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Electronics Letters

Issue 6 • Date March 15 2012

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Displaying Results 1 - 25 of 33
  • In brief

    Publication Year: 2012 , Page(s): 300
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  • Interview - Marian Verhelst

    Publication Year: 2012 , Page(s): 300
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  • Full steam ahead for WSNs

    Publication Year: 2012 , Page(s): 301
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  • Parallel protection

    Publication Year: 2012 , Page(s): 302
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  • Directional triple-band planar antenna for WLAN/WiMax access points

    Publication Year: 2012 , Page(s): 305 - 306
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (308 KB)  

    A directional triple-band planar antenna is proposed for WLAN/WiMax access point applications. The triple-band planar antenna consists of a top-loaded dipole for the 2.4 GHz band, two longer dipoles for the 3.5 GHz band and two shorter dipoles for the 5 GHz band. All the dipoles are printed on the same substrate. The triple-band antenna achieves a directional radiation pattern at all the three frequency bands with an antenna gain of 7.5 dBi for the lowest band, 8.5 dBi for the middle band, and 9 10 dBi for the highest band. View full abstract»

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  • Conformal dual patch antenna for diversity based sensor nodes

    Publication Year: 2012 , Page(s): 306 - 307
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (256 KB)  

    A conformal antenna structure based on dual triangular patches is presented. The dual antennas are designed to be used in diversity based sensor node applications and are integrated in the enclosure of the node. The internal shielded enclosure houses the required electronics and power supply. Simulations and measurements show acceptable diversity performance and efficiency in the second resonance mode. View full abstract»

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  • Double directional characterisation of radio wave propagation through metallic watertight doors on board ships

    Publication Year: 2012 , Page(s): 307 - 309
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (352 KB)  

    The objective of this reported work was to characterise electromagnetic wave propagation between adjacent rooms in the lower deck areas of ships. A wideband multiple-input multiple-output channel sounder has been used to realise double directional propagation measurements at 2.2 GHz. The antenna configuration was a linear array at the transmission side and a rectangular one at the reception. The measurement data are first processed with a classic beamforming technique, then with a high resolution algorithm to extract the dominant paths. A ray-tracing based simulation tool is used to understand the measurement results. It is observed that, in spite of the metallic structure of watertight doors, wireless communication remains possible between adjacent rooms after door closure. Results show that electromagnetic waves mainly propagate through door edges openings. View full abstract»

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  • Dual-band PIFA using resonated loop feed structure

    Publication Year: 2012 , Page(s): 309 - 310
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (411 KB)  

    Described is a simple method for exciting a planar inverted-F antenna (PIFA) in order to achieve dual-band operation. The conventional loop feed of a PIFA, formed by the feeding and shorting conductors, is modified by inserting a capacitor into the feeding conductor. The proposed feeding method can provide a wide impedance bandwidth (VSWR=1.5:1) for 2.45 and 5.5=GHz WLAN applications, as well as a small antenna element size. View full abstract»

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  • Miniaturised slits for decoupling PIFA array elements on handheld devices

    Publication Year: 2012 , Page(s): 310 - 312
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (259 KB)  

    A technique for reducing the electromagnetic coupling between planar inverted-F antennas (PIFAs), built on a compact ground plane for typical handheld devices, is presented. Novel miniaturised convoluted slits are inserted in the ground plane between two PIFAs introducing a transmission minimum in the coupling path between them and producing a significant reduction of the mutual coupling within the operating band of the antennas. The proposed slits have a small footprint and are positioned close to the edges of the ground plane, thereby occupying very little space. Simulated results as well as measurements of a fabricated prototype are presented. View full abstract»

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  • CMOS on-chip bio-imaging sensor with integrated micro light source array for optogenetics

    Publication Year: 2012 , Page(s): 312 - 314
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (270 KB)  

    A CMOS-based neural interface device with an integrated blue light-emitting diode array is proposed and demonstrated. The device is designed with target applications in optogenetics in neural and medical sciences, in which local light stimulation of living cells plays a significant role. The design, packaging, and functional demonstrations of the device are presented. View full abstract»

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  • Area scaling analysis of CMOS ADCs

    Publication Year: 2012 , Page(s): 314 - 315
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (217 KB)  

    Recently, the continuing reduction of analogue-to-digital converter (ADC) power consumption has received a lot of attention in the literature, while it is often assumed that converter area does not scale well anymore. An area scaling analysis based on historical data is performed. It is shown that ADC area scaling has been alive and well across all ADC topologies, and for both matching and noise-limited ADCs. View full abstract»

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  • Cheap 0.36 dB NF broadband multipath LNA

    Publication Year: 2012 , Page(s): 315 - 317
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (282 KB)  

    A two-path low-noise amplifier (LNA) designed for the planned MeerKAT radio telescope is presented. The LNA has a noise figure (NF) of less than 0.36 dB and input return loss of less than 12 dB from 0.7 to 1.8 GHz. It consumes 100 mW of power and costs about $10 to manufacture. View full abstract»

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  • Diode string with reduced clamping-voltage for ESD-protection of RF-circuits

    Publication Year: 2012 , Page(s): 317 - 318
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (196 KB)  

    A new diode string based ESD device is proposed. This device, realised in a 0.13 m SiGe BiCMOS process, features a reduced clamping voltage compared to a conventional diode string topology. The addition of extra stages improves the relative reduction in clamping voltage of the device further and, as for a regular diode string, reduces the parasitic capacitance of the device. Hence the proposed circuit constitutes an excellent candidate for double-diode configurations commonly used to protect RF-pads. The proposed architecture is verified by means of simulation and transmission-line pulse tests. Measurement results of a four-stage version of the proposed diode string show a reduction of 28.5 in clamping voltage, realising an absolute clamping-voltage lower than that of a three-stage diode string. View full abstract»

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  • Fast split background calibration for pipelined ADCs enabled by slope mismatch averaging technique

    Publication Year: 2012 , Page(s): 318 - 320
    Cited by:  Papers (4)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (291 KB)  

    A slope mismatch averaging technique which reduces the calibration time and simplifies the digital calibration circuitry in split ADC calibration is introduced. The technique is a direct operation to perform split ADC calibration in pipelined analogue-to-digital converters (ADCs) without any feedback, thus achieving a significant reduction in calibration time. View full abstract»

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  • Improved normalised subband adaptive filter

    Publication Year: 2012 , Page(s): 320 - 321
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (175 KB)  

    Proposed is a subband adaptive filter, which is derived by minimising the sum of the squared Euclidean norms of the differences between the updated tap-weight vector and past tap-weight vectors subject to a set of constraints on the updated tap-weight vector of the adaptive filter. Simulation results show that the misalignment of the proposed subband adaptive filter is low in a relatively high background noise environment. View full abstract»

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  • Monotonic and low-power digitally controlled oscillator with portability for SoC applications

    Publication Year: 2012 , Page(s): 321 - 323
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (133 KB)  

    A monotonic and low-power digitally controlled oscillator (DCO) with a cell-based design for system-on-chip applications is presented. The proposed monotonic DCO not only can achieve high delay resolution and wide operation range at the same time, but also maintain the delay monotonicity. Moreover, based on the proposed varactor-interpolator fine-tuning stage, the proposed DCO can provide monotonic delay with low power consumption and low circuit complexity as compared with conventional approaches. Simulation results of the DCO show that power consumption can be improved to 0.21 mW (at 840 MHz) with 2.95 ps resolution. In addition, the proposed design can be implemented with standard cells, making it easily portable to different processes and very suitable for SoC applications. View full abstract»

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  • Noise suppression in injection-locked ring oscillators

    Publication Year: 2012 , Page(s): 323 - 324
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (250 KB)  

    Presented is a study of the optimal injection frequency using a time-domain model as a technique to improve the noise suppression in injection-locked ring oscillators. It is found that offsetting the injection signal frequency by roughly half of the one-sided lock range relative to the free-running oscillator frequency can lead to higher noise-suppression bandwidth and lower phase noise. Applied to a five-stage ring oscillator, the model shows good agreement with simulations, which indicate that the optimal injection frequency increases the noise-suppression bandwidth by up to 5×, and lowers the phase noise by 15dB. View full abstract»

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  • Dependence of electromagnetic immunity of microcontrollers on system clock frequency

    Publication Year: 2012 , Page(s): 324 - 326
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (236 KB)  

    To test and to model the conducted radio frequency electromagnetic immunity of a reconfigurable integrated circuit like microcontrollers is complex because the configuration parameter is variable. A study is presented of the dependence of immunity on one of the configuration parameters - the system clock. The theoretical analysis shows that the immunity is independent of the clock frequency in the frequency range of interest. Measurement results support the theoretical prediction. View full abstract»

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  • Efficient random variable generation: Ratio of uniforms and polar rejection sampling

    Publication Year: 2012 , Page(s): 326 - 327
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (223 KB)  

    Monte Carlo techniques, which require the generation of samples from some target density, are often the only alternative for performing Bayesian inference. Two classic sampling techniques to draw independent samples are the ratio of uniforms (RoU) and rejection sampling (RS). An efficient sampling algorithm is proposed combining the RoU and polar RS (i.e. RS inside a sector of a circle using polar coordinates). Its efficiency is shown in drawing samples from truncated Cauchy and Gaussian random variables, which have many important applications in signal processing and communications. View full abstract»

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  • Worst-case flow model of VL for worst-case delay analysis of AFDX

    Publication Year: 2012 , Page(s): 327 - 328
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (176 KB)  

    Worst-case delay analysis is important for avionics full duplex switched Ethernet (AFDX) standardised as ARINC 664. The flow model of virtual link (VL) in the worst-case delay analysis of AFDX is inaccurate, which depends only on the parameters of VL and ignores the impact from the network, so it makes the worst-case delay analysis of AFDX impractical. A worst-case flow model of VL, which takes the worst impact from the network into account, is proposed to mend the worst-case delay analysis of AFDX. This worst-case flow model of VL is applied in one of the main theoretical approaches for worst-case delay analysis, the network calculus approach. It assists the network calculus approach to get the real upper bound of delay for VL. View full abstract»

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  • First working prototype of composite clock

    Publication Year: 2012 , Page(s): 329 - 330
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (262 KB)  

    A composite clock layout and results are presented. This apparatus combines the stability of several reference clocks for different durations. A voltage-controlled quartz oscillator is driven by a hydrogen maser clock for mid-term stability and by a caesium atomic clock for long-term stability. The best clock stability at a given averaging time is transferred to the voltage-controlled oscillator by a special control system using two commands. View full abstract»

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  • High isolation diplexer using quarter-wavelength resonator filter

    Publication Year: 2012 , Page(s): 330 - 331
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (352 KB)  

    A microstrip diplexer with very high isolation is presented. The diplexer consists of two compact filters with quarter-wavelength resonators coupled by the metallised vias. Each metallised via is inductive and behaves as a K-inverter. This type of filter has two adjustable transmission zeros on each side of the passband, which can be shifted by changing the coupling coefficient between the source and load. By locating the transmission zero of one channel at the passband of the other channel, very high isolation of the diplexer can be achieved. Simulated results of the fabricated diplexer agree well with measured results. View full abstract»

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  • Compact and broadband microstrip-to-waveguide transition using antisymmetric tapered probes

    Publication Year: 2012 , Page(s): 332 - 333
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (211 KB)  

    A compact and broadband microstrip-to-waveguide transition using antisymmetric tapered probes is proposed. The proposed transition has 47.4% fractional bandwidth for which the return loss is larger than 15%dB, covering the whole frequency range 8-13 GHz. As compared with the microstrip-to-waveguide transition using the tapered CPS probe, the 15%dB fractional bandwidth is increased from 35 to 47.4% along with 44.8% reduction in the transition size. To verify the simulation result, a back-to-back transition has been fabricated and measured, and the measurement result shows good agreement with the simulation result. View full abstract»

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  • Compact microstrip square open-loop bandpass filter using open stub

    Publication Year: 2012 , Page(s): 333 - 334
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (420 KB)  

    A novel compact stub-coupled microstrip square open-loop bandpass filter (BPF) is proposed. The fork-shaped open stub is internally inserted inside the square loops using open gaps. The BPF has strong electric coupling, because the open sides of the two loops are proximately placed face-to-face in parallel. The rectangular stubs attached to the internal wall of loops connect to magnetic couplings; as a result the mixed coupling generates strong electromagnetic (EM) coupling in the BPF with an adequate input reflection coefficient at a centre frequency of 11.94 GHz. The measured results of the designed BPF exhibited return loss and insertion loss of 24.8 dB and 1.7 dB, respectively. View full abstract»

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  • Improved NRZ transmission distance at 20 Gbit/s using dual electroabsorption modulated laser

    Publication Year: 2012 , Page(s): 335 - 336
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (261 KB)  

    An error-free 39.7 km transmission for a 20 Gbit/s NRZ signal in standard dispersion fibre without dispersion compensation is carried out both experimentally and by simulation using the dual electroabsorption modulated laser (D-EML). The D-EML comprises an integrated electroabsorption modulated laser with dual independent-access modulation. Its ability to adjust the laser and modulator chirp by controlling the amplitude modulation leads to transmission distance enhancement with lower power consumption, cost and device complexity. 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