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Electronics Letters

Issue 10 • Date May 10 2012

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Displaying Results 1 - 25 of 44
  • In brief

    Publication Year: 2012 , Page(s): 534
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  • Interview

    Publication Year: 2012 , Page(s): 534
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  • close to tiers

    Publication Year: 2012 , Page(s): 535
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (179 KB)  

    A new class of RF switches have been developed by MIT Lincoln Laboratory in the US. The single chip high-performance vertically stacked switches are based on a wafer-scale 3D integration technology, and have a footprint that is much smaller than in conventional 2D switches. The approach, which is fully compatible with the standard Si CMOS process, could also be used for other types of circuit such as amplifiers, signal processors and imagers. View full abstract»

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  • intense resonance

    Publication Year: 2012 , Page(s): 536
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    Researchers from the Tokyo Institute of Technology have demonstrated a direct modulation of the output power of a resonant tunnelling diode (RTD) oscillator and measured its frequency response in the THz frequency range. They have also achieved wireless data transmission at 542 GHz, the first report of wireless communication in this range. View full abstract»

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  • Design of narrow bandwidth elliptic-type SAW/BAW filters

    Publication Year: 2012 , Page(s): 539 - 540
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    The passband width obtained in the SAW/BAW filter is inherently limited by the electromechanical coupling factor K2 of piezoelectric substrate. Proposed is a new design technology to flexibly control the passband width without sacrificing insertion loss, out-of-band rejection and steepness of the transition bands. A bandpass LC filter has been designed based on the traditional elliptic filter design. The LC resonators are replaced with SAW/BAW resonators in this filter and the design of the resonators is optimised to suppress passband ripples generated by finite capacitance ratio γ. It revealed that filters with different relative bandwidth are easy to design using one piezoelectric substrate. This technique is applied to the design of a SAW filter fabricated on the Cu-grating/15°YX-LiNbO3 structure. View full abstract»

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  • Bandwidth limits for lossless planar arrays over ground plane

    Publication Year: 2012 , Page(s): 540 - 542
    Cited by:  Papers (9)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (205 KB)  

    Maximum bandwidth limits are developed for lossless planar arrays over a ground plane through use of Fano's broadband impedance matching method and Richards' transformation. It is demonstrated that such an array cannot exceed 8.3:1 bandwidth without material loading (for VSWR'2). It is also demonstrated that an additional dielectric superstrate layer can provide up to 12.1:1 bandwidth, without magnetic or lossy substrates. A simple analytic expression for the maximum bandwidth is given as a function of impedance mismatch (VSWR) and substrate material parameters. The dependence of bandwidth on aperture complexity is quantified, showing that a simple first-order aperture has a bandwidth limit of 5:1, without material loading. View full abstract»

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  • Broadband circularly polarised slot antenna array for L- and S-band applications

    Publication Year: 2012 , Page(s): 542 - 543
    Cited by:  Papers (5)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (185 KB)  

    A new design of a broadband circularly polarised square slot antenna array (CPSSAA) fed by a symmetric coplanar waveguide (CPW) for L- and S-band applications is presented. The proposed antenna is composed of 2×2 CPSS antennas and a sequentially rotated feed network. In this model, compared with the previous CPSSAA with an asymmetric fed structure, the impedance bandwidth of the antenna is increased, and is 71% wider than the impedance bandwidth of a previous similar design. The designed antenna operates over the frequency band 1-4.34 GHz (4.34:1, 125%) for VSWR <; 1.6 exhibiting a 120% (1.11-3.98 GHz, 3.58:1) circular polarisation bandwidth. The proposed CPSSAA can provide a peak gain of about 8.9 dBic at 3 GHz, with gain variations less than 1.5 dB at operating frequencies. Measured and simulated results validate the proposed design. View full abstract»

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  • Design of multi-band CPW-fed antenna for triple-frequency operation

    Publication Year: 2012 , Page(s): 543 - 545
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (467 KB)  

    Presented is a coplanar waveguide fed antenna for multi-band operation covering the digital video broadcasting signal reception in the UHF band, mobile communications in the GSM band, and the 2.4 GHz 802.11g/n band. The size of the designed antenna is 114×60 mm and it is printed on an FR4 substrate of thickness 0.8 mm with dielectric constant 4.4. It has an inner U-shaped strip enclosed by an outer loop strip and the outer loop strip is designed to obtain a wide operating bandwidth. Experimental results show that the proposed antenna exhibits a good impedance matching over a wide frequency range of 470 to 960 MHz, 1450 to 1880 MHz, and 2.4 to 2.6 GHz. View full abstract»

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  • Measurements and prediction of outage intensity owing to rain attenuation

    Publication Year: 2012 , Page(s): 545 - 546
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (267 KB)  

    Measured data of rain attenuation from 19 terrestrial line-of-sight links, operating in frequencies from 14.5 to 83.5 GHz, were analysed to provide statistics of fade durations as a function of the attenuation threshold. From these results, an empirical method for predicting outage intensity owing to rain attenuation was derived, that shows good agreement with the measurements and allows the calculations of required link margins. View full abstract»

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  • Yagi antenna with improved out-of-band gain suppression

    Publication Year: 2012 , Page(s): 546 - 548
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (300 KB)  

    Presented is a Yagi antenna with improved out-of-band gain suppression to reduced the demands on the front end band filter. Two parasitics close to the fed element are used to increase the Q-factor of that element, and the length and position of the other directors and reflectors are optimised to suppress the out-of-band gain. Simulated and measured results show that the proposed antenna has the characteristics of a conventional Yagi antenna in the passband, albeit with a narrower bandwidth, whilst providing more than 10 dB of gain suppression to interference signals located outside the band. View full abstract»

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  • Minimal readout scheme for ISFET sensing arrays based on pulse width modulation

    Publication Year: 2012 , Page(s): 548 - 549
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (281 KB)  

    Proposed is an ISFET readout scheme with minimum analogue components to minimise parasitic and noise effects in large-scale chemical sensing arrays. For each array pixel, a pair of complementary ISFETs shares the same floating gate in an inverter configuration. An additional electrical input is capacitively coupled to the same floating gate with a periodic reference signal input. In this way, the conventional ISFET analogue output is replaced by a chemically controlled pulse width modulated signal. Theoretical analysis and experimental results show a pulse width pH sensitivity of around 6%, of the input reference signal period, per pH. This is achieved along with %1%V offset suppressing capability. View full abstract»

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  • ISFET-based chemical Schmitt trigger

    Publication Year: 2012 , Page(s): 549 - 551
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (267 KB)  

    Ion sensitive field effect transistors (ISFETs) are pH sensors that have generally been used in the analogue domain. It is possible to use them in the digital domain for chemical thresholding applications. To facilitate small pH change detection where a simple switch suffers from ripple and distorted output, a chemical switch with input noise immunity is needed. Reported are first measurements of an ISFET-based chemical Schmitt trigger. It provides a more stable output with better noise immunity. It can be used in applications where the digital detection of small pH changes is required. View full abstract»

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  • Power efficient output stage for high density implantable stimulators

    Publication Year: 2012 , Page(s): 551 - 552
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (152 KB)  

    In implantable stimulators, a current-controlled stimulation is preferred over a voltage-controlled one due to its safety. However, the power efficiency is a major disadvantage. By reducing the headroom voltage needed in the current driver, power efficiency of a constant current stimulation is improved. A promising technique is to bias the transistor in the triode region whereby improving output impedance through the regulated cascode structure. This comes with a feature of an implicit compliance monitor. Proposed is a new power efficient high compliance output stage. View full abstract»

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  • 0.07 mm2, 2 mW, 75 MHz-IF, fourth-order BPF using source-follower-based resonator in 90 nm CMOS

    Publication Year: 2012 , Page(s): 552 - 554
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (300 KB)  

    A highly-transistorised bandpass filter (BPF) using a source-follower-based (SFB) resonator is proposed. It benefits from the advantageous properties of the source follower (e.g. no parasitic pole, linear VGS I/O relationship, high-input and low-output impedances), while combining it with a compact and low-power grounded differential active inductor to synthesise the complex poles. Fabricated in 90 nm CMOS, a fourth-order 75 MHz-IF BPF prototype merging two such SFB resonators measures a 10 MHz bandwidth at 2 mW of power. The die size is merely 0.07 mm2. View full abstract»

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  • CMOS 138 GHz low-power active mixer with branch-line coupler

    Publication Year: 2012 , Page(s): 554 - 555
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (341 KB)  

    A 138 GHz down-conversion mixer with a branch-line coupler has been developed based on a 90 nm CMOS technology. The fabricated mixer shows a differential conversion gain of 3.7 dB with the mixer core drawing a current 0.66 mA from a 1.2 V supply. The 1 dB gain compression point is estimated to be larger than 6 dBm. The mixer occupies 0.61 0.62 mm2 of chip area excluding pads. View full abstract»

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  • Cellular nonlinear network controller for dynamic thermal management

    Publication Year: 2012 , Page(s): 555 - 557
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (244 KB)  

    The dynamic thermal management problem is posed for multi-processing element (multi-PE) computing systems (which can support both dynamic re-parallelisation of tasks across PEs and their operating frequencies) as a multi-constraint optimisation problem. Proposed is a cellular nonlinear network controller as an online solver of this problem. Results obtained through a simulation model are presented followed by a brief overview of pertinent literature. View full abstract»

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  • Double noise coupling ΔΣ analogue-to-digital converter

    Publication Year: 2012 , Page(s): 557 - 558
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (301 KB)  

    A novel ΔΣ analogue-to-digital (ADC) architecture is proposed for second-order noise shaping enhancement. The new architecture is less dependent on the opamp DC gain than the earlier ΔΣ ADC with second-order noise shaping enhancement. Also, the proposed architecture reduces the complexity of the clock generator and zero optimisation compared to the earlier one. A ΔΣ ADC using the new configuration was designed and simulated. The results verify the advantages of the proposed structure. View full abstract»

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  • Fast median calculation method

    Publication Year: 2012 , Page(s): 558 - 560
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (182 KB)  

    The ever increasing demand for high image quality requires fast and efficient methods for noise reduction. The best-known order-statistics filter is the median filter. A method is presented to calculate the median on a set of N W-bit integers in W/B time steps. Blocks containing B-bit slices are used to find B-bits of the median; using a novel quantum-like representation allowing the median to be computed in an accelerated manner compared to the best-known method (W time steps). The general method allows a variety of designs to be synthesised systematically. A further novel architecture to calculate the median for a moving set of N integers is also discussed. View full abstract»

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  • Multi-stage noise band cancellation ΣΔ modulator for digitisation of distorted signals

    Publication Year: 2012 , Page(s): 560 - 562
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (319 KB)  

    A new sigma-delta modulator (ΣΔM) architecture is proposed to digitise wideband distorted signals. It combines frequency band decomposition with bandpass (BP) ΣΔ converters and cascaded architectures. The novelties are the use of the residual signal transfer function at the output of the first summing node in a classical BP ΣΔ that is an almost free signal shaping in the ΣΔM and the digitisation of the shaped noise in order to cancel it out in a particular band. View full abstract»

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  • Time difference amplifier design with improved performance parameters

    Publication Year: 2012 , Page(s): 562 - 563
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (204 KB)  

    Time difference amplification is a technique which has been developed previously to facilitate the measurement of temporal events in circuits whose magnitudes are decreasing with the advances in technology. A technique is proposed which extends the time input difference (ΔTinput) range achieved by current methods from 40 to 70 ps. View full abstract»

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  • Modified angular radial partitioning for edge image description in image retrieval

    Publication Year: 2012 , Page(s): 563 - 565
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (322 KB)  

    An angular radial partitioning (ARP) method divides an edge image into M×N partitions in order to make its compact image descriptor. However, it inherently suffers from a boundary problem that arises when edge pixels exist near the partition boundaries. Proposed is a modified ARP (mARP) to reduce degradation of retrieval performance caused by the boundary problem. For comparison, image retrieval tests have been carried out using the above two methods. The results demonstrate that the retrieval performance of the mARP is almost twice as good as that of the original one. View full abstract»

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  • Field-programmable true random number generator

    Publication Year: 2012 , Page(s): 565 - 566
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (333 KB)  

    True random number generation is crucial in cyber-security applications. Proposed is a voltage-controlled true random number generator that is inherently field-programmable. This facilitates increased entropy as a randomness source because there is more than one configuration state which lends itself to more compact and low-power architectures. It is evaluated through electrical characterisation and statistically through industry-standard randomness tests. To the best of the author's knowledge, it is one of the most efficient designs to date with respect to hardware design metrics. View full abstract»

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  • Digital predistortion technique with in-band interference optimisation applied to DVB-T2

    Publication Year: 2012 , Page(s): 566 - 568
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (211 KB)  

    The efficient transmission and nonlinear modelling of orthogonal frequency division multiplexing (OFDM) signals are difficult to address owing to the special characteristics of this modulation scheme. Proposed is a digital predistortion technique suitable for the implementation in an OFDM transmitter to optimise the in-band interference caused by the nonlinear distortion generated in the amplification chain. The approach is experimentally validated by its application in one of the world's most advanced broadcasting systems, achieving an outstanding linearisation performance in the transmitter; specially for the in-band interference, a modulation error ratio (MER) of 42.1 dB is obtained. View full abstract»

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  • Effect of class clustering on delay differentiation in priority scheduling

    Publication Year: 2012 , Page(s): 568 - 570
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (101 KB)  

    Priority scheduling is the most viable way to implement QoS differentiation in telecommunication networks. Most studies on priority scheduling do not take into account possible class clustering. In particular, they assume that different classes occur randomly and independently in the arrival stream of packets. In reality, however, packets of the same class may have the tendency to arrive in clusters. By using existing results, it is shown that class clustering may have a severe impact on the achievable delay differentiation in priority scheduling. View full abstract»

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  • Ultra-compacted sub-terahertz bandpass filter in 0.13 mm SiGe

    Publication Year: 2012 , Page(s): 570 - 571
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (404 KB)  

    The design of an ultra-compacted silicon-based bandpass filter in the sub-terahertz frequency range is explored. A filter with combline topology consisting of multilayered resonators and a cross-coupling capacitor has been designed in 0.13 μm SiGe. The dimensions of the implemented filter are 40 × 130 μm2, which are even smaller than a ground-signal-ground probing pad with 100 μm pitch. Meanwhile, the filter achieves a 3-dB bandwidth of about 32.0-GHz (22.0%) and an insertion loss of -7.7 dB at the centre frequency of 143 GHz. 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