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Electronics Letters

Issue 3 • Date January 31 2008

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Displaying Results 1 - 25 of 58
  • Localisation of light in disordered lattices

    Publication Year: 2008 , Page(s): 165 - 168
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (159 KB)  

    A short review of the basic concepts underlying localisation of light through multiple scattering in disordered media is provided, in conjunction with the ideas related to the universal features occurring during transport of waves and Anderson localisation. Progress in the area is described, including the recent experimental observation of localisation in photonic lattices upon which random perturbations are superimposed, which has constituted the first observation of Anderson localisation in any perturbed periodic system. Subsequently, some of the new intriguing concepts in the field of localisation of light are discussed, among them the combination of nonlinearity and disorder, and their effects on waves transport. Finally, being somewhat speculative, future directions in the area and their potential impact on the basic understanding of the universal phenomena associated with transport of waves are suggested. View full abstract»

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  • Quantum dot based nanophotonics and nanoelectronics

    Publication Year: 2008 , Page(s): 168 - 171
    Cited by:  Papers (23)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (144 KB)  

    Invention of non-disruptive fabrication technologies for semiconductor quantum dots presented a dream for generations of semiconductor device engineers. Today such technologies exist. A wealth of completely novel devices and such with dramatically improved properties based either on a single/few or a large density of quantum dots appears. Among them are single q-bit emitters, nano-flash memories, ultrafast lasers and amplifiers enabling a wealth of advanced systems. View full abstract»

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  • Low-power high-speed current comparator design

    Publication Year: 2008 , Page(s): 171 - 172
    Cited by:  Papers (14)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (126 KB)  

    A new current comparator is proposed that is optimised for low power consumption whilst maintaining high speed. This novel comparator design offers a reduction in power consumption of over three orders of magnitude compared with other high-speed designs, and allows picoampere current decisions at kilohertz frequencies. Circuit simulations were performed in Cadence software for a standard 0.35 mum process. View full abstract»

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  • 3.5/5.5 Ghz dual band-notch ultra-wideband antenna

    Publication Year: 2008 , Page(s): 172 - 174
    Cited by:  Papers (19)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (190 KB)  

    A compact and simple design of a CPW-fed planar antenna for ultra- wideband application with dual band-notch characteristics is presented. The proposed antenna yields an impedance bandwidth of 3.1- 10.6 GHz with VSWR < 2, except the bandwidths of 3.3-3.9 GHz for WiMAX and 5-6 GHz for WLAN. The antenna is successfully simulated, designed, and measured, showing broadband matched impedance, stable gain and omnidirectional radiation patterns. View full abstract»

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  • Conformal four-beam antenna arrays with reduced sidelobes

    Publication Year: 2008 , Page(s): 174 - 175
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (162 KB)  

    Investigations on sidelobe reduction in multibeam conformal antenna arrays are presented. The recently presented concept of sidelobe reduction in planar multibeam antenna arrays in conjunction with the phase compensation technique has been applied for the design of reduced sidelobe multibeam conformal antenna arrays. Six- and eight-element antenna arrays fed by modified Butler matrices have been investigated and minimum radii have been found for which the sidelobe level is comparable to the respective planar multibeam arrays. A novel fully integrated six-element four-beam antenna array has been successfully designed in which sidelobes equal -14 dB for all four beams have been achieved. View full abstract»

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  • Design of planar RFID tag antenna for metallic objects

    Publication Year: 2008 , Page(s): 175 - 177
    Cited by:  Papers (24)  |  Patents (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (166 KB)  

    Proposed is a novel RFID tag antenna consisting of an inner spiral dipole, an outer bent dipole and a double T-matching network that is suitable for attaching to metallic objects. For low-cost fabrication, the antenna is printed on a single-layer substrate without a ground plane or shorting pins. The detailed design parameters of the antenna were optimised using the Pareto genetic algorithm so that the antenna would operate adequately both in fiee space and on metallic objects. The antenna was fabricated, based on the optimised design, and the performance in fiee space and on a metallic surface were measured. The half-power matching bandwidth (VSWR < 5.8) and the reading range of the antenna in fiee space were 7.6% and 2.8 m, while on a metallic surface the corresponding values were 0.8% and 1.8 m. For non-metallic surfaces (i.e. low dielectric targets, 2 < epsivr < 4), the antenna exhibited the reading range of 2-3 m. View full abstract»

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  • Genetic algorithm based inversion of neural networks applied to optimised design of UWB planar antennas

    Publication Year: 2008 , Page(s): 177 - 179
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (89 KB)  

    An inversion of artificial neural networks using a genetic algorithm is presented for a novel concept of optimisation applied to UWB planar antennas of bow-tie type with respect to specified values of antenna performance in the frequency range 3.1-10.6 GHz. This efficient concept is shown to achieve significant reduction in computing time for optimisation. The multidimensional inversion is characterised by a simple composite fitness or target function that includes antenna parameters as a function of signal frequency or/and angle dependence. Good impedance matching and gain performance is achieved over the whole frequency range by adequately modifying the radiating contour profile of the conventional triangular bow-tie antenna. View full abstract»

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  • Narrow-beamwidth T-shaped monopole antenna fabricated from metamaterial wires

    Publication Year: 2008 , Page(s): 180 - 182
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (120 KB)  

    A simple T-shaped monopole is converted into a metamaterial antenna by loading lumped capacitors and inductors on the metal wire. The new metamaterial antenna could sustain a half-wave resonance even when its length exceeds several free-space wavelengths. An 80 mm-long monopole initially resonating at 1.3 GHz is modified to operate at 3.6 GHz with a reduced 3 dB H-plane beamwidth of 48deg. View full abstract»

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  • Parallel-series feed network with improved G/T performance for high-gain microstrip antenna arrays

    Publication Year: 2008 , Page(s): 180 - 182
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (150 KB)  

    A 16 x 8 microstrip antenna array with 28 dB of gain at 18 GHz using a parallel-series feed with reduced conductor traces is presented. The feed network connects antenna elements with about 50% reduction in conductor traces compared to conventional arrays with equal numbers of radiating elements. It also enhances the gain-bandwidth performance of the array and maintains a broadside radiation pattern in a wider frequency band. The full-wave simulation results are verified by means of measurements that demonstrate a relative gain-bandwidth of 4.4% with less than 1 dB of gain ripple. View full abstract»

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  • Simple reconfigurable antenna with radiation pattern

    Publication Year: 2008 , Page(s): 182 - 183
    Cited by:  Papers (24)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (208 KB)  

    A radiation pattern reconfigurable antenna is proposed. By controlling the switch states, the antenna can be worked as a monopole antenna with an omnidirectional radiation pattern or a dipole antenna with reflector, which has directional radiation pattern. Detailed design considerations of the proposed antenna, simulated and experimental results are presented and discussed. View full abstract»

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  • Two-dimensional beam-scanning microstrip leaky-wave antenna

    Publication Year: 2008 , Page(s): 183 - 185
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (154 KB)  

    A novel two-dimensional beam-scanning microstrip leaky-wave antenna (MLWA) is presented. The proposed antenna consists of two half-width MLWA with a phase-shifter. This new type of MLWA has the advantages of two-dimensional beam-scanning and suppressing back lobes. This reduced size MLWA is useful in automotive radar systems and air traffic control. View full abstract»

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  • BioFET sensor for detection of albumin in urine

    Publication Year: 2008 , Page(s): 185 - 186
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (93 KB)  

    Characterisation of a BioFET for detection of albumin in a mixture of human urine is presented. To avoid electrolyte effect of the urine, it was measured in PBS (phosphate buffer saline) at a fixed pH after albumin binding. The drain current was modulated by the albumin bound to the anti-albumin immobilised on the gate surface of the BioFET. The current variation ratio was likely to be proportional to the concentration of the albumin in the range 50-250 mg/1. The results show the feasibility of the BioFET as a urinary albumin sensor. View full abstract»

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  • ZnO transparent thin-film transistors with HfO2/Ta2O5 stacking gate dielectrics

    Publication Year: 2008 , Page(s): 186 - 187
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (150 KB)  

    The performance improvement of ZnO thin-film transistors (TFTs) using HfO2/Ta2O5 stacked gate dielectrics was demonstrated. The ZnO TFTs exhibited transistor behaviour over the range 0-10 V; the field effect mobility, subthreshold slope and on/off ratio were measured to be 1.3 cm2 V-1 s-1, 0.5 V/decade and ~106, respectively. View full abstract»

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  • Er-doped superfluorescent fibre source with enhanced mean-wavelength stability using chirped fibre grating

    Publication Year: 2008 , Page(s): 187 - 189
    Cited by:  Papers (5)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (135 KB)  

    An Er-doped superfluorescent fibre source with enhanced mean-wavelength stability 2 ppm over the 0degC to 70degC range using chirped fibre grating is demonstrated. The effects of the temperature of the fibre, the pump power, the pump wavelength, the pump state of polarisation, and the feedback power have been considered and minimised with corresponding techniques. View full abstract»

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  • Background subtraction using generalised Gaussian family model

    Publication Year: 2008 , Page(s): 189 - 190
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (154 KB)  

    Proposed is a robust method to detect foreground regions from colour video sequences using a generalised Gaussian family model and multiple thresholds. Experiments show that the proposed algorithm works better than conventional approaches in various environments. View full abstract»

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  • Fast dead zone lattice vector quantisation

    Publication Year: 2008 , Page(s): 191 - 192
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (136 KB)  

    A fast method is proposed to determine the quantisation parameters of an entropy constrained lattice vector, called dead zone lattice vector quantisation (DZLVQ). This scheme offers substantial improvement in terms of visual quality with respect to the well-known SPIHT and JPEG2000 algorithms. The tuning of quantisation parameters in variable rate transform coding scheme may involve a critical increasing of the complexity. It is shown that this problem can be solved by a simple iterative procedure using classical LVQ tuning functions. The algorithm ensures a substantial reduction of the complexity while maintaining the compression performance of DZLVQ. View full abstract»

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  • High performance detection filter for impulse noise removal in images

    Publication Year: 2008 , Page(s): 192 - 194
    Cited by:  Papers (5)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (188 KB)  

    A high performance detection (HPD) filter is proposed for impulse noise removal in images. In this approach, the noisy pixels are detected iteratively through several phases, based on a set of unique similarity criteria. Simulation results show that the HPD filter outperforms others at medium to high noise rates and suppresses impulse noise effectively while preserving image details, even thin lines. View full abstract»

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  • Zero-mean proper complex Gaussian random processes through nonlinear channels

    Publication Year: 2008 , Page(s): 194 - 196
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (97 KB)  

    The statistical characterisation of the output of a memory less nonlinear device having, as an input, a zero mean proper complex Gaussian random process is studied. The closed form expression obtained for the high-order moments involved allowed for neat mathematical expressions for the autocorrelation function and the power spectral density of the signal at the nonlinearity output. Parts of the autocorrelation function and of the power spectral density that correspond to the desired signal and to the intermodulation products of different orders are easily identified. View full abstract»

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  • CMOS source degenerated differential active inductor

    Publication Year: 2008 , Page(s): 196 - 197
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (108 KB)  

    A new CMOS source degenerated differential active inductor is proposed. The proposed differential active inductor required only six transistors or more for proper operation. It is very compact compared to a conventional differential active inductor that was design using two differential transconductors and which requires at least ten transistors. The proposed active inductor was fabricated using Silterra 0.18 mum CMOS process for demonstration. Measurement results show that the proposed active inductor has a wide tuning range with a maximum resonance frequency of 7.85 GHz. View full abstract»

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  • Low-power single-to-differential LNA at S-band based on optimised transformer topology and integrated ESD

    Publication Year: 2008 , Page(s): 198 - 199
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (147 KB)  

    A single-ended to differential low-power low-noise amplifier (LNA) designed and implemented in 0.18 mum CMOS technology is presented. The device takes advantage of a current reuse strategy by stacking two common-source differential transistor pair stages for minimum current dissipation, together with the design of optimised high Q differential transformers and inductors in order to minimise the impact of parasitics. The fully integrated, including ESD protection diodes, 2.1 GHz LNA consumes 1.1 mW at 1.2 V supply voltage and presents 29.8 dB gain, 4.5 dB noise figure, -21.1 dBm 1 dB compression point, -11.6 dBm input third-order intercept point and -12.3 dB input return loss performance. View full abstract»

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  • Ultra-low-power clock generation circuit for EPC standard UHF RDID transponders

    Publication Year: 2008 , Page(s): 199 - 201
    Cited by:  Papers (8)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (142 KB)  

    A 0.6 V 720 nW relaxation oscillator fabricated in a standard 0.13 mum CMOS process is proposed as the clock generation circuit for EPC standard UHF RFID transponders. A less than 2% frequency variation is achieved at the frequency of 5.65 MHz when supply voltage varies from 0.6 to 1.0 V. View full abstract»

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  • Athermal Mach-Zehnder interferometer-synchronised arrayed waveguide grating multi/demultiplexer with low loss and wide passband

    Publication Year: 2008 , Page(s): 201 - 202
    Cited by:  Papers (4)  |  Patents (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (64 KB)  

    Described is a silica-based athermal 100 GHz-spacing 40-channel arrayed waveguide grating (AWG) with a Mach-Zehnder interferometer (MZI)-synchronised configuration that employs resin-filled grooves in the AWG and MZI. By suppressing the groove excess loss and using 1.5%-Delta waveguides, a low insertion loss of 3.2 dB and a wide 0.5 dB bandwidth of 45.9 GHz with athermal operation in the -5 to 65degC range and a compact chip size were achieved. View full abstract»

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  • Continuous-wave operation of electrically pumped GaSb-based vertical cavity surface emitting laser at 2.3 mm

    Publication Year: 2008 , Page(s): 202 - 203
    Cited by:  Papers (7)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (72 KB)  

    A novel concept for electrically pumped GaSb-based vertical cavity surface emitting lasers including a structured buried tunnel junction as current aperture is presented. Continuous-wave room temperature operation at 2.325 mum has been achieved. Devices with an aperture diameter of 9 mum show threshold currents of 3.3 mA, threshold voltages of 0.87 V and an output power of 87 muW. View full abstract»

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  • Room-temperature, monolithic, electrically-pumped type-L quantum-well SB-based VCSELS emitting at 2.3 mm

    Publication Year: 2008 , Page(s): 203 - 205
    Cited by:  Papers (4)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (67 KB)  

    An all-epitaxial monolithic vertical cavity surface emitting laser grown on GaSb substrate is presented. The structure is composed of two n-doped AlAsSb/GaSb distributed Bragg reflectors, a type-I GalnAsSb/AlGaAsSb multi-quantum-well active region and a tunnel junction. Quasi continuous-wave laser operation is demonstrated at 2.3 mum up to room temperature. Threshold current densities of 0.8 and 0.6 kA/cm-2 are obtained at 300 and 280 K for 80 mum-diameter devices (1 mus pulses, 10% duty cycle). A peak output optical power of 2 mW was achieved at 280 K. View full abstract»

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  • Wideband tuning of tunable distributed amplification distributed feedback laser array

    Publication Year: 2008 , Page(s): 205 - 207
    Cited by:  Papers (5)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (157 KB)  

    A wide continuous tuning range of 6.7 nm was achieved with a tunable distributed amplification distributed feedback (TDA-DFB) laser by employing an asymmetric periodic structure. A 36-channel operation with a 100 GHz grid was realised for an array of six TDA-DFB lasers integrated monolithically with a coupler and an amplifier. 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.

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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