By Topic

Electronics Letters

Issue 11 • Date May 22 2014

Filter Results

Displaying Results 1 - 25 of 36
  • In brief

    Page(s): 780
    Save to Project icon | PDF file iconPDF (3076 KB)  
    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Interview

    Page(s): 780
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (2944 KB)  

    Dr Vit Sipal from the Antenna and High Frequency Research Centre at the Dublin Institute of Technology, on the work behind the paper `Using near-field coupled circularly polarised antennas as frequency independent variable phase-shifters??, V. Sipal, A. Narbudowicz and M.J. Ammann, Page 788. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Seeing through a mask

    Page(s): 781
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (3184 KB)  

    Low cost and complexity real-time THz imaging may be within reach as work in the US combines commercially available digital light processing technology and compressed sensing to enhance coded aperture imaging. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Inside view

    Page(s): 782
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (3253 KB)  

    Researchers at Stanford University talk about magneto-acoustic imaging, a technique that combines the strengths of existing medical imaging tools; improving safety and the potential for greater compactness and lower cost. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • CPW balun for printed balanced antennas

    Page(s): 785 - 786
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (414 KB)  

    In coplanar waveguide (CPW) circuits, printed balanced antennas must be excited through baluns. These baluns often feature coplanar-to-slotline transitions that must be tuned and matched by electromagnetic optimisation, and may interfere with the antenna backward radiation. A new CPW balun for printed balanced antennas is presented and modelled. As its multimodal circuit model makes clear, it integrates an impedance-matching network within its structure that can be analytically designed. The balun has been experimentally tested, exhibiting good agreement with its circuit model and a weak electromagnetic interaction with the antenna radiation. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Reconfigurable dual-port UWB diversity antenna with high port isolation

    Page(s): 786 - 788
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (595 KB)  

    A reconfigurable dual-port diversity antenna for ultra-wideband application is presented. The proposed design can be configured either in stacked/back-to-back arrangement by placing radiating elements facing in the opposite directions or in orthogonal arrangement. The proposed designs are realised on FR4 substrate of dimensions 40 × 36 × 1.5 mm. By introducing an efficient decoupling structure in the ground plane, both configurations maintain an isolation better than 25 dB over the complete band. Performance of the proposed design is verified by the measured results including s-parameters, envelope correlation coefficient, total active reflection coefficient and channel capacity loss. The proposed design is suitable for integration in three-dimensional (3D) system-in-package applications. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Using near-field coupled circularly polarised antennas as frequency-independent variable phase shifters

    Page(s): 788 - 790
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (529 KB)  

    A novel concept of frequency-independent variable phase shifters is introduced. It is based on the use of circularly polarised (CP) antennas coupled in the near-field. For transmission between two CP antennas in the far-field, a rotation around the boresight axis produces a phase change in the transfer function. This concept is exploited and validated also for near-field coupling between two CP antennas. Therefore, two close-coupled CP antennas can act as an adjustable phase shifter with the phase shift controlled by the angle between the structures. The bandwidth depends on the CP bandwidth of the antenna. This concept is valuable for future phase shifters in millimetre-wave applications where rotation can be facilitated by MEMS elements. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Frequency-modulated magneto-acoustic detection and imaging

    Page(s): 790 - 792
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (464 KB)  

    Magneto-acoustic (MA) tomography combines near-field RF and ultrasound for the goal of a safe, high-resolution, high-contrast bimodal imaging technique. Coherency between RF excitation and the resulting ultrasound generation through Lorentz force interactions is established. This allows for continuous-wave (CW) imaging techniques to replace conventional pulsed-based approaches, easing system design and improving signal-to-noise ratio (SNR) while reducing the peak-to-average excitation power ratio, for the same averaging time, sensitivity and gain. This is the first successful demonstration of MA detection using step frequency CW (SFCW) as well as frequency-modulated CW (FMCW) approaches with up to 36 dB SNR improvement. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • 1-5 GHz duty-cycle corrector circuit with wide correction range and high precision

    Page(s): 792 - 794
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (467 KB)  

    An all-analogue feedback duty-cycle corrector (DCC) circuit with high precision and frequency is presented to tighten duty cycle into an allowable range and compensate for duty-cycle uncertainties in high-speed interfaces. The proposed DCC is employed to calibrate the duty cycle of the clock to reduce the deterministic jitter introduced by the duty-cycle distortion. It extracts the duty-cycle information by a differential duty amplifier detection scheme and corrects the clock distortion by a duty-cycle adjuster through the negative feedback loop. The DCC has improved robustness, correction range and operating frequency as compared with other DCCs. With post-simulated results using 55 nm CMOS technology, the output duty cycle is corrected to 50 ± 0.1% over the input duty-cycle range of 20-80% for 1-5 GHz. It consumes 3.6 mW at 3 GHz using a 1.2 V supply voltage and occupies an area of only 0.00174 mm2. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Double-sampled wideband delta-sigma ADCs with shifted loop delays

    Page(s): 794 - 795
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (328 KB)  

    A novel double-sampled wideband delta-sigma modulator topology with shifted loop delays is proposed. Compared with the conventional double-sampled modulator, this analogue-to-digital converter (ADC) implements the inherent quantisation delay by shifting one loop delay from the last integrator to the quantiser, and it relaxes the critical timing for dynamic element matching (DEM) by shifting the loop delay from the first integrator to the feedback path. In addition, by inserting one more delay in the signal path, the proposed modulator retains the low-distortion property. To verify the effectiveness of the proposed topology, a second-order double-sampled delta-sigma modulator is analysed and simulated. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Low-cost fixed-width squarer by using probability-compensated circuit

    Page(s): 795 - 797
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (316 KB)  

    A simple and uniform compensated bias for a fixed-width squarer is proposed. By employing the expected value of truncation parts, truncation errors can be efficiently alleviated. The proposed squarer derives a simple compensated bias and achieves a small area. The results show that the proposed squarer achieves low-cost, high-accuracy performance and yields higher values than previous designs do, particularly regarding the value of accuracy divided by the area-delay product. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Thermal sensitivity analysis of on-chip interconnects

    Page(s): 797 - 799
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (286 KB)  

    A new method for time-domain sensitivity analysis of on-chip coupled interconnects with non-uniform substrate temperature profiles is presented. The parametric macromodelling is performed via multivariate rational approximation using magnitude vector fitting algorithms. The waveform relaxation algorithm with transverse partitioning is employed for efficient sensitivity analysis of coupled interconnects. With these techniques, the thermal sensitivity of on-chip global interconnects arising from typical substrate thermal profiles are investigated. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Improved reliability properties of (Pb,La) (Zr,Ti)O3 ferroelectric capacitors by thin aluminium-doped zinc oxide buffer layer

    Page(s): 799 - 801
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (270 KB)  

    Chemical solution deposition (CSD)-derived ferroelectric PbLaZrTiOx (PLZT) capacitors with an aluminium-doped zinc oxide (AZO) top electrode is fabricated. The effects of a thin conductive AZO buffer layer between the Pt bottom electrode and PLZT were investigated. The hydrogen degradation resistance of PLZT capacitors with a 10 and a 20 nm AZO buffer layer was improved up to 91 and 81%, respectively, of an initial polarisation value even after 45 min annealing in a 3% hydrogen atmosphere, from 42% of that without a buffer layer. The fatigue endurance (at 200 kV/cm (10 V) at 100 μs pulse width at 1 ms intervals) of the PLZT capacitor with a 10 nm AZO buffer layer was also improved after 107 cycles. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Approaching real-time terahertz imaging with photo-induced coded apertures and compressed sensing

    Page(s): 801 - 803
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (262 KB)  

    Photo-induced coded-aperture imaging (PI-CAI) based on compressed sensing (CS) at 590 GHz using a WR-1.5 (500-750 GHz) vector network analyser is demonstrated. For a 256-pixel (16 × 16) frame, the acquisition time can be reduced by 40%, as compared with PI-CAI without CS, while maintaining high imaging quality. On the basis of this approach, it is envisioned that real-time (26 fps) THz imaging with 1000 pixels (32 × 32) can be realised using high-speed digital micromirror device chipsets and optimised data-acquisition software. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Coordinate logic order statistics filters: new approach for real-time image processing

    Page(s): 803 - 804
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (325 KB)  

    A new approach regarding real-time low-level image and signal processing is presented. This new approach deals with the philosophy of finding a method for designing and executing algorithms (filters), using the most minimum possible complexity. The proposed method is based on a special formation of coordinate logic filters (CLFs), the coordinate logic order statistics (CL-OS) filters. CL-OS introduces a minimalistic approach in filter design followed by the greatest possible efficiency in terms of speed, quality, complexity and energy consumption. Moreover CL-OS reveals new signal information; this information gives a different interpretation of the original signal, it could be said that it acts like a function applying a nonlinear quantisation in order to approximate the desired output. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Efficient parallel HEVC intra-prediction on many-core processor

    Page(s): 805 - 806
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (253 KB)  

    High-efficiency video coding (HEVC) is the state-of-the-art video coding standard, which adopts more complicated and time-consuming intra-prediction (IP) modes. Many-core processors are good candidates for speeding up HEVC IP in the case that HEVC IP can provide sufficient parallelism. Proposed is an efficient parallel framework for HEVC IP. Experiments show that the proposed method dramatically accelerates more than the state-of-the-art parallel method. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Is Hamming distance only way for matching binary image feature descriptors?

    Page(s): 806 - 808
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (413 KB)  

    Brute force matching of binary image feature descriptors is conventionally performed using the Hamming distance. The use of alternative metrics is assessed in order to see whether they can produce feature correspondences that yield more accurate homography matrices. Two statistical tests, namely analysis of variance (ANOVA) and McNemar's test were employed for the evaluation. Results show that Jackard-Needham and Dice metrics can display better performance for some descriptors. Yet, these performance differences were not found to be statistically significant. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Spiral symmetry centroid detection

    Page(s): 808 - 810
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (589 KB)  

    Radial symmetry detection is a hot topic in computer vision owing to its importance in understanding the image structure and content. A major generalisation to the problem is presented and single image spiral symmetric centroid detection is studied. Since radial symmetry is just a particular case in the model of spiral symmetry, spiral symmetry detection is more challenging and general. For this new problem, a fast and effective voting-based solution is proposed, which can reliably detect both the classical radial symmetric centre and the more general spiral symmetric centroid. Extensive experiments validate the generality and practicability of the proposed approach. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Simultaneous correlation architecture for multilevel complementary sequences

    Page(s): 810 - 812
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (219 KB)  

    Complementary sequences are being widely used in applications ranging from communication to radar and sonar systems. The properties of these sequences render them suitable for applications requiring signal detection in noisy environments and/or multi-user systems. The use of complementary sequences in practical applications with reduced hardware resources has promoted the development of efficient architectures that reduce the computational requirements for the generation and correlation of the sequences. An optimised architecture for the simultaneous correlation of pairs of multilevel complementary sequences is presented, which achieves that reduction by removing redundant operations. The proposal has an impact also on the correlation of binary complementary pairs of sequences of lengths of a power of 10 and 26 that use the multilevel architecture to generate the kernels. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • 2.8 dB conversion gain broadband HBT-HEMT balanced frequency tripler with high harmonic suppression

    Page(s): 812 - 814
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (318 KB)  

    A 10.2-12.6 GHz balanced heterojunction bipolar transistor (HBT)-high electron mobility transistor (HEMT) frequency tripler is presented. A pair of common-base/common-emitter HBTs is used to generate in-phase and out-of-phase harmonics. Two bandpass filters are utilised as matching networks to enhance the harmonic suppression. A common-gate/common-source HEMT active balun is employed to combine the third harmonic in-phase and provide conversion gain. The proposed frequency tripler shows a conversion gain of 2.8 dB, a fractional bandwidth of 21.2% and a fundamental suppression higher than 47 dB. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Four-channel 60 GHz upconversion mixer with 14 dB gain and 2.5 dBm P1dB using transformer matching network

    Page(s): 814 - 815
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (492 KB)  

    A 60 GHz upconversion mixer is realised in a 65 nm LP CMOS. The mixer consists of a Gilbert cell, a LO buffer and a RF buffer. To enhance the bandwidth and reduce the area, the transformer impedance matching network is used. The measured results show that the mixer covers the IEEE 802.15.3c standard four channels, from 57 to 66 GHz. In each channel, the gain flatness is <;1.5 dB. In channel 2, the mixer achieves a gain of 14 dB and an output power 1 dB compression point of 2.5 dBm, while consuming 32 mW power drain from a 1 V supply. To the best of authors' knowledge, this is an advance in the state-of-the-art mixers. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Filtering power divider with good isolation performance

    Page(s): 815 - 817
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (322 KB)  

    A filtering power divider (PD) with good isolation performance is presented. The isolation performance is improved by introducing a distributed isolation network (DINW) to replace the conventional resistor isolation network. Moreover, the proposed DINW can be incorporated into a filter design to form a filtering PD. The filtering power divider was implemented at a centre frequency of 1 GHz with a fractional bandwidth of 56%, and the measured isolation is better than 23 dB across the entire operating band. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Contactless radio frequency probes for high-temperature characterisation of microwave integrated circuits

    Page(s): 817 - 819
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (367 KB)  

    The first ever demonstration of a viable contactless radio frequency (RF) probing technique at elevated temperatures is presented. The design utilises an inverted microstrip design for the probe, which is suspended over and placed in close proximity to the input/output microstrip lines of the device under test to couple signals in and out. To demonstrate the efficacy of the contactless RF probing technique, three example circuits, namely, a microstrip spurline bandstop filter, a microstrip pin diode series switch and a monolithic microwave integrated circuit amplifier mounted on a microstrip line were designed, fabricated and performance measured against temperature upto 200°C. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Parameter determination for transmission lines with double periodical capacitive loading

    Page(s): 819 - 821
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (356 KB)  

    A method to determine the capacitors that represent the periodical loads of transmission lines embedded between woven fibre substrate layers is presented. The resulting model allows an accurate modelling of the transmission characteristics of striplines presenting double resonances when operated at microwave frequencies. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Tunable 3D dielectric resonator using a thermoconductive VO2 material

    Page(s): 821 - 823
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (308 KB)  

    A temperature-based tunable dielectric resonator is presented showing a tunability of 20 MHz around 11.8 GHz when heated with a drop of the quality factor from 4000 to 286. The puck-shaped alumina resonator contains a thin sapphire sheet coated with VO2. An overview of the thermoconductive VO2 material used is presented. The design and simulations of the resonator are presented along with the fabricated structure and measurements. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

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