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Electronics Letters

Issue 25 • Date December 9 2010

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Displaying Results 1 - 25 of 46
  • In Brief

    Publication Year: 2010 , Page(s): 1638
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  • A self-scan system

    Publication Year: 2010 , Page(s): 1638
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  • Inside View

    Publication Year: 2010 , Page(s): 1639 - 1640
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    The world's first antenna that mimics the hearing mechanism of insects has been unveiled by researchers at the University of Wisconsin in the US. Dr Nader Behdad tells us more. View full abstract»

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  • Interview

    Publication Year: 2010 , Page(s): 1640
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    Dr Benoit Charbonnier from France T??l??com talks about his research and the motivations for the development of the `Refl ective polarisation independent Mach- Zehnder modulator for FDMA/ OFDMA PON?? presented on page 1682. View full abstract»

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  • Coaxial-to-waveguide adapter generating circularly polarised wave

    Publication Year: 2010 , Page(s): 1643 - 1644
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (394 KB)  

    A technique of generating a circularly polarised wave by reflection type is presented using a coaxial-to-waveguide adapter. The adapter consists of a polarisation twisting section and a phase-delay section for the generation of circular polarisation in the circular waveguide. The design and the implementation of the adapter demonstrate the advantage of significant size reduction and the possibility to overcome the weight concern problems in waveguide systems. View full abstract»

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  • Compact printed antenna with 𝒽-shaped stub for dual-band operation

    Publication Year: 2010 , Page(s): 1644 - 1645
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (430 KB)  

    A novel compact printed antenna design with a h-shaped stub for dual-band operation is presented. The proposed antenna is simply composed of a h-shaped stub resonator and a monopole radiator. The special asymmetry h-shaped stub extended from the ground can achieve a new resonance as well as reduced antenna size. Based on this concept, a prototype of the dual-band antenna has been designed, fabricated and tested. Experimental results show the antenna covers 2.36-2.58 and 4.53-6.38-GHz with 10-dB return loss, covering the desired bandwidths of WLAN and C-band applications. View full abstract»

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  • Experimental detection of Brillouin precursors through tap water at microwave frequencies

    Publication Year: 2010 , Page(s): 1645 - 1647
    Cited by:  Papers (15)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (239 KB)  

    Proposed is a simple technique to analyse Brillouin precursor waveforms propagating through a dispersive medium at microwave frequencies. The technique has been successfully used in modelling these precursors through 10 cm deep normal tap water using the experimental S-parameter data collected with a vector network analyser from 100 MHz to 2.5 GHz. The proposed technique is general enough to be applied on pulses of any type and shape and at any carrier frequency, within the constraints given by the bandwidth covered during the measurement stage. The pulse under consideration can be reconstructed using the software algorithms applied on the measured data, thereby simplifying the hardware needed to conduct the experiments. View full abstract»

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  • Frequency invariant power pattern synthesis for arbitrary arrays via simulated annealing

    Publication Year: 2010 , Page(s): 1647 - 1648
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (216 KB)  

    A frequency invariant power pattern is synthesised, based on the weighted least-squares criterion. An auxiliary function is introduced to transform the nonlinear synthesis problem into a linear one. The phases of the desired pattern are calculated by the simulated annealing technique, and the weighting function is iteratively modified to achieve a desired power pattern. View full abstract»

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  • Frequency reconfigurable log periodic patch array

    Publication Year: 2010 , Page(s): 1648 - 1650
    Cited by:  Papers (4)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (308 KB)  

    A novel reconfigurable low profile log periodic patch array is presented. The patches are fed with a modulated meander line through aperture slots. A wideband mode from 7-10-GHz and three selected narrow band modes at 7.1, 8.2, and 9.4-GHz are demonstrated. The wideband to narrow band reconfiguration is realised by bridging the slot aperture, effectively deactivating the corresponding radiating element. Potentially the proposed method offers a very fine control of a narrow passband. Measured and simulated results with very good agreement are presented, thus verifying the proposed concept. View full abstract»

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  • Biomimetic electrically small antennas

    Publication Year: 2010 , Page(s): 1650 - 1651
    Cited by:  Papers (10)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (187 KB)  

    Many insects possess acute directional hearing capabilities and are able to localise a sound source of interest with a good degree of precision. An analogy can be drawn between the hearing mechanisms of such insects and a two-element, electrically small antenna array. Presented is a biomimetic electrically small antenna array that mimics the hearing mechanism of an insect with hyperacute directional hearing capability. A prototype of such an antenna has been fabricated and its simulated and measured results are presented. Such biomimetic antenna arrays could be used in numerous applications ranging from miniaturised RF sensors and direction finding systems to small aperture, high-resolution microwave imaging systems and radars. View full abstract»

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  • Development of portable breast self-examination device using enhanced tactile feedback

    Publication Year: 2010 , Page(s): 1651 - 1653
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (232 KB)  

    A simple tactile imaging system for detecting possible breast lumps is proposed. The breast cancer detection system (BCDS) consists of a palm-sized, portable, wireless scanning probe with a nine-force sensor array, a web camera, and a PC program to display the location and stiffness of hard breast lesions based on tactile pressure profiles. The results of performance evaluation tests using various breast phantoms demonstrated that palpable abnormalities larger than 5 mm located at depths less than 25 mm can be detected accurately. It is expected that this low-priced BCDS will extensively benefit all adults and ubiquitous healthcare services who apply regular breast self-examination by providing remote magnified palpation with enhanced tactile sensitivity. View full abstract»

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  • Dynamic frequency tracking and phase error compensation clock de-skew buffer

    Publication Year: 2010 , Page(s): 1653 - 1655
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (477 KB)  

    Proposed is a dynamic frequency tracking and phase error compensation clock de-skew buffer (CDSB) to reduce the clock skew between the input and output clocks of a chip. The proposed CDSB tracks the dynamic frequency in two clock cycles. Also, the CDSB utilises a fine tune circuit which is based on a cyclic rotation algorithm to compensate for the dynamic phase error. Measured results show that the operating frequencies of the CDSB are from 200 to 450 MHz. Also, the CDSB tracks the dynamic frequency in two clock cycles. The power consumption, RMS jitter, and peak-to-peak jitter of the CDSB are 9.71 mW, 2.7 ps, and 31.3 ps at 450 MHz. View full abstract»

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  • Continuous time ΣΔ modulator based on digital delay loop and time quantisation

    Publication Year: 2010 , Page(s): 1655 - 1656
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (184 KB)  

    A new sigma delta (ΣΔ) modulator suitable for ultra-low power data converters is introduced. The proposed architecture is based on time encoding and quantisation using voltage controlled delays such as digital inverters. The delays together with a phase comparator implement a synchronous pulse width modulator (PWM) and a discrete time integrator. An additional analogue integrator provides second-order noise shaping and compensates the nonlinearity of the digital delay. Time quantisation of the two-level PWM signal allows implementing a multibit modulator without requiring linear multibit DACs. View full abstract»

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  • Data reduction method of sine look-up tables in microprocessor's memory storage

    Publication Year: 2010 , Page(s): 1656 - 1658
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (237 KB)  

    A data reduction method of sine look-up tables for low-end microprocessors which have small memory capacity and low process speed is proposed. The proposed method is composed of an encoded sine look-up table (LUT), a linear interpolation technique, and an effective decoding algorithm. The data reduction method minimises the usage of the memory capacity for the sine LUT. It can support low-end microprocessor applications such as single-phase inverter, UPS, direct digital frequency synthesis, etc. View full abstract»

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  • High fill factor CMOS APS sensor with extended output range

    Publication Year: 2010 , Page(s): 1658 - 1659
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (198 KB)  

    A new active pixel sensor (APS) circuit architecture with increased signal range is proposed. This feature contributes to improvement of the dynamic range of the imager, since it is effectively a way to increase the full well capacity, which is reduced as pixel pitch decreases. The proposed solution does not degrade the fill factor, and can be applied to most existing CMOS APS pixels. The new readout topology is described and experimental results for a 64 × 64 3T photodiode pixel array are given. View full abstract»

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  • Integrated approach towards adaptive state-tracking job migration for maximising performance benefit

    Publication Year: 2010 , Page(s): 1659 - 1661
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (216 KB)  

    Presented is a new state-tracking migration policy which is adaptively integrated with immediate restart and selective preemption techniques for risk-resilient job allocation in high-throughput computing environments. The proposed approach guarantees the maximum reduction of inevitable delays with relatively low migration costs. Simulation results show that the integrated migration policy averagely outperforms the conventional mechanisms by 26% in makespan and 33% in throughput, respectively, under various job%s burstiness. View full abstract»

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  • Recursive wideband digital differentiators

    Publication Year: 2010 , Page(s): 1661 - 1662
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (303 KB)  

    Novel designs of recursive wideband digital differentiators are presented. These designs are obtained by the optimisation of magnitude response and the analysis of pole-zero plot. The beauty of these designs is that they are only of second order and have not more than 2% relative error in magnitude responses over wideband with different phase responses, thus being suitable for real-time applications. View full abstract»

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  • Radiator heightens power density of piezoelectric transformers

    Publication Year: 2010 , Page(s): 1662 - 1663
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (241 KB)  

    A new method to heighten the power density of piezoelectric transformers based on heat transfer is presented. The common grounded surface of a piezoelectric plate transformer was closely contacted to an extra smooth copper surface through which the heat can be well dissipated by an aluminium radiator. Although the contact interface may produce additional friction heat, the experimental results show that the mechanism gives excellent performance. The prototype transformer could maintain a power density of 135 W/cm3 with an efficiency of 90.8% for a long working time. View full abstract»

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  • Fast mode decision algorithm for spatial scalable video coding

    Publication Year: 2010 , Page(s): 1663 - 1665
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (124 KB)  

    Multimedia applications are ubiquitous in daily life. To satisfy multiple requests equipped with different devices and bandwidths, scalable video coding has been developed. However, it is difficult to realise spatial and quality scalabilities in practice owing to the increased coding complexity brought by inter-layer prediction. A novel fast mode decision algorithm for spatial scalable video coding is proposed in which macroblock modes in the base layer and the enhancement layer are predicted from each other. The experimental results show that the proposed algorithm provides up to 74% of time saving with ignorable quality degradation and acceptable bit rate increase. View full abstract»

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  • Bias reduction for stereo triangulation

    Publication Year: 2010 , Page(s): 1665 - 1666
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (134 KB)  

    Stereo triangulation lays at the basis of 3D scene recovery and it is used in a wide variety of areas ranging from urban modelling to robot localisation and mapping. However, triangulation produces non-Gaussian 3D estimates from Gaussian image measurements owing to its nonlinear nature. While previous work demonstrates the presence of statistical bias and how to correct the depth estimate, in this presented report, proposed and proven in a Monte Carlo test, is an enhancement for correcting the full 3D position given the image projection noise variance. View full abstract»

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  • Ore image thresholding using bi-neighbourhood Otsu's approach

    Publication Year: 2010 , Page(s): 1666 - 1668
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (223 KB)  

    A new thresholding algorithm based on two neighbourhoods and Otsu's method is proposed. For each pixel, its two neighbourhoods are chosen by image and object sizes. The thresholds of neighbourhoods are optimised by Otsu's method, and then every pixel is binarised through the minimum of thresholds. Experimental results show that the proposed algorithm improves thresholding performance efficiently, especially for multi-object and uneven lighting images. View full abstract»

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  • Scaled zero coefficient-aware IDCT algorithm for fast video decoding

    Publication Year: 2010 , Page(s): 1668 - 1669
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (63 KB)  

    Proposed is a scaled zero coefficient-aware fast inverse discrete cosine transform (IDCT) algorithm that substantially outperforms the existing fixed-point 8×8 IDCT standard. The concept of the fixed-point approximation with accurate dyadic terms is applied to the zero coefficient-aware IDCT algorithm, improving the computational complexity of the authors× previous work. The experimental results show that the running time of the proposed scaled zero coefficient-ware algorithm is faster than that of the fixed-point 8×8 IDCT standard by a speed-up factor of 2.0 times on average and up to 2.6 times for the HD sequences. View full abstract»

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  • Copulas of bivariate Rayleigh and log-normal distributions

    Publication Year: 2010 , Page(s): 1669 - 1671
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (195 KB)  

    The intrinsic relations between multivariate distributions and their marginal distributions can be clearly characterised by copulas. The bivariate Rayleigh and bivariate log-normal distributions play important roles in both signal processing and digital communications. In this reported work, the formula of bivariate Rayleigh copula is improved and the formula of bivariate log-normal copula is derived. These formulas are in terms of the Marcum Q-function or the Gaussian Q-function, both being supported by Matlab. Thus the copula evaluation process can be expedited both analytically and numerically. View full abstract»

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  • Higher-order multi-interval line coding

    Publication Year: 2010 , Page(s): 1671 - 1673
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (156 KB)  

    Multi-interval line coding (MILC) is considered with higher-order signalling. A simple recursive method to calculate the maximum number of valid MILC waveforms for any order of signalling is presented. Following the introduced recursive method, attractive higher-order MILC schemes are found. Properties of 3-ary and 4-ary MILC schemes are listed. MILC schemes that can increase the data rate by 25-40- over known PAM signals are reported. View full abstract»

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  • Selecting optimal norm and step size of generalised constant modulus algorithms under non-stationary environments

    Publication Year: 2010 , Page(s): 1673 - 1674
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (138 KB)  

    A family of generalised constant modulus algorithms (GCMAs) based on the norm of complex variables was recently proposed. However, the optimal norm and step size of GCMAs have not been derived owing to the complexity of the proposed cost function. The steady-state mean square error (MSE) of a class of GCMAs under non-stationary environments is now given in a closed form. The optimal norm and step size can be derived to minimise the steady-state MSE with this closed form. Numerical simulations confirm the superior performance of the optimal norm and step size. 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