Zidan, et al., "A family of memristor‐based reactance‐less oscillators." International Journal of Circuit Theory and Applications 42 (11), 2014, 1103. In this paper, we present for the first time a family of memristor‐based reactance‐less oscillators (MRLOs). The proposed oscillators require no reactive components, that is, inductors or capacitors, rather, the ‘resistance storage’ property of memristor is exploited to generate the oscillation. Different types of MRLO family are presented, and for each type, closed form expressions are derived for the oscillation condition, oscillation

A 7.9 pJ/Step Energy-Efficient Multi-Slope 13-bit Capacitance-to-Digital Converter

1 min read ·
Hesham Omran, et al., "7.9 pJ/step energy-efficient multi-slope 13-bit capacitance-to-digital converter." IEEE Transactions on Circuits and Systems II: Express Briefs 61 (8), 2014, 589. In this brief, an energy-efficient capacitance-to-digital converter (CDC) is presented. The proposed CDC uses digitally controlled coarse-fine multi-slope integration to digitize a wide range of capacitance in short conversion time. Both integration current and frequency are scaled, which leads to significant improvement in the energy efficiency of both analog and digital circuitry. Mathematical analysis for

Ultrafast nonlinear response of gold gyroid three-dimensional metamaterials

1 min read ·
Petros Farah, et al., "Ultrafast nonlinear response of gold gyroid three-dimensional metamaterials." Physical Review Applied 2, (4), 2014, 044002. We explore the nonlinear optical response of three-dimensional gyroidal metamaterials, which show greater than tenfold enhancements compared to all other metallic nanomaterials as well as bulk gold. A simple analytical model for this metamaterial response shows how the reflectivity spectrum scales with the metal fill fraction and the refractive index of the material that the metallic nanostructure is embedded in. The ultrafast response arising from

Interference mitigation for broadcast in hierarchical cell structure networks: Transmission strategy and area spectral efficiency

1 min read ·
Yuli Yang, et al., "Interference mitigation for broadcast in hierarchical cell structure networks: Transmission strategy and area spectral efficiency." IEEE Transactions on Vehicular Technology 63 (8), 2014, 3818. Abstract: In this paper, a hierarchical cell structure (HCS) is considered, where an access point (AP) broadcasts to local nodes (LNs) over orthogonal frequency subbands within a local cell located in a macrocell. Since the local cell shares the spectrum licensed to the macrocell, a given LN is interfered with by the macrocell user (MU)'s transmissions over the same subband. To

Achieving nanoscale horizontal separations in the standard 2 μm PolyMUMPS process

1 min read ·
Amro M Elshurafa, et al., "Achieving nanoscale horizontal separations in the standard 2 μm PolyMUMPS process." Applied Nanoscience 4 (2), 2014, 241. This paper shares with the research community how to achieve, effectively and easily, lateral submicron separations in the standard 2 μm PolyMUMPS process without any fabrication intervention or post-processing, based on the oxide sidewall spacer technique. Thousands of nanoseparations were created and successfully tested by visual inspection and by a simple capacitance measurement. The lateral separations attained were less than 440 nm and

Hardware stream cipher with controllable chaos generator for colour image encryption

1 min read ·
Mohamed L. Barakat, et al., "Hardware stream cipher with controllable chaos generator for colour image encryption" IET Image Processing 8 (1), 2014, 33. This study presents hardware realisation of chaos-based stream cipher utilised for image encryption applications. A third-order chaotic system with signum non-linearity is implemented and a new post processing technique is proposed to eliminate the bias from the original chaotic sequence. The proposed stream cipher utilises the processed chaotic output to mask and diffuse input pixels through several stages of XORing and bit permutations. The

Compensated readout for high-density MOS-gated memristor crossbar array

1 min read ·
Mohamed Zidan, et al., "Compensated readout for high-density MOS-gated memristor crossbar array." IEEE Transactions on Nanotechnology 14 (1), 2014, 3. Leakage current is one of the main challenges facing high-density MOS-gated memristor arrays. In this study, we show that leakage current ruins the memory readout process for high-density arrays, and analyze the tradeoff between the array density and its power consumption. We propose a novel readout technique and its underlying circuitry, which is able to compensate for the transistor leakage-current effect in the high-density gated memristor

Insights on capacitive interdigitated electrodes coated with MOF thin films: Humidity and VOCs sensing as a case study

1 min read ·
Christos Sapsanis, et al., "Insights on capacitive interdigitated electrodes coated with MOF thin films: Humidity and VOCs sensing as a case study." Sensors 15 (8), 2015, 18153. A prototypical metal-organic framework (MOF), a 2D periodic porous structure based on the assembly of copper ions and benzene dicarboxylate (bdc) ligands (Cu (bdc)· xH 2 O), was grown successfully as a thin film on interdigitated electrodes (IDEs). IDEs have been used for achieving planar CMOS-compatible low-cost capacitive sensing structures for the detection of humidity and volatile organic compounds (VOCs)

Memristors Empower Spiking Neurons With Stochasticity

1 min read ·
Maruan Al-Shedivat, et al., "Memristors empower spiking neurons with stochasticity." IEEE journal on Emerging and Selected Topics in Circuits and Systems 5 (2), 2015, 242. Abstract: Recent theoretical studies have shown that probabilistic spiking can be interpreted as learning and inference in cortical microcircuits. This interpretation creates new opportunities for building neuromorphic systems driven by probabilistic learning algorithms. However, such systems must have two crucial features: 1) the neurons should follow a specific behavioral model, and 2) stochastic spiking should be

Spectrum band selection in delay-QoS constrained cognitive radio networks

1 min read ·
Yuli Yang, et al., "Spectrum band selection in delay-QoS constrained cognitive radio networks." IEEE Transactions on Vehicular Technology 64 (7), 2014, 2925. Abstract: In this paper, a cognitive radio (CR) network with multiple spectrum bands available for secondary users (SUs) is considered. For the SU's active spectrum-band selection, two criteria are developed. One is to select the band with the highest secondary channel power gain, and the other is to select the band with the lowest interference channel power gain to primary users (PUs). With the quality-of-service (QoS) requirement

A low‐power 802.11 ad compatible 60‐GHz phase‐locked loop in 65‐nm CMOS

1 min read ·
Hammad M. Cheema, et al., "A low‐power 802.11 ad compatible 60‐GHz phase‐locked loop in 65‐nm CMOS" Microwave and Optical Technology Letters 57 (3), 2015, 660. A 60‐GHz fundamental frequency phase locked loop (PLL) as part of a highly integrated system‐on‐chip transmitter with on‐chip memory and antenna is presented. As a result of localized optimization approach for each component, the PLL core components only consume 30.2 mW from a 1.2 V supply. A systematic design procedure to achieve high phase margin and wide locking range is presented. The reduction of parasitic and fixed capacitance

Wavy Channel TFT-Based Digital Circuits

1 min read ·
Amir N. Hanna, et al., "Wavy Channel TFT-Based Digital Circuits." IEEE Transactions on Electron Devices 63 (4), 2016, 1550. Abstract: We report a wavy channel (WC) architecture thin-film transistor-based digital circuitry using ZnO as a channel material. The novel architecture allows for extending device width by integrating vertical finlike substrate corrugations giving rise to 50% larger device width, without occupying extra chip area. The enhancement in the output drive current is 100%, when compared with conventional planar architecture for devices occupying the same chip area. The current

Statistical Analysis for Memristor Crossbar Memories

1 min read ·
Rawan Naous, et al., "Statistical Analysis for Memristor Crossbar Memories." Int. Journal of Unconventional Computing 12, 2016, 251. The inherent memory capabilities bound with compactness and scalability features pose the memristor as an ideal rival for conventional nonvolatile memories. Its use within a crossbar structure offers high-density storage and tight dimensionality. A fitting parameter in the midst of the trend towards nanoscale integration, where gateless memories are on the rise in an attempt to achieve further space savings. Nonetheless, the gate sacrifice comes at the expense of

Experimental Verification of on Chip CMOS Fractional-Order Capacitor Emulators

1 min read ·
Georgia Tsirimokou, et al., "Experimental verification of on-chip CMOS fractional-order capacitor emulators." Electronics Letters 52 (15) , 2016, 1298. The experimental results from a fabricated integrated circuit of fractional-order capacitor emulators are reported. The chip contains emulators of capacitors of orders 0.3, 0.4, 0.5, 0.6 and 0.7 with nano-Farad pseudo-capacitances that can be adjusted through a bias current. Two off-chip capacitors are used to set the bandwidth of each emulator independently. The chip was designed in Austria microsystems (AMS) 0.35μ CMOS.

Cloaking through cancellation of diffusive wave scattering

1 min read ·
Mohamed Farhat, et al., "Cloaking through cancellation of diffusive wave scattering." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 472, 2016, 20160276. A new cloaking mechanism, which makes enclosed objects invisible to diffusive photon density waves, is proposed. First, diffusive scattering from a basic core–shell geometry, which represents the cloaked structure, is studied. The conditions of scattering cancellation in a quasi-static scattering regime are derived. These allow for tailoring the diffusivity constant of the shell enclosing the object so

Memristor-based neural networks: Synaptic versus neuronal stochasticity

1 min read ·
Rawan Naous, et al., "Memristor-based neural networks: Synaptic versus neuronal stochasticity." Aip Advances 6, (11), 2016, 111304. In neuromorphic circuits, stochasticity in the cortex can be mapped into the synaptic or neuronal components. The hardware emulation of these stochastic neural networks are currently being extensively studied using resistive memories or memristors. The ionic process involved in the underlying switching behavior of the memristive elements is considered as the main source of stochasticity of its operation. Building on its inherent variability, the memristor is

A light responsive two-component supramolecular hydrogel: a sensitive platform for the fabrication of humidity sensors

1 min read ·
Suman Samai, et al., "A light responsive two-component supramolecular hydrogel: a sensitive platform for the fabrication of humidity sensors." Soft matter 12 (11), 2016, 2842. The supramolecular assembly of anionic azobenzene dicarboxylate and cationic cetyltrimethylammonium bromide (CTAB) formed a stimuli responsive hydrogel with a critical gelation concentration (CGC) of 0.33 wt%. This self-sustainable two-component system was able to repair damage upon light irradiation. Moreover, it was successfully employed in the fabrication of highly sensitive humidity sensors for the first time.

Compatibility analysis of 3D printer resin for biological applications

1 min read ·
Shilpa Siyashankar, et al., "Compatibility analysis of 3D printer resin for biological applications" Micro & Nano Letters, 11 (10), 2016, 654. The salient features of microfluidics such as reduced cost, handling small sample and reagent volumes and less time required to fabricate the devices has inspired the present work. The incompatibility of three-dimensional printer resins in their native form and the method to improve their compatibility to many biological processes via surface modification are reported. The compatibility of the material to build microfluidic devices was evaluated in

Flash μ-fluidics: a rapid prototyping method for fabricating microfluidic devices

1 min read ·
Ulrich Buttner, et al., "Flash μ-fluidics: a rapid prototyping method for fabricating microfluidic devices." Rsc Advances 6 (78), 2016, 74822. Microfluidics has advanced in terms of design and structures; however, fabrication methods are time-consuming or expensive relative to facility costs and equipment needed. This work demonstrates a fast and economically viable 2D/3D maskless digital light-projection method based on a stereolithography process. Unlike other fabrication methods, one exposure step is used to form the whole device. Flash microfluidics is achieved by incorporating bonding and

Pilot assisted readout for passive memristor crossbars

1 min read ·
Rawan Naous, et al., "Pilot assisted readout for passive memristor crossbars." Microelectronics Journal 54, 2016 48. The high demands for performance and energy efficiency pose significant challenges for computational systems. Memristor-based crossbar architectures are actively considered as vital rivals for the traditional solutions. Nonetheless, density and energy driven passive array structures, that lack a switching control per cell, suffer from sneak paths that limit the range of accurate operation of the crossbar array. In this paper, the crossbar array is treated as a communication

Matching properties of femtofarad and sub-femtofarad MOM capacitors

1 min read ·
Hesham Omran, et al., "Matching properties of femtofarad and sub-femtofarad MOM capacitors." IEEE Transactions on Circuits and Systems I 63 (6) ,2016, 763. Small metal-oxide-metal (MOM) capacitors are essential to energy-efficient mixed-signal integrated circuit design. However, only few reports discuss their matching properties based on large sets of measured data. In this paper, we report matching properties of femtofarad and sub-femtofarad MOM vertical-field parallel-plate capacitors and lateral-field fringing capacitors. We study the effect of both the finger-length and finger-spacing on

Direct mismatch characterization of femtofarad capacitors

1 min read ·
Hesham Omran, et al., "Direct mismatch characterization of femtofarad capacitors" IEEE Transactions on Circuits and Systems II: Express Briefs 63 (2), 2016, 151. Abstract: Reducing the capacitance of programmable capacitor arrays (PCAs), commonly used in analog integrated circuits, is necessary for low-energy applications. However, limited mismatch data are available for small capacitors. We report mismatch measurement for a 2-fF poly-insulator-poly (PIP) capacitor, which is the smallest reported PIP capacitor to the best of the authors' knowledge. Instead of using complicated custom on-chip

Wide-range adaptive RF-to-DC power converter for UHF RFIDs

1 min read ·
Mahmoud H. Ouda, et al., "Wide-range adaptive RF-to-DC power converter for UHF RFIDs." IEEE Microwave and Wireless Components Letters 26 (8), 2016, 634. A wide-range, differential, cross-coupled rectifier is proposed with an extended dynamic range of input RF power that enables wireless powering from varying distances. The proposed architecture mitigates the reverse-leakage problem in conventional, cross-coupled rectifiers without degrading sensitivity. A prototype is designed for UHF RFID applications, and is implemented using 0.18 μm CMOS technology. On-chip measurements demonstrate a

Single-readout high-density memristor crossbar

1 min read ·
Mohammed A. Zidan, et al., "Single-readout high-density memristor crossbar." Scientific reports 6, 2016, 18863. High-density memristor-crossbar architecture is a very promising technology for future computing systems. The simplicity of the gateless-crossbar structure is both its principal advantage and the source of undesired sneak-paths of current. This parasitic current could consume an enormous amount of energy and ruin the readout process. We introduce new adaptive-threshold readout techniques that utilize the locality and hierarchy properties of the computer-memory system to address the

Stochasticity Modeling in Memristors

1 min read ·
Rawan Naous, et al., "Stochasticity modeling in memristors." IEEE Transactions on Nanotechnology 15 (1), 2016, 15. Abstract: Diverse models have been proposed over the past years to explain the exhibiting behavior of memristors, the fourth fundamental circuit element. The models varied in complexity ranging from a description of physical mechanisms to a more generalized mathematical modeling. Nonetheless, stochasticity, a widespread observed phenomenon, has been immensely overlooked from the modeling perspective. This inherent variability within the operation of the memristor is a vital

Zinc Oxide Integrated Wavy Channel Thin-Film Transistor-Based High-Performance Digital Circuits

1 min read ·
Amir N. Hanna, , et al., "Zinc oxide integrated wavy channel thin-film transistor-based high-performance digital circuits." IEEE Electron Device Letters 37 (2), 2016, 193. Abstract: High-performance thin film transistor (TFT) can be a great driving force for display, sensor/actuator, integrated electronics, and distributed computation for the Internet of Everything applications. While semiconducting oxides, such as zinc oxide (ZnO), present promising opportunity in that regard, still wide area of improvement exists to increase the performance further. Here, we show a wavy channel (WC)

Integration of fractal biosensor in a digital microfluidic platform

1 min read ·
Yousof Mashraei, et al., "Integration of fractal biosensor in a digital microfluidic platform." IEEE Sensors Journal 16 (24), 2016, 8775. Abstract: The digital microfluidic (DMF) platform introduces many applications in biomedical assays. If it is to be commercially available to the public, it needs to have the essential features of smart sensing and a compact size. In this paper, we report on a fractal electrode biosensor that is used for both droplet actuation and sensing C-reactive protein (CRP) concentration levels to assess cardiac disease risk. Our proposed electrode is the first two

Ferroelectric Fractional‐Order Capacitors

1 min read ·
Agamaryat Agambayev, et al., " Ferroelectric Fractional‐Order Capacitors". ChemElectroChem, 4(11), 2017, 2807. Poly(vinylidene fluoride)‐based polymers and their blends are used to fabricate electrostatic fractional‐order capacitors. This simple but effective method allows us to precisely tune the constant phase angle of the resulting fractional‐order capacitor by changing the blend composition. Additionally, we have derived an empirical relationship between the ratio of the blend constituents and the constant phase angle to facilitate the design of a fractional‐order capacitor with a desired

3D‐Printed Disposable Wireless Sensors with Integrated Microelectronics for Large Area Environmental Monitoring

1 min read ·
muhamad F. Farooqui, et al., "3D‐Printed Disposable Wireless Sensors with Integrated Microelectronics for Large Area Environmental Monitoring". Advanced Materials Technologies, 2(8), 2017, 1700051. Large area environmental monitoring can play a crucial role in dealing with crisis situations. However, it is challenging as implementing a fixed sensor network infrastructure over large remote area is economically unfeasible. This work proposes disposable, compact, dispersible 3D‐printed wireless sensor nodes with integrated microelectronics which can be dispersed in the environment and work in

Performance analysis of fractional-order PID controller for a parabolic distributed solar collector

1 min read ·
Shahrazad Elmetennani, et al., " Performance analysis of fractional-order PID controller for a parabolic distributed solar collector". In 2017 IEEE AFRICON, 2017, 440. Abstract: This paper studies the performance of a fractional-order proportional integral derivative (FOPID) controller designed for parabolic distributed solar collectors. The control problem addressed in concentrated solar collectors aims at forcing the produced heat to follow a desired reference despite the unevenly varying solar irradiance. In addition to the unpredictable variations of the energy source, the parabolic solar

Experimental behavior evaluation of series and parallel connected constant phase elements

1 min read ·
Georgia Tsirimokou, et al., "Experimental behavior evaluation of series and parallel connected constant phase elements". AEU-International Journal of Electronics and Communications, 74, 2017, 5. Fractional-order capacitors are the core building blocks for implementing fractional-order circuits. Due to the absence of their commercial availability, they can be approximated through appropriately configured passive or active integer-order element topologies. Such a topology, constructed using Operational Transconductance Amplifiers (OTAs) and capacitors has been implemented in monolithic form

Localized surface plate modes via flexural Mie resonances

1 min read ·
Mohamed Farhat, et al., "Localized surface plate modes via flexural Mie resonances". Physical Review B, 95(17), 2017, 174201. Surface-plasmon polaritons are naturally generated upon excitation of metals with high-frequency electromagnetic waves. However, the concept of spoof plasmons has made it possible to generate plasmoniclike effects in microwave electrodynamics, magnetics, and even acoustics. Similarly, in this paper, the concept of localized surface plate modes (SPMs) is introduced. It is demonstrated that SPMs can be generated on a two-dimensional (clamped or stress-free) cylindrical

Fractal electrochemical microsupercapacitors

1 min read ·
Marinal K. Hota, et al., " Fractal electrochemical microsupercapacitors". Advanced Electronic Materials, 3(10), 20171700185. The first successful fabrication of microsupercapacitors (μ‐SCs) using fractal electrode designs is reported. Using sputtered anhydrous RuO2 thin‐film electrodes as prototypes, μ‐SCs are fabricated using Hilbert, Peano, and Moore fractal designs, and their performance is compared to conventional interdigital electrode structures. Microsupercapacitor performance, including energy density, areal and volumetric capacitances, changes with fractal electrode geometry

A 33fJ/Step SAR capacitance-to-digital converter using a chain of inverter-based amplifiers

1 min read ·
Hesham Omran, et al., "A 33fJ/Step SAR capacitance-to-digital converter using a chain of inverter-based amplifiers". IEEE Transactions on Circuits and Systems I: Regular Papers, 64(2), 2017, 310. Abstract: A 12 - bit energy-efficient capacitive sensor interface circuit that fully relies on capacitance-domain successive approximation (SAR) technique is presented. Analysis shows that for SAR capacitance-to-digital converter (CDC) comparator offset voltage will result in parasitic-dependent conversion errors, which necessitates using an offset cancellation technique. Based on the presented

Experimental demonstration of fractional-order oscillators of orders 2.6 and 2.7

1 min read ·
Ahmed S. Elwakil, et al., "Experimental demonstration of fractional-order oscillators of orders 2.6 and 2.7". Chaos, Solitons & Fractals, 96, 2017, 160. The purpose of this work is to provide an experimental demonstration for the development of sinusoidal oscillations in a fractional-order Hartley-like oscillator. Solid-state fractional-order electric double-layer capacitors were first fabricated using graphene-percolated P (VDF-TrFE-CFE) composite structure, and then characterized by using electrochemical impedance spectroscopy. The devices exhibit the fractional orders of 0.6 and 0.74

Tunable fractional-order capacitor using layered ferroelectric polymers

1 min read ·
Agamyrat Agambayev, et al. "Tunable fractional-order capacitor using layered ferroelectric polymers." AIP Advances 7 (9), 2017, 095202. Pairs of various Polyvinylidene fluoride P(VDF)-based polymers are used for fabricating bilayer fractional order capacitors (FOCs). The polymer layers are constructed using a simple drop casting approach. The resulting FOC has two advantages: It can be easily integrated with printed circuit boards, and its constant phase angle (CPA) can be tuned by changing the thickness ratio of the layers. Indeed, our experiments show that the CPA of the fabricated FOCs can

Self-Biased Differential Rectifier with Enhanced Dynamic Range for Wireless Powering

1 min read ·
Mahmoud H. Ouda, et al., "Self-biased differential rectifier with enhanced dynamic range for wireless powering." IEEE Transactions on Circuits and Systems II: Express Briefs 64, (5), 2017, 515. A self-biased cross-coupled differential rectifier is proposed with enhanced power-conversion efficiency (PCE) over an extended range of input power. A prototype is designed for ultrahigh-frequency (UHF) 433-MHz radio-frequency power-harvesting applications and is implemented using a 0.18-μm CMOS technology. The proposed rectifier architecture is compared with the conventional cross-coupled rectifier

Transparent Flash Memory Using Single Ta2O5 Layer for Both Charge-Trapping and Tunneling Dielectrics

1 min read ·
Mrinal K. Hota, et al., "Transparent Flash Memory Using Single Ta2O5 Layer for Both Charge-Trapping and Tunneling Dielectrics." A CS applied materials & interfaces 9 (26), 2017, 21856. We report reproducible multibit transparent flash memory in which a single solution-derived Ta2O5 layer is used simultaneously as a charge-trapping layer and a tunneling layer. This is different from conventional flash memory cells where two different dielectric layers are typically used. Under optimized programming/erasing operations, the memory device shows excellent programmable memory characteristics with a

A New Design Methodology for Time-Based Capacitance-to-Digital Converters (T-CDCs)

1 min read ·
Ali H. Hassan, et al., "A New Design Methodology for Time-Based Capacitance-to-Digital Converters (T-CDCs)". AEU-International Journal of Electronics and Communications 96, 2018, 238. This paper introduces a 9-bit time-based capacitance-to-digital converter (T-CDC). This T-CDC adopts a new design methodology for parasitic cancellation with a simple calibration technique. In T-CDCs, the input sensor capacitance is first converted into a delay pulse using a capacitance-to-time converter (CTC) circuit; then this delay signal is converted into a digital code through a time-to-digital converter

Electronically tunable fully integrated fractional-order resonator

1 min read ·
Georgia Tsirimokou., et al., "Electronically tunable fully integrated fractional-order resonator". I EEE Transactions on Circuits and Systems II: Express Briefs, 65(2), 2017, 166. A fully integrated implementation of a parallel fractional-order resonator that employs together a fractional-order capacitor and a fractional-order inductor is proposed in this brief. The design utilizes current-controlled operational transconductance amplifiers as building blocks, designed, and fabricated in AMS 0.35-μm CMOS process and based on a second-order approximation of a fractional-order differentiator

Experimental Verification of a Fractional-Order Wien Oscillator Built Using Solid-State Capacitors

1 min read ·
Kartci, Aslihan, et al. "Experimental Verification of a Fractional-Order Wien Oscillator Built Using Solid-State Capacitors." 2018 IEEE 61st International Midwest Symposium on Circuits and Systems (MWSCAS). IEEE, 2018, 544. A new type of fractional-order capacitors (FOCs) is fabricated using a molybdenum disulfide (MoS 2 )-ferroelectric polymer composite. The phase angle of this FOC's impedance remains constant between 100 Hz and 10MHz with only a small deviation of ±4 degrees. The performance of the fabricated FOCs is further tested using the well-known Wien oscillator. The main motivation of

An ultra-broadband single-component fractional-order capacitor using MoS2-ferroelectric polymer composite

1 min read ·
Agamyrat Agambayev, et al., "An ultra-broadband single-component fractional-order capacitor using MoS2-ferroelectric polymer composite". Applied Physics Letters, 113(9),2018, 093505. The phase angle of a fractional-order capacitor's (FOC) impedance has a constant value between −90°−90° and 0°0°. Maintaining this value over a broad frequency band is of utmost importance since it increases the applicability of the electrical circuit that employs the fractional-order capacitor (FOC). In this work, a molybdenum disulfide (MoS2)-ferroelectric polymer composite is used to design/fabricate an FOC

ASIC oriented comparative analysis of biologically inspired neuron models

1 min read ·
El-Maksoud, Ahmed J. Abd, et al. "ASIC oriented comparative analysis of biologically inspired neuron models." 2018 IEEE 61st International Midwest Symposium on Circuits and Systems (MWSCAS). IEEE, 2018, 504. This paper introduces the hardware and the ASIC implementations of the four most popular biologically inspired neuron models. The models are quartic, Izhikevich, Hindmarsh Rose and Fitzhugh-Nagumo. Moreover, some approximate computing techniques are applied on these models to reduce the area and power consumption. In addition, ASIC implementations of these models and their approximate

CMOS-RC Colpitts oscillator design using floating fractional-order inductance simulator

1 min read ·
Kartci, Aslihan, et al. "CMOS-RC Colpitts oscillator design using floating fractional-order inductance simulator." IEEE 61st International Midwest Symposium on Circuits and Systems (MWSCAS). IEEE, 2018, 905. This paper deals with CMOS fractional-order inductance (FoL) simulator design and its utilization in 2.75 th order Colpitts oscillator providing high frequency of oscillation. The proposed floating FoL is composed of two unity-gain current followers (CF±s), two inverting voltage buffers, a transconductor, and a fractional-order capacitor (FoC) of order 0.75, while the input intrinsic

A Comparative Study of Interdigitated Electrode and Quartz Crystal Microbalance Transduction Techniques for Metal–Organic Framework-Based Acetone Sensors

1 min read ·
Chappanda N. Karumbaiah, et al., "A Comparative Study of Interdigitated Electrode and Quartz Crystal Microbalance Transduction Techniques for Metal–Organic Framework-Based Acetone Sensors". Sensors 18(11), 2018, 3898. We present a comparative study of two types of sensor with different transduction techniques but coated with the same sensing material to determine the effect of the transduction mechanism on the sensing performance of sensing a target analyte. For this purpose, interdigitated electrode (IDE)-based capacitors and quartz crystal microbalance (QCM)-based resonators were coated with

Guest Editorial: Special Issue on Large-Scale Memristive Systems and Neurochips for Computational Intelligence

1 min read ·
Alex Pappachen James, et al., "Guest Editorial: Special Issue on Large-Scale Memristive Systems and Neurochips for Computational Intelligence". IEEE Transactions on Emerging Topics in Computational Intelligence, 2(5), 2018, 320. Abstract: The papers in this special section explore the use of large scale memristive systems and neurochips for computational intelligence. The interest in the application of memristor device as a memory element, neuromorphic device, as a sensor and as a switch for programmable logic circuits has been growing in the last decade. The small size, ease of

Fully printed 3D cube-shaped multiband fractal rectenna for ambient RF energy harvesting

1 min read ·
Azamat Bakytbekov, A, et al., "Fully printed 3D cube-shaped multiband fractal rectenna for ambient RF energy harvesting". Nano energy, 53, 2018, 587. The Internet of Things (IoT) is an emerging paradigm that requires billions of wirelessly connected devices in a complex radio-frequency (RF) environment. With such a huge number of devices in this scenario, recharging or replacing batteries becomes impractical. Therefore, powering IoT devices by harvesting energy from ambient sources, such as that available in the RF spectrum, is an attractive solution. The antenna for the RF energy harvester

Towards fractional-order capacitors with broad tunable constant phase angles: Multi-walled carbon nanotube-polymer composite as a case study

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Agamyrat Agambayev, et al., "Towards fractional-order capacitors with broad tunable constant phase angles: Multi-walled carbon nanotube-polymer composite as a case study." Journal of Physics D: Applied Physics 51(6), 2018, 065602. In this study, multi-walled carbon nanotube (MWCNT) filled polyevinelidenefluoride-trifluoroethylene-chlorofluoroethylene composites are used to realize fractional-order capacitors (FOCs). A solution-mixing and drop-casting approach is used to fabricate the composite. Due to the high aspect ratio of MWCNTs, percolation regime starts at a small weight percentage (wt%)

An approximate multiplier based hardware implementation of the izhikevich model

1 min read ·
Hassan, Salma, et al., "An approximate multiplier based hardware implementation of the izhikevich model." IEEE 61st International Midwest Symposium on Circuits and Systems (MWSCAS). IEEE, 2018, 492. This paper proposes the use of approximate multipliers in the hardware implementation of Izhikevich spiking neuron model. The accuracy of the model is investigated by calculating various types of errors on a single neuron and this analysis shows that the proposed model follows the original model. It shows that the proposed model reproduces the same firing patterns as the original one. The network

Analog backpropagation learning circuits for memristive crossbar neural networks

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Krestinskaya, Olga, "Analog backpropagation learning circuits for memristive crossbar neural networks." 2018 IEEE International Symposium on Circuits and Systems (ISCAS). IEEE, 2018, 1. The implementation of backpropagation algorithm using gradient descent operation with analog circuits is an open problem. In this paper, we present the analog learning circuits for realizing backpropagation algorithm for use with neural networks in memristive crossbar arrays. The circuits are simulated in SPICE using TSMC 180nm CMOS process models, and HP memristor models. The gradient descent operations are

Fractional-Order Hartley Oscillator.

1 min read ·
Agambayev, A., et al., "Fractional-Order Hartley Oscillator". PRIME, 2018, 45. A fractional-order capacitor (FOC) is developed using a Molybdenum disulfide ferroelectric polymer composite. The fabricated FOC exhibits constant phase over five decades between 100 Hz-10 MHz, which is the broadest operating frequency bandwidth reported so far for an FOC. Furthermore, a fractional-order Hartley oscillator is built using this FOC, and provide ten times higher oscillation frequency than the frequency of the conventional Hartley oscillator counterpart.

Learning in Memristive Neural Network Architectures Using Analog Backpropagation Circuits

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Olga Krestinskaya, et al., "Learning in Memristive Neural Network Architectures Using Analog Backpropagation Circuits" IEEE Transactions on Circuits and Systems-I 66 (2), 2019, 719. The on-chip implementation of learning algorithms would speed up the training of neural networks in crossbar arrays. The circuit level design and implementation of a back-propagation algorithm using gradient descent operation for neural network architectures is an open problem. In this paper, we propose analog backpropagation learning circuits for various memristive learning architectures, such as deep neural

Approximate Computing With Stochastic Transistors’ Voltage Over-Scaling

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Ren Li, et al., "Approximate Computing With Stochastic Transistors’ Voltage Over-Scaling" IEEE Access 7, 2019, 6373. Ubiquitous computing and the ever-rising need for energy efficiency pose challenges in terms of the processing requirements and the corresponding machine complexity. Nonetheless, the nature of the underlying applications, particularly dealing with real-world data, offers alternative paradigms toward the efficient utilization of the available design resources. In this paper, approximate computing is addressed as an accommodating technique that can benefit from the inherent

Low-Power Hardware Implementation of a Support Vector Machine Training and Classification for Neural Seizure Detection

1 min read ·
Heba Elhosary, et al., "Low-Power Hardware Implementation of a Support Vector Machine Training and Classification for Neural Seizure Detection." IEEE Transactions on Biomedical Circuits and Systems 13 (6), 2019, 1324. In this paper, a low power support vector machine (SVM) training, feature extraction, and classification algorithm are hardware implemented in a neural seizure detection application. The training algorithm used is the sequential minimal optimization (SMO) algorithm. The system is implemented on different platforms: such as field programmable gate array (FPGA), Xilinx Virtex-7 and

Scattering Cancellation-based Cloaking for the Maxwell-Cattaneo Heat Waves

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Mohamed Farhat, et al., "Scattering Cancellation-based Cloaking for the Maxwell-Cattaneo Heat Waves". Physical Review Applied, 11(4), 2019, 044089. We theoretically propose scattering cancellation-based cloaks for heat waves that obey the Maxwell-Cattaneo equation. The proposed cloaks possess carefully tailored diffusivity to cancel the dipole scattering from the object that they surround, and thus can render a small object invisible in the near and far fields, as demonstrated by full-wave finite-element simulations. Mantle heat cloaking is further analyzed and proposed to simplify the design

Synthesis and Optimization of Fractional-order Elements Using a Genetic Algorithm

1 min read ·
Aslihan Kartci, et al., "Synthesis and Optimization of Fractional-order Elements Using a Genetic Algorithm". IEEE Access 7, 2019, 80233. This study proposes a new approach for the optimization of phase and magnitude responses of fractional-order capacitive and inductive elements based on the mixed integer-order genetic algorithm (GA), over a bandwidth of four-decade, and operating up to 1 GHz with a low phase error of approximately ±1 ◦ . It provides a phase optimization in the desired bandwidth with minimal branch number and avoids the use of negative component values, and any complex

FPGA Implementation of Dynamically Reconfigurable IoT security Module Using Algorithm Hopping

1 min read ·
Shady Soliman, et al., "FPGA Implementation of Dynamically Reconfigurable IoT security Module Using Algorithm Hopping." Integration 68, 2019, 108. Internet of Things (IoT) is a promising technology that is continuously spreading around the world leading to many challenges facing cryptographic designers who are trying to fulfill the security standards of IoT constrained devices. In this work, a new design is proposed that adds a new dimension of security by using the concept of frequency hopping to generate a pseudo-random pattern for switching between 5 lightweight cryptographic ciphers: AEGIS

An Imperceptible Magnetic Skin

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Abdullah S Almansouri, et al., "An Imperceptible Magnetic Skin." Advanced Materials Technologies 4 (10), 2019, 1900493. Flexible and wearable magnetoelectronics add intriguing new functionalities to natural perception. Of particular interest regarding these artificial skins are wireless sensing and touchless interactions. Biocompatibility and imperceptibility are the most significant features of devices attached to the bodies. A biocompatible magnetic skin is introduced. It offers extreme flexibility, stretchability (>300%), and is lightweight, while maintaining a remanent magnetization up to

An Ultra-Area-Efficient 1024-Point In-Memory FFT Processor

1 min read ·
Hasan E. Yantir, et al., "An Ultra-Area-Efficient 1024-Point In-Memory FFT Processor", Micromachines, 10 (8), 2019, 509. Current computation architectures rely on more processor-centric design principles. On the other hand, the inevitable increase in the amount of data that applications need forces researchers to design novel processor architectures that are more data-centric. By following this principle, this study proposes an area-efficient Fast Fourier Transform (FFT) processor through in-memory computing. The proposed architecture occupies the smallest footprint of around 0.1 mm2 inside

Scattering Theory of Gravity-Flexural Waves of Floating Plates on Water

1 min read ·
Mohamed Farhat, et al., "Scattering Theory of Gravity-Flexural Waves of Floating Plates on Water". arXiv preprint arXiv:1901.09733. Phys. Rev. B 101, 2019, 014307. We combine theories of scattering for linearized water waves and flexural waves in thin plates to characterize and achieve control of water wave scattering using floating plates. This requires manipulating a sixth-order partial differential equation with appropriate boundary conditions of the velocity potential. Making use of multipole expansions, we reduce the scattering problem to a linear algebraic system. The response of a

A Comparison of Artificial Neural Network (ANN) and Support Vector Machine (SVM) Classifiers for Neural Seizure Detection

1 min read ·
Elgammal, M, et al., "A Comparison of Artificial Neural Network (ANN) and Support Vector Machine (SVM) Classifiers for Neural Seizure Detection". IEEE 62nd International Midwest Symposium on Circuits and Systems (MWSCAS) 2019, 646. In this paper, two different classifiers are software and hardware implemented for neural seizure detection. The two techniques are support vector machine(SVM) and artificial neural networks(ANN). The two techniques are pretrained on software and only the classifiers are hardware implemented and tested. A comparison of the two techniques is performed on the levels

A Precision, Energy-Efficient, Oversampling, Noise-Shaping Differential SAR Capacitance-to-Digital Converter

1 min read ·
Abdulaziz Alhoshany, et al., "A Precision, Energy-Efficient, Oversampling, Noise-Shaping Differential SAR Capacitance-to-Digital Converter" IEEE Transactions on Instrumentation and Measurement, 68 (2), 2019, 392. This paper introduces an oversampling, noise-shaping differential successive-approximation-register capacitance-to-digital converter (CDC) architecture for interfacing capacitive sensors. The proposed energy-efficient CDC achieves high-precision capacitive resolution by employing oversampling and noise shaping. The switched-capacitor (SC) integrator is inserted between the comparator

Photo-carrier Extraction by Triboelectricity for Carrier Transport Layer-free Photodetectors

1 min read ·
Vincent K. S. Hsiao, et al., "Photo-carrier Extraction by Triboelectricity for Carrier Transport Layer-free Photodetectors." Nano Energy 65, 2019, 103958. Efficient carrier extraction is essential for high performance optoelectronic devices, such as solar cells and photodetectors. Conventional strategies to separate photogenerated carriers typically involve the fabrication of a p-n junction by doping and the use of carrier selective charge transport layers. However, these techniques often require high temperature processes or costly materials. In this work, we demonstrate an innovative and

A Self-Powered Magneto-Acoustic Tracking Transducer

1 min read ·
Almansouri, Abdullah S., et al. "A Self-Powered Magneto-Acoustic Tracking Transducer." (2020). Acoustic telemetry is widely used for many tracking applications. Objects or subjects are tracked by attaching an acoustic transmitter onto them or having them wear them. The acoustic signal is then detected by different microphones to determine the location of the tagged target. The size and the weight of the tag determine the size of the target that can be tracked. In the case of small-sized tags, about 80% of the volume is consumed by the battery and electronics, while less than 20% by the actual

Spectrometer-Free Graphene Plasmonics Based Refractive Index Sensor

1 min read ·
Li Zhang, et al., "Spectrometer-Free Graphene Plasmonics Based Refractive Index Sensor." Sensors 20 (8), 2020, 2347. We propose a spectrometer-free refractive index sensor based on a graphene plasmonic structure. The spectrometer-free feature of the device is realized thanks to the dynamic tunability of graphene’s chemical potential, through electrostatic biasing. The proposed sensor exhibits a 1566 nm/RIU sensitivity, a 250.6 RIU− 1 figure of merit in the optical mode of operation and a 713.2 meV/RIU sensitivity, a 246.8 RIU− 1 figure of merit in the electrical mode of operation. This

Blue Energy Fuels: Converting Ocean Wave Energy to Carbon-based Liquid Fuels via CO2 Reduction

1 min read ·
Siu-Fung Leung, et al., "Blue Energy Fuels: Converting Ocean Wave Energy to Carbon-based Liquid Fuels via CO2 Reduction." Energy & Environmental Science, 2020. Sequestering CO2 in the form of carbon-based liquid fuels would provide both a convenient and sustainable form of energy for practical use as well as mitigate the effects of global warming and climate change. Ocean wave energy is an abundant and relatively stable source of renewable energy, which would be highly desirable for the conversion of CO2 to conveniently stored and transported liquid fuels. In this work, we demonstrate a wave

Scattering theory and cancellation of gravity-flexural waves of floating plates

1 min read ·
Mohamed Farhat, et al., "Scattering theory and cancellation of gravity-flexural waves of floating plates." Physical Review B, 101 (1), 2020, 014307. We combine theories of scattering for linearized water waves and flexural waves in thin elastic plates to characterize and achieve control of water wave scattering using floating plates. This requires manipulating a sixth-order partial differential equation with appropriate boundary conditions of the velocity potential. Making use of multipole expansions, we reduce the scattering problem to a linear algebraic system. The response of a floating

A Dual-Mode Nested Rectifier for Ambient Wireless Powering in CMOS Technology

1 min read ·
Abdullah Almansouri, et al., "A Dual-Mode Nested Rectifier for Ambient Wireless Powering in CMOS Technology." IEEE Transactions on Microwave Theory and Techniques, 68 (5) , 2020, 1754. This article proposes (DM) nested radio frequency (RF) rectifier for ambient wireless powering. The proposed architecture utilizes a DM nested feedback circuit to enhance the conductivity of the rectifier at low power while reducing the reverse leakage current at high power by generating supply voltages at the gates of the pMOS rectifying transistors. The proposed rectifier is fabricated in a 65-nm CMOS

Toward Self-Powered Internet of Underwater Things Devices

1 min read ·
Jose de Oliveira, et al., "Toward Self-Powered Internet of Underwater Things Devices." IEEE Communications Magazine 58 (1), 2020, 68. Exploiting light beams to carry information and deliver power is suggested as a potential technology to recharge batteries in future generations of IoT and IoUT devices while providing optical connectivity. SLIPT has been recently proposed as an efficient method of wireless power transfer between communicating terminals. In this article, we provide an overview of the various SLIPT techniques in the time, power, and space domains. We also demonstrate two SLIPT

Fully Transparent Transceiver Using Single Binary Oxide Thin Film Transistors

1 min read ·
Ali Hassan, et al., "Fully Transparent Transceiver Using Single Binary Oxide Thin Film Transistors." Advanced Electronic Materials 6, 2020, 1901083. Using one binary oxide, a fully transparent thin‐film transistor (TFT)‐based transceiver circuit is presented. The proposed transceiver circuit is fabricated entirely using an atomic layer deposition process. Moreover, the proposed circuit presents two modulation schemes: frequency shift keying and ON/OFF keying. The fabricated TFTs exhibit saturation mobility, threshold voltage, a subthreshold swing, and an ON/OFF ratio of 18.2 cm 2 V− 1 s− 1, 0

Ultra miniaturized InterDigitated electrodes platform for sensing applications

1 min read ·
Z. Wang, et al., "Ultra miniaturized InterDigitated electrodes platform for sensing applications." Microelectronic Engineering 225, 2020, 111253. InterDigitated Electrodes (IDEs) is a generic platform for a wide range of diverse applications with their implementation in sensing modules being a major one. We propose the use of IDCs with deep sub-micron critical dimension; equally spaced electrodes of 200 nm width for enhanced sensing performance and also the method of fabrication thereof. The transducer configuration was studied theoretically with a finite element method simulation by using

EANN: Energy Adaptive Neural Networks

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Salma Hassan, et al., "EANN: Energy Adaptive Neural Networks." Electronics 9 (5), 2020, 746. This paper proposes an Energy Adaptive Feedforward Neural Network (EANN). It uses multiple approximation techniques in the hardware implementation of the neuron unit. The used techniques are precision scaling, approximate multiplier, computation skipping, neuron skipping, activation function approximation and truncated accumulation. The proposed EANN system applies the partial dynamic reconfiguration (PDR) feature supported by the FPGA platform to reconfigure the hardware elements of the neural network

Simplified Modal‐Cancellation Approach for Substrate‐Integrated‐Waveguide Narrow‐Band Filter Design

1 min read ·
Sebastian Celis, et al., "Simplified Modal-Cancellation Approach for Substrate-Integrated-Waveguide Narrow-Band Filter Design". Electronics 2020, 9, 962. Current substrate-integrated-waveguide (SIW) filter design methodologies can be extremely computational and time-inefficient when a narrow-band filter is required. A new approach to designing compact, highly selective narrow-band filters based on smartly positioned obstacles is thus presented here. The proposed modal-cancellation approach is achieved by translating or eliminating undesired modes within the frequency of interest. This is

Organic Field-Effect Transistor-Based Flexible Sensors

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Saravanan Yuvaraja et al., "Organic Field-Effect Transistor-Based Flexible Sensors" Chemical Society Reviews 2020, (Advanced Article). (12) 49, 2020, 3423. Flexible electronic devices have attracted a great deal of attention in recent years due to their flexibility, reduced complexity and lightweight. Such devices can conformably attach themselves to any bendable surface and can possess diverse transduction mechanisms. Consequently, with continued emphasis on innovation and development, major technological breakthroughs have been achieved in this area. This review focuses on the advancements

Towards Efficient Neuromorphic Hardware: Unsupervised Adaptive Neuron Pruning

1 min read ·
Wenzhe Guo, et al., "Towards Efficient Neuromorphic Hardware: Unsupervised Adaptive Neuron Pruning". Electronics 9, 2020, 1059. To solve real-time challenges, neuromorphic systems generally require deep and complex network structures. Thus, it is crucial to search for effective solutions that can reduce network complexity, improve energy efficiency, and maintain high accuracy. To this end, we propose unsupervised pruning strategies that are focused on pruning neurons while training in spiking neural networks (SNNs) by utilizing network dynamics. The importance of neurons is determined by the

Efficient Acceleration of Stencil Applications through In-Memory Computing

1 min read ·
Hasan Yantır, et al., "Efficient Acceleration of Stencil Applications through In-Memory Computing". Micromachines 11, 2020, 622. The traditional computer architectures severely suffer from the bottleneck between the processing elements and memory that is the biggest barrier in front of their scalability. Nevertheless, the amount of data that applications need to process is increasing rapidly, especially after the era of big data and artificial intelligence. This fact forces new constraints in computer architecture design towards more data-centric principles. Therefore, new paradigms such as in

Automating Analogue AI Chip Design with Genetic Search

1 min read ·
Olga Krestinskaya, et al., "Automating Analogue AI Chip Design with Genetic Search" Adv. Intell. Syst, 2000075, 2020, 2. Optimization of analogue neural circuit designs is one of the most challenging, complicated, time‐consuming, and expensive tasks. Design automation of analogue neuromemristive chips is made difficult by the need to design chips at low cost, ease of scaling, high‐energy efficiency, and small on‐chip area. The rapid progress in edge AI computing applications generates high demand for developing smart sensors. The integration of high‐density analogue computing AI chips as

Growth of large-scale MoS2 nanosheets on double layered ZnCo2O4 for real-time in-situ H2S monitoring in live cells

1 min read ·
Mani Veerappan et al., "Growth of large-scale MoS2 nanosheets on double layered ZnCo2O4 for real-time in-situ H2S monitoring in live cells"Journal of Materials Chemistry B, 2020, 1. There is an urgent need to develop in-situ sensors that monitor the continued release of H2S from biological systems to understand H2S-related pathology and pharmacology. For this purpose, we have developed a molybdenum disulfide supported double-layered zinc cobaltite modified carbon cloth electrode (MoS2–ZnCo2O4–ZnCo2O4) based electrocatalytic sensor. The results of our study suggest that the MoS2–ZnCo2O4–ZnCo2O4

Multi‐source ambient energy harvester based on RF and thermal energy: Design, testing, and IoT application

1 min read ·
Azamat Bakytbekov, et al., "Multi‐source ambient energy harvester based on RF and thermal energy: Design, testing, and IoT application." Energy Science & Engineering, 2020,1. Billions of wireless sensing devices must be powered for IoT applications. Collecting energy from the ambient environment to power sensor nodes is a promising solution. Solar energy has been one of the main sources of ambient energy due to its availability, higher power density, and the maturity of the solar photovoltaic industry. However, there are many scenarios (indoor environment, outdoor environment during nighttime

A multi-bit fully integrated thin-film transistor NO2 gas detector at room temperature

1 min read ·
Mani Teja, et al., “A multi-bit fully integrated thin-film transistor NO2 gas detector at room temperature”, IEEE sensor letters 4 (8), 2020, 5501204. Inexpensive and compact gas sensing systems are indispensable for accurate air quality monitoring with broad spatial coverage. We report an InGaZnO thin-film transistor (TFT)-based integrated NO 2 gas detection system that yields a digital output proportional to the NO 2 concentration. This is the first report on integrated TFT-based detectors where gas concentration is quantified and where simultaneous digital output is provided without

Numerical modeling for terahertz testing of non-metallic pipes

1 min read ·
Mohammed Farhat et al., "Numerical modeling for terahertz testing of non-metallic pipes" AIP Advances 10, 2020, 095112. In the oil and gas industry, safety and operational efficiency at production sites are of paramount importance. A reliable non-destructive testing technology for non-metallic pipes has a high potential financial impact, since it may facilitate the replacement of metallic pipes with non-metallic ones. This article features a perspective and future trends in the field of terahertz sensing technology. Importantly, several numerical simulations that illustrate many exciting

Polarization Insensitive and Transparent Frequency Selective Surface for Dual Band GSM Shielding

1 min read ·
Yiming Yang, et al., "Polarization Insensitive and Transparent Frequency Selective Surface for Dual Band GSM Shielding." IEEE Transactions on Antennas and Propagation, 2020 This paper proposes a single-layer, dual-band, optically transparent frequency selective surface (FSS) for GSM shielding. The design evolves from a fractal cross dipole to achieve dual band response, polarization insensitivity and wide angle of incidence stability with a miniaturized size. A two-axis symmetric structure helps to provide a stable frequency response for incident waves with different polarization angles up to

Rail-to-rail complementary input StrongARM comparator for low-power applications

1 min read ·
Mohammed Al Qadasi., et al. "Rail-to-rail complementary input StrongARM comparator for low-power applications." IET Circuits, Devices & Systems, 2020. This study proposes a new scheme for rail-to-rail input StrongARM latch comparator. Additional differential input p-type metal-oxide-semiconductor (PMOS) and cross-coupled n-type metal-oxide-semiconductor (NMOS) transistors have been introduced to achieve the rail-to-rail input range. The proposed scheme offers low-energy consumption of 15.2 fJ and a high speed of 3 GHz, which makes it attractive for energy harvested Internet of Thing

Unsupervised adaptive weight pruning for energy-efficient neuromorphic systems Frontiers in Neuroscience, section Neuromorphic Engineering.

1 min read ·
Wenzhe Guo, et al., "Unsupervised Adaptive Weight Pruning for Energy-Efficient Neuromorphic Systems." Frontiers in Neuroscience 14, 2020, 1189. To tackle real-world challenges, deep and complex neural networks are generally used with a massive number of parameters, which require large memory size, extensive computational operations, and high energy consumption in neuromorphic hardware systems. In this work, we propose an unsupervised online adaptive weight pruning method that dynamically removes non-critical weights from a spiking neural network (SNN) to reduce network complexity and improve