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Electronics Letters

Issue 18 • Date August 29 2013

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Displaying Results 1 - 25 of 48
  • In brief

    Publication Year: 2013 , Page(s): 1112
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (325 KB)  

    Provides an overview of the technical articles and features presented in this issue. View full abstract»

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  • Interview [Carlos Thomaz]

    Publication Year: 2013 , Page(s): 1112
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (228 KB)  

    Dr. Carlos Thomaz from Centro Universitario da FEI, Brazil, talks about the research behind his paper "A priori-driven multivariate statistical approach to reduce dimensionality of MEG signals." View full abstract»

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  • Tuning with finesse [Broadband comb sources tuned via intracavity Fabry-Perot etalon]

    Publication Year: 2013 , Page(s): 1113
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (806 KB)  

    Researchers at the Purdue University Ultrafast Optics and Optical Fiber Communications Laboratory in the US have reported tuning of the frequency envelope of a broadband comb source at 1.5-μm, generated from a semiconductor-based mode-locked ring laser with an intracavity high finesse Fabry-Perot etalon. Broadband, stable spectral comb sources find use in a number of applications, such as multiwavelength light sources, multi-channel dense WDM transmission, microwave photonic filters or signal processors and high speed optical communications. Wavelength tuning of such sources will lend flexibility in the device's operation and may reduce the cost of system implementation by allowing the use of cheap passive and fixed counterpart components. View full abstract»

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  • Taking the heat

    Publication Year: 2013 , Page(s): 1114
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (998 KB)  

    A team at the University of Louisiana at Lafayette in the US have created a thin film of silica aerogel on a silicon wafer and have demonstrated its potential to make more efficient metal oxide semiconductor (MOX) gas sensors. View full abstract»

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  • 3D printing technique for fabrication of frequency selective structures for built environment

    Publication Year: 2013 , Page(s): 1117 - 1118
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (362 KB)  

    The frequency selectivity of an array of triple cross elements fabricated using an additive manufacturing technique is assessed, to demonstrate the feasibility of using three-dimensional (3D) printing techniques in frequency selective structure production. The process is a candidate for the fabrication of frequency sensitive components in buildings, in situations where the electromagnetic architecture is an important consideration. As a simple symmetrical 3D element, the triple cross is part of a class of elements suitable for crystal-like configurations. The basic performance of the array is summarised through simulations and experimental results. View full abstract»

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  • Compact tri-band CPW-fed antenna for WLAN/WiMAX applications

    Publication Year: 2013 , Page(s): 1118 - 1119
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (273 KB)  

    A compact triple-band coplanar waveguide (CPW)-fed antenna for WLAN/WiMAX applications is proposed. The radiation patch is fed by capacitive coupling of the top transmission line. By only using one metallic strip etched on the bottom of the substrate, tri-band resonances of the antenna are generated. The proposed antenna has a compact size of 30 × 27 mm2, which can provide stable omnidirectional radiation patterns in three bands. The measured - 10 dB impedance bandwidths are 150 MHz (2.39-2.54 GHz), 360 MHz (3.37-3.73 GHz) and 1170 MHz (5.02-6.19 GHz), which is suitable for WLAN/WiMAX applications. View full abstract»

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  • Double-slot Vivaldi antenna with improved gain

    Publication Year: 2013 , Page(s): 1119 - 1121
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (594 KB)  

    A double-slot structure is proposed to design a new Vivaldi antenna with improved gain. The two slots are excited in uniform amplitude and phase by using a T-junction power divider. The double-slot structure can generate plane-like waves across the slot aperture of the antenna. As a result, the gain of the double-slot Vivaldi antenna is significantly improved compared with that of a typical Vivaldi antenna of the same size. The measured results show that the impedance bandwidth of the double-slot Vivaldi antenna is from 2.5 to 15 GHz. The gain of the proposed antenna is considerably higher than the typical antenna at frequencies above 6 GHz. What is more, the structure proposed is far simpler than those designed before. View full abstract»

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  • Miniaturised two-layer slit-patch structure for decoupling printed antennas

    Publication Year: 2013 , Page(s): 1121 - 1123
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (498 KB)  

    A miniaturised double-layer slit-patch structure is introduced for decoupling two closely spaced co-planar waveguide-fed printed monopoles with a common ground. The double-layer structure consists of a slit etched on the common ground between the antennas and a conducting dipole element printed on a very thin dielectric film separating the two layers. Simulated results of the antennas' performance as well as measurements of fabricated prototypes are presented. View full abstract»

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  • A priori-driven multivariate statistical approach to reduce dimensionality of MEG signals

    Publication Year: 2013 , Page(s): 1123 - 1124
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (280 KB)  

    A magnetoencephalography (MEG) multivariate data exploratory analysis is described and implemented that combines the variance criterion used in principal component analysis with some prior knowledge about the sensory experimental task. By using the idea of rearranging the data matrix in classification pairs that correspond to the time-varying representation of either stable or stimulus phases of the specific task, the feature extraction method is constrained reducing significantly the number of principal components necessary to represent most of the total variance explained by the MEG signals. View full abstract»

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  • High-performance wide-VDDH-range level converter for mixed-signal systems

    Publication Year: 2013 , Page(s): 1125 - 1126
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (238 KB)  

    A high-performance wide-VDDH-range level converter (LC) is presented for mixed-signal systems. The proposed LC achieves a low power-delay product over a wide range of VDDH with VDDL in the near-threshold region. The proposed LC uses a feed-forward signal to pull down the output voltage at low VDDH, without increasing the size of the nMOS diode for the pseudo-VDDL. A comparison with conventional LCs shows that the proposed LC not only supports high VDDH but is also robust at low VDDH while exhibiting high performance. View full abstract»

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  • Low-noise and high-gain wideband lna with gm-boosting technique

    Publication Year: 2013 , Page(s): 1126 - 1128
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (349 KB)  

    A broadband low-noise amplifier (LNA) is proposed. The active gm-boosting technique is utilised to reduce the common-gate (CG) LNA noise figure and improve gain. An implemented prototype using 0.13 μm CMOS technology is evaluated using on-wafer probing. S11 and S22 are below - 10 dB across 0.1-5 GHz. Measurements show a power gain of 18.3 dB with a - 3 dB bandwidth from 100 MHz to 2.1 GHz and an IIP3 of - 7 dBm at 2 GHz. The measured noise figure is better than 2.5 dB below 2.1 GHz, better than 4.5 dB below 5 GHz and at 500 MHz it obtains its minimum value 1.8 dB. The LNA consumes 14 mW from 1.5 V supply and occupies an area of 0.04 mm2. View full abstract»

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  • Wien bridge-based calibration circuit for CDR applications

    Publication Year: 2013 , Page(s): 1128 - 1130
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (158 KB)  

    A robust and fully integrated solution to calibrate the voltage controlled oscillator frequency to the data rate frequency in a clock and data recovery is described. As such, no external reference frequency or a separate reference phase-locked loop is required. The proposed calibration circuit has been designed in a 130 nm CMOS technology. It shows a very low temperature dependency below 100 ppm °C-1. View full abstract»

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  • Clock buffer with supply noise active compensation for reduced period jitter

    Publication Year: 2013 , Page(s): 1130 - 1131
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (352 KB)  

    A simple circuit that actively compensates supply noise and reduces period jitter in CMOS clock buffers is presented. The locally sensed supply noise modulates a current injected in the buffer output node during transitions. By injecting the current in opposite phase to the supply noise, the transient variations are counterbalanced and the jitter removed. Designed in a 28 nm CMOS technology, a chain of 16 inverters using the proposed circuit shows a period jitter up to three times smaller than that of an equally long chain of basic inverters. Conventional local supply noise filtering would require approximately 70 times the area used by the proposed circuit to achieve similar performance. View full abstract»

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  • Design of four-state inverter using quantum dot gate-quantum dot channel field effect transistor

    Publication Year: 2013 , Page(s): 1131 - 1133
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (395 KB)  

    Quaternary logic can be implemented using quantum dot gate-quantum dot channel field effect transistors (QDG-QDCFETs) which produce four states in their transfer characteristics. A circuit model is used to simulate a four-state state inverter which is the basic building block of any multi-valued logic (MVL) circuit design. A basic problem of MVL implementation is the noise margin. The stable nature of the transfer characteristics of the QDG-QDCFET can make them a promising circuit element in future MVL circuit design. Comparison of fabricated device characteristics and the model data is shown. View full abstract»

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  • Low complexity lowpass linear-phase multiplierless FIR filter

    Publication Year: 2013 , Page(s): 1133 - 1135
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (254 KB)  

    A new class of lowpass linear-phase FIR filter function given in an explicit compact form is introduced. First, the general form of a new class of nth-order difference equations with all real coefficients equals one is proposed, and after that the simple frequency sampling structure for any odd and even orders of the filter is designed. Finally, several simulation experiments have been performed in order to compare this filter with other known filters for the same values of free real integer parameters. It should be highlighted that the new filters compare favourably even with the already existing filters, because they have an insert attenuation of 158 dB, 15.1681% lower cutoff frequency of the passband of the filter, and 18.5313% lower cutoff frequency of the stopband of the filter, for an insert loss of 100 dB. View full abstract»

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  • Unified split-step precise integration timedomain method for dispersive media

    Publication Year: 2013 , Page(s): 1135 - 1136
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (155 KB)  

    Based on the use of auxiliary differential equations, a unified split-step precise integration time-domain (SS-PITD) method is proposed for modelling wave propagation in linear dispersive media. The unification of this method is achieved by using a general expression to represent the Debye, Lorentz and Drude dielectric medium models. Moreover, due to the introduction of the SS scheme, the original two-dimensional (2D) or 3D electromagnetic problem reduces to a set of 1D sub-problems which can be efficiently solved by using the conventional PITD algorithm. It leads to a great reduction in the requirement of computation time and storage space. The proposed method is verified with a numerical example and compared with the finite-difference time-domain method. View full abstract»

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  • Fast and efficient blind image quality index in spatial domain

    Publication Year: 2013 , Page(s): 1137 - 1138
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (111 KB)  

    A fast and efficient method [fast efficient blind (FEB)] for no-reference image quality assessment (IQA) is presented. Two new features, log-energy and variance, are proposed in the spatial domain, which make the IQA algorithm faster and more efficient. FEB obviates the training process of distortion images and subjective opinion scores due to the properties of the new features. The experiment shows that the proposed method outperforms conventional methods in terms of both accuracy and execution speed and is also consistent with the subjective assessment of human beings. Owing to the simplicity of the features proposed, FEB can realise real-time IQA completely. View full abstract»

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  • Specularity detection method based on MSER

    Publication Year: 2013 , Page(s): 1138 - 1140
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (183 KB)  

    A new algorithm for specularity detection using a single image, which is based on the maximally stable extremal regions (MSER) detector, is presented. This algorithm takes full advantage of the characteristics of specularity and requires no assumptions. For this reason, it separates specularities very well regardless of the illumination condition and the surface material. To illustrate the effectiveness of the prposed algorithm, experiments are performed using the images of both dielectric and metal surfaces. Experimental results show that the presented approach outperforms the traditional methods from the point of view of sensitivity to correctness. View full abstract»

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  • Automatic foreground extraction via joint CRF and online learning

    Publication Year: 2013 , Page(s): 1140 - 1142
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (107 KB)  

    A novel approach is proposed for automatic foreground extraction which aims to segment out all foreground objects from the background in the image. The segmentation problem is formulated as an iterative energy minimisation of the conditional random field (CRF), which can be efficiently optimised by graph-cuts. The energy minimisation is initialised and modulated by a soft location map predicted by a discriminative classifier which is learned on-the-fly from a set of segmented exemplar images. Iteratively minimising the CRF energy leads to optimal segmentation. Experimental results on the Pascal visual object classes (VOC) 2010 segmentation dataset, a widely acknowledged difficult dataset, show that the proposed approach outperforms the state-of-the-art techniques. View full abstract»

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  • Design of integer motion estimator of HEVC for asymmetric motion-partitioning mode and 4K-UHD

    Publication Year: 2013 , Page(s): 1142 - 1143
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (259 KB)  

    A design for an integer motion estimator of high-efficiency video coding (HEVC) is presented. HEVC supports the 64 × 64 coding tree unit, the recursive quad-tree coding unit structure and the asymmetric motion-partitioning mode in a high compression ratio. These features require a structure of integer motion estimation that is more complex than that of H.264/AVC. The new structures of a memory read controller and a sum of absolute difference (SAD) summation block are proposed. The new memory read controller reduces the internal memory read time, and the new SAD summation block structure supports the recursive quad-tree coding unit structure and the asymmetric motion-partitioning mode. The proposed design is implemented in Verilog HDL and synthesised using the 65 nm CMOS technology. The gate count is 3.56 M, and the internal static random access memory is about 20 kbyte. The operation frequency is 250 MHz when a 4 K-Ultra high definition (UHD) (3840 × 2160P at 30 Hz) sized video is encoded. View full abstract»

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  • Efficient foreground detection for real-time surveillance applications

    Publication Year: 2013 , Page(s): 1143 - 1145
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (148 KB)  

    The problem of foreground detection in real-time video surveillance applications is addressed. Proposes is a framework, which is computationally cheap and has low memory requirements. It combines two simple processing blocks, both of which are essentially background subtraction algorithms. The main novelty of the approach is a combination of an autoregressive moving average filter with two background models having different adaptation speeds. The first model, having a lower adaptation speed, models long-term background and detects foreground objects by finding areas in the current frame which significantly differ from the proposed background model. The second model, with a higher adaptation speed, models the short-term background and is responsible for finding regions in the scene with a high foreground object activity. The final foreground detection is built by combining the outputs from these building blocks. The foreground obtained by the long-term modelling block is verified by the output of the short-term modelling block, i.e. only the objects exhibiting significant motion are detected as real foreground objects. The proposed method results in a very good foreground detection performance at a low computational cost. View full abstract»

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  • High-throughput CABAC codec architecture for HEVC

    Publication Year: 2013 , Page(s): 1145 - 1147
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (285 KB)  

    A VLSI architecture of a context adaptive binary arithmetic coding (CABAC) entropy codec for high-efficiency video coding (HEVC), the next generation video coding standard, is presented and analysis of its performance in terms of effective processing throughput, i.e. bin/s, is provided. For high throughput, the architecture is designed to process up to two regular bins per unit time while minimising pipeline stall due to inherent dependencies of CABAC through various optimisations including context forwarding and speculative decoding. The experiments show that the effective throughput is achieved up to 1.60 bins or 1.41 bits per cycle, which corresponds to 469.5 Mbit/s at the operating frequency of 333 MHz, under practical video coding environments. View full abstract»

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  • Parametric estimation of structural similarity degradation for video transmission over error-prone networks

    Publication Year: 2013 , Page(s): 1147 - 1148
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (236 KB)  

    A parametric model to estimate the degradation of objective video quality over error-prone networks is proposed. The model estimates an expected quality degradation in terms of one of the most reliable perceptual quality metrics, structural similarities (SSIMs), for a given encoded video and network condition described by a packet loss rate. The simulation results demonstrate that the proposed model can estimate the expected SSIM degradation of H.264/ advanced video coding encoded videos with high accuracy. View full abstract»

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  • Combination of step sizes for affine projection algorithm with variable mixing parameter

    Publication Year: 2013 , Page(s): 1149 - 1150
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (475 KB)  

    An algorithm that introduces a novel scheme for the combination of the two adaptation terms of the affine projection algorithm with different step sizes is proposed. The mixing parameter of the proposed algorithm is determined by minimising the mean-square deviation. The simulation results show that the proposed algorithm has a faster convergence rate and a smaller steady-state error than other existing combination algorithms. View full abstract»

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  • Combined one-dimensional lowpass and highpass filters for subband transformer

    Publication Year: 2013 , Page(s): 1150 - 1152
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (365 KB)  

    Subband transformation coefficients are typically computed by first filtering and downsampling of an input uncompressed signal and then subsequently filtering and downsampling the result intermediate signals with a set of lowpass and highpass filters. State-of-the-art subband transformers are complex, which increases consumed power. A novel method for significantly decreasing the complexity of subband transformers to a minimum is presented. This solution was implemented in a field programmable gate array, together with various methods for compression and decompression. View full abstract»

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Aims & Scope

Electronics Letters is internationally renowned for its rapid communication of new developments and emerging topics across the broad and interdisciplinary field of modern electronics and electrical engineering.

Full Aims & Scope

Meet Our Editors

Editors-in-Chief

Professor Chris Toumazou
Director of the Biomedical Institute
Imperial College, London, UK

Professor Ian White
Head of Photonics Research
University of Cambridge, UK