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Electronics Letters

Issue 2 • Date January 2011

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Displaying Results 1 - 25 of 57
  • In brief

    Page(s): 68
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  • Interview

    Page(s): 68
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  • Antennas see the light

    Page(s): 69
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (447 KB)  

    Researchers in Ireland have designed and built a 3.5 GHz solar antenna that is cheaper and simpler to manufacture than previous designs. By integrating an optically transparent patch antenna with an amorphous silicon solar module, the team from the Dublin Institute of Technology have created a solar antenna suitable for wireless and sensor network applications that has a reduced area footprint, and can be assembled after solar module manufacture. View full abstract»

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  • A small-scale approach to PDM

    Page(s): 70
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (358 KB)  

    Nanoantennas that could simplify polarisation division multiplexing (PDM) systems have been demonstrated by researchers at Universidad Autónoma de San Luis Potosí. J. Simón and F.J. González have fabricated a dipole nanoantenna which shows good polarisation discrimination to two orthogonal linear polarisations, and could be used to replace the conventional semiconductor detectors commonly used in optical communication systems. View full abstract»

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  • Efficient μ-law improved proportionate affine projection algorithm for echo cancellation

    Page(s): 73 - 74
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    For echo cancellation, the proportionate affine projection algorithm (APA) has been proposed to take advantage of the sparseness of the echo path. In this reported work, the μ-law proportionate technique is applied to the APA combined with a recently proposed structure having a memory of the proportionate step-size control matrices. Simulation results show that this new algorithm, termed the μ-law memorised improved proportionate APA (MMIPAPA), as well as its segmented implementation (SMIPAPA), yields a further performance improvement while maintaining low computational complexity. View full abstract»

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  • Extracting a source of shorter source-to-microphone distance from convolutive mixtures

    Page(s): 74 - 76
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (66 KB)  

    Although blind source extraction is advantageous over blind signal separation in practical applications, it is difficult to choose the extracted source from many sources in the mixtures. A new algorithm is presented to extract a source signal of shorter source-to-microphone distance from two convolutive mixtures. The developed algorithm imposes an additional constraint on the extracting filters, i.e. high direct-to-reverberation ratio. In experiments, the algorithm successfully extracted the shorter-distance signal even though the interference was much stronger for both simulated convolutive mixtures and real-recorded mixtures in an office room. View full abstract»

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  • Broadband waveguide slot array for SAR

    Page(s): 76 - 77
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (182 KB)  

    A new kind of wideband waveguide slot array for synthetic aperture radar (SAR) is presented. Elliptical slots are first used for designing the waveguide slot antenna. An eight-element waveguide slot array operating at X-band is designed and measured. Predicted results are compared with measured data and good agreement is reported. The measured bandwidth for VSWR ≤ 1.5 has reached 19.6%. View full abstract»

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  • Aperture UWB antenna with triple band-notched characteristics

    Page(s): 77 - 79
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (275 KB)  

    A novel semi-circle-shaped aperture ultra-wideband (UWB) antenna with triple band-notched characteristics is proposed. The band notches are realised by etching one complementary split-ring resonator inside a circular exciting stub on the front side, employing a interrogation-shaped defected ground structure in each side of the ground plane as well as symmetrically adding a pair of open-circuit stubs at the edge of the slot, and tri-band rejected filtering properties in the WiMAX/WLAN are achieved. Experimental results show that the designed antenna, with compact size of 24 × 30 × mm2, has an impedance bandwidth of 2.6 - 12 - GHz for VSWR less than 2, except three freqency stop-bands of 3.3 - 4, 5.15 - 5.4, and 5.8 - 6.1 - GHz. Moreover, the antenna has good omnidirectional radiation patterns in the H-plane. View full abstract»

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  • Compact integrated monopole antenna with CPW-fed meander resonators

    Page(s): 79 - 80
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (209 KB)  

    A monopole antenna integrated with various coplanar waveguide (CPW)-fed meander resonators is presented. A CPW-fed meander resonator combined with a folded one is integrated into a single monopole to produce a multiband antenna in the applications of global system for mobile communication (GSM), global positioning system, personal communication systems and wireless code division multiple access (WCDMA) services. The antenna has exhibited impedance bandwidths from 50 MHz at GSM to 370 MHz at WCDMA less than 10 dB of S11. The antenna gains are -5.8, -3.8, -0.6-dBi at 880, 1570, 2100-MHz, respectively. View full abstract»

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  • Experimental realisation of integrated THz electromagnetic crystals (EMXT) H-plane horn antenna

    Page(s): 80 - 82
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (272 KB)  

    An integrated terahertz (THz) H-plane horn antenna made of an electromagnetic crystals (EMXT) straight waveguide feed and a gradually flared horn is investigated. The EMXT structure is composed of metallised periodic square rods with dimensions of 48×48×241××m (width×length×height). The THz horn antenna is simulated using the finite element method and fabricated by microelectromechanical systems technology on silicon substrate. Measured attenuation loss of the EMXT straight waveguide is 0.17×dB per wavelength at 0.5×THz (××600××m). Good radiation patterns with 25× half power beam width and a low sidelobe of ×18.2×dB in the H-plane are demonstrated at 0.5×THz. View full abstract»

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  • Miniaturised integrated antenna set for RFID/UWB applications

    Page(s): 82 - 83
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (269 KB)  

    Described is a high-efficiency miniaturised antenna set including one scavenging antenna at 5.8 GHz and one UWB antenna at 5.5 GHz with at least 500 MHz bandwidth. This antenna set is integrated with a same wireless-powered RFID chip in 5.8 GHz. The proposed antennas are derived from a new planar antenna structure which can be designed towards any arbitrary input impedance within a given area constraint. Measurement results concerning read range and realised gain for the proposed antenna are presented and compared with simulation results, showing good agreement. View full abstract»

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  • Reflectarray element using interdigital gap loading structure

    Page(s): 83 - 85
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (210 KB)  

    A novel reflectarray element using an interdigital gap loading structure is proposed. A wide reflection phase range of more than 1000° is obtained, which can support a sufficient phase range for a large scattering angle (up to 60°) reflectarray. Furthermore, this element has a feature of equal element size because the reflection phase is adjusted by controlling the finger length of the interdigital gap. Thus, abrupt geometry variations for consecutive cells in the traditional reflectarray can be avoided. A Ku-band reflectarray has been fabricated and measured results show good agreement with simulation. View full abstract»

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  • Transparent patch antenna on a-Si thin-film glass solar module

    Page(s): 85 - 86
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (192 KB)  

    An optically transparent microstrip patch mounted on the surface of a commercially available solar module is proposed. The patch comprises a thin sheet of clear polyester with a conductive coating. The amorphous silicon solar cells in the module are used as both a photovoltaic generator and the antenna ground plane. The proposed structure provides a peak gain of 3.96 dBi in the 3.4-3.8 GHz range without significantly compromising the light transmission in the module. A comparison between copper and transparent conductors is made in terms of antenna and solar performance. The proposed technique is considerably simpler than previous integration approaches. View full abstract»

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  • Tri-band circularly-polarised antenna for CERTO application

    Page(s): 86 - 87
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (218 KB)  

    A novel tri-band circularly-polarised antenna for coherent electromagnetic radio tomography (CERTO) application is proposed. Based on the traditional crossed-dipole and the theory of transmission line, the antenna was designed for tri-band frequencies operation. Good radiation patterns and axial ratio are presented. View full abstract»

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  • Improved ECG compression method using discrete cosine transform

    Page(s): 87 - 89
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (113 KB)  

    An improvement of a discrete cosine transform (DCT)-based method for electrocardiogram (ECG) compression is presented. The appropriate use of a block based DCT associated to a uniform scalar dead zone quantiser and arithmetic coding show very good results, confirming that the proposed strategy exhibits competitive performances compared with the most popular compressors used for ECG compression. View full abstract»

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  • Time-sharing bilinear delay interpolation for ultrasound dynamic receive beamformer

    Page(s): 89 - 91
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (142 KB)  

    In ultrasound dynamic receive beamforming, focusing delays need to be updated for individual focal points, leading to increased hardware complexity. Proposed is a new efficient delay calculation method based on time-sharing bilinear delay interpolation (TS-BDI) to reduce both hardware complexity and focusing delay errors for portable ultrasound systems. The TS-BDI provides 2.5 dB improvement in the signal-to-noise ratio compared to the TS-LDI (linear delay interpolation). In addition, the proposed TS-BDI lowers the hardware complexity in the 64-channel digital dynamic receive beamformer compared to the conventional method, i.e. 36.0 reduction in equivalent gate counts. These results indicate that the proposed TS-BDI method could provide better accuracy in focusing delay calculation with reduced hardware complexity for portable ultrasound systems. View full abstract»

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  • Correlated level shifting integrator with reduced sensitivity to amplifier gain

    Page(s): 91 - 92
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    An integrator that achieves gain enhancement by utilising correlated level shifting is proposed. The integrator realisation avoids the use of an extra settling phase usually required in correlated level shifting. The superior performance of the proposed integrator compared to the conventional integrator is shown via simulation results. View full abstract»

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  • Mixed-mode QPSK demodulator for home networking applications

    Page(s): 92 - 94
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (343 KB)  

    A mixed-mode QPSK demodulator for home networking application is demonstrated. The target application is high-bandwidth data transmission through the CATV line at home. A prototype chip realised by a 0.18 m CMOS process can demodulate 1 Gbit/s QPSK data with 1.7 GHz carrier frequency in a 20 m CATV line link. It consumes 20.8 mW from an 1.8 V power supply while the area is 170 × 200 μm2. View full abstract»

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  • Capturing skin effect with an effective nonuniform mesh and coupled R-L circuits

    Page(s): 94 - 95
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (319 KB)  

    The frequency dependent inductances and resistances due to skin effect result in inaccurate solutions for electrical interconnect and package design and electromagnetic compatibility modelling. A novel nonuniform mesh approach for rectangular conductors and the calculation of resultant skin effect equivalent circuit elements are proposed. With this procedure, skin effect is effectively characterised by a parallel coupled R-L circuit network with a few elements. View full abstract»

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  • Compensation of electric cross-field response in shielded loop probe

    Page(s): 95 - 97
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (228 KB)  

    The singly-loaded shielded loop probe is investigated with respect to its sensitivity to electric fields. A standing-wave open microstrip transmission line cell is used to measure the response of a loop probe of 1% wavelength diameter to the magnetic field normal to the loop plane and to the electric field along its symmetry axis and along its cross direction. The response to the electric cross-field is shown to exhibit the characteristic of a short electric dipole, which has inspired a compensation technique using an additional wire dipole cross-connected over the shield gap. Experimental results of the compensation technique are presented, which show effective reduction of the E-field pick-up by 10-15 dB while maintaining the useful properties of the H-field probe. View full abstract»

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  • Generic framework for content-based stereo image/video retrieval

    Page(s): 97 - 98
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (104 KB)  

    With the increasing number of stereo images/videos in commercial markets, the demand for content-based image retrieval (CBIR) to deal with stereo media becomes urgent. To meet this demand, a novel framework is proposed where depth cues are extracted from stereo pairs and employed in a re-ranking scheme to refine results from conventional CBIR. Experiments show the proposed method yields promising results in retrieving stereo content. View full abstract»

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  • Method for fingerprint orientation field reconstruction from minutia template

    Page(s): 98 - 100
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (189 KB)  

    Recent progress in fingerprint reconstruction has shown that most of the fingerprint information can be restored using only the minutia set. During the reconstruction procedures, orientation field reconstruction is a critical step. Proposed is a Gaussian weighted method for fingerprint orientation field reconstruction from the minutia template only. In the method, prior information about ridge flow characteristics is considered to more accurately model the ridge orientation. Experimental results show that our method can obtain an accurate orientation field in terms of the accuracy of the orientation field based fingerprint classification and the performance of the orientation descriptor based fingerprint matching. View full abstract»

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  • Colour image retrieval using pattern co-occurrence matrices based on BTC and VQ

    Page(s): 100 - 101
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (98 KB)  

    Proposed is an effective feature for colour image retrieval based on block truncation coding (BTC) and vector quantisation (VQ). Each input colour image is decomposed into Y, Cb and Cr components. BTC is performed on the 4×4 Y blocks, obtaining a mean pair sequence and a bitplane sequence, and then they are quantised with the contrast pattern codebook and visual pattern codebook to obtain the contrast and visual pattern co-occurrence matrix. VQ is performed on the 4×4 Cb blocks and Cr blocks with the Cb codebook and Cr codebook, respectively, to obtain the colour pattern co-occurrence matrix. Retrieval simulation results show that, compared with two existing BTC-based features, the proposed feature can greatly improve retrieval performance. View full abstract»

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  • Efficient polygonal posture representation and action recognition

    Page(s): 101 - 103
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (159 KB)  

    An approach to human action modelling and recognition in continuous action sequences is proposed. A star figure enclosed by a bounding convex polygon is used to effectively represent the extremities of the silhouette of a human body. Thus, human actions are recorded as a sequence of the star figure's parameters, which is then used for action modelling. To model human actions in a compact manner while characterising their spatiotemporal patterns, star figure parameters are represented by a 2D feature map, which is used and regarded as a spatiotemporal template. Experiments to evaluate the performance of the proposed framework show that it can recognise human actions in an efficient and effective manner. View full abstract»

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  • Limitations of multiple reference frames with cyclic intra-refresh line for H.264/AVC

    Page(s): 103 - 104
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (95 KB)  

    In multiple reference frame coding the compression efficiency of the codec improves with increasing the number of reference frames. However, it is shown that when cyclic intra-refresh lines are used to prevent error propagation, increasing the number of reference frames reduces the received video quality in the presence of transmission errors. 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