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Electronics Letters

Issue 24 • Date November 24 2011

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Displaying Results 1 - 25 of 32
  • In Brief

    Publication Year: 2011 , Page(s): 1302
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  • Interview

    Publication Year: 2011 , Page(s): 1302
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (171 KB)  

    Dr Thomas Fickenscher from Helmut Schmidt University talks about his research and his Letter 'Underwater wireless optical communication for swimmer feedback using IrDA transceiver' on page 1335. View full abstract»

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  • Inside View

    Publication Year: 2011 , Page(s): 1303 - 1304
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    10.5 W substrate-emitting lasers from researchers in Germany and Russia show promise for coherent laser stacks that could replace solid state-lasers in material processing and other applications. Nikolay Ledentsov tells us more. View full abstract»

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  • MIMO wraps up

    Publication Year: 2011 , Page(s): 1304
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (241 KB)  

    Researchers at Tsinghua University have taken a 3D approach to MIMO antennas and have built a 2.4 GHz MIMO antenna for WLAN applications that is much smaller than previous designs but still has high isolation and good omnidirectional coverage. The spectrum efficiency and transmission quality of wireless communication systems are improved through the use of multiple antennas at both the transmit and receive ends. MIMO antennas are being widely researched at the moment as they enable the use of the spatial degree of freedom in a wireless multipath channel, and they form a key technology for future wireless communication systems such as 3GPP, LTE, WiMAX 802.16, IEEE 802.20 and IMT-Advanced. At the moment MIMO antennas are only adopted in some large static base stations. This is because in these space-separated antenna arrays, nearly half of the wavelength is needed to achieve acceptable isolation; about 15 dB for most situations. In modern communication systems, the space is limited in both the base stations and the mobile terminals, and as the antennas shrink in size, the mutual coupling between the elements increasingly restricts the performance. The design of antennas for a space-limited MIMO system is therefore still a challenge. View full abstract»

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  • Compact CPW-fed rotated square-shaped patch slot antenna with band-notched function for UWB applications

    Publication Year: 2011 , Page(s): 1307 - 1308
    Cited by:  Papers (7)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (222 KB)  

    A novel coplanar waveguide (CPW)-fed slot antenna with bandstop characteristics is presented for ultra-wideband (UWB) applications. The proposed antenna consists of a rotated square-shaped patch and a 50Ω CPW feed line. By embedding an inverted V-shaped slot with folded ends, the band rejection property is achieved. Also, etching two slots on the ground plane leads to an improvement in impedance bandwidth. The proposed antenna covers the frequency range of 3.04-20.22 GHz for VSWR <; 2, and rejects 5-6 GHz. The total size of the antenna is 20 × 18 × 1.6 mm3, which is smaller than many of the designed slot antennas and covers wider bandwidth. For the fabricated antenna, an omnidirectional pattern is observed over the whole UWB frequency range. View full abstract»

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  • Indoor 2.4 GHz microwave propagation study using 3D FDTD approach

    Publication Year: 2011 , Page(s): 1308 - 1309
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (230 KB)  

    A full three-dimensional (3D) finite difference time domain (FDTD) approach has been developed to model microwave indoor propagation at 2.4 GHz. Simulations take into account traditional office furniture, dielectric walls, windows etc. Owing to the large computation resources needed to perform the 3D simulations, the algorithm was implemented on a cluster using a parallel computing technique. FDTD results are compared with a multi-wall model and measured data. Good agreement between FDTD and measurements is reported. View full abstract»

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  • Block-run-based connected component labelling algorithm for GPGPU using shared memory

    Publication Year: 2011 , Page(s): 1309 - 1311
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (217 KB)  

    An efficient two-scan connected component labelling (CCL) algorithm is proposed for a general purpose graphics processing unit (GPGPU). Compared to other GPU CCL algorithm, this algorithm has three distinct features. First, block-based and run-based strategies are combined in the first scan to simplify the equivalence label resolving process. Secondly, a novel labelling method for the GPU is introduced by constructing a forest of rooted trees using only 16-bit value for each node. Thirdly, the whole algorithm can be implemented in the GPU shared memory and minimise global memory bandwidth consumption. Experiments show that the algorithm achieves a speedup of between two and five times compared to other state-of-the-art GPU and CPU CCL algorithms. View full abstract»

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  • Hybrid duty-cycle corrector circuit with dual feedback loop

    Publication Year: 2011 , Page(s): 1311 - 1313
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (314 KB)  

    A two-stage duty amplifier (TDA)-based hybrid duty-cycle corrector (HDCC) circuit with a dual feedback loop is presented. The proposed TDA-based HDCC has improved loop stability and increased isolation as compared to other duty-cycle correctors (DCCs), resulting in a large duty-cycle correction range of up to ±30% over a wide frequency range of 0.5-2.0 GHz. It can also support a power-down mode with fast transition to active mode. The measured duty-cycle error is less than ±1.49% over an input duty-cycle range of 20-80% for 0.5-2.0 GHz. The HDCC is fabricated in a 0.18 μm CMOS process and occupies an area of only 0.043 mm2. View full abstract»

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  • Low-power pulse-triggered flip-flop design using gated pull-up control scheme

    Publication Year: 2011 , Page(s): 1313 - 1314
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (255 KB)  

    A new implicit type pulse triggered flip-flop design aimed at solving a common transistor stacking problem is presented. A pull-up transistor gating scheme is devised to avoid a bulky discharging path causing excessive power consumption. Via a bootstrap technique, the required gating pulse signal is obtained free from a modified delay inverter design. Circuit analyses and post-layout simulations are provided to prove the superiority of the design in terms of layout area and power-delay product. View full abstract»

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  • Output impedance analysis of digital-to-analogue converters

    Publication Year: 2011 , Page(s): 1314 - 1316
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (193 KB)  

    The main fundamental limitation of the dynamic performance of digital-to-analogue converters is their dynamic output impedances. Detailed analysis of the output impedance is provided in this Letter. A new formula is proposed to reveal that the change of output impedance during the input codes switching is the real limitation factor. To reduce this output impedance variation, two possible solutions are suggested and analysed. View full abstract»

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  • Two-path double delay line based bandpass quadrature ΣΔ modulator

    Publication Year: 2011 , Page(s): 1316 - 1317
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (414 KB)  

    A design technique for a double-delay based quadrature ΣΔ modulator is presented. The architecture uses a two-path scheme, which avoids mirror tones in the signal band and locks the intermediate frequency with the clock, thus avoiding the trimming requirement. The two-path architecture and time interleaving lead to an overall power reduction by a factor of 8. View full abstract»

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  • Enhanced EBG-patterned PDN for suppressing power plane noises

    Publication Year: 2011 , Page(s): 1317 - 1319
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (283 KB)  

    A novel EBG-patterned P/G planes structure is proposed as a means of minimising the effects of a discontinuous reference plane as well as suppressing the propagation of noise. The performance of the proposed structure has been validated and investigated experimentally. View full abstract»

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  • Numerical study of spatial correlation in reverberation chamber

    Publication Year: 2011 , Page(s): 1319 - 1320
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (212 KB)  

    The spatial correlation in a reverberation chamber as a function of either the wavelength or the displacement is discussed. It is shown that the results from simulations are consistent with theory when the wavelength is changed. However, when the receiver is moved in the reverberation chamber, the spatial correlation differs from theory. View full abstract»

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  • Image feature extraction via local tensor rank one discriminant analysis

    Publication Year: 2011 , Page(s): 1320 - 1321
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (106 KB)  

    A novel supervised image feature extraction method, called local tensor rank one discriminant analysis (LTRODA) is proposed. LTRODA learns a series of rank one tensor projections with orthogonal constraints to produce compact features for images. To seek the optimal projections with prominent discriminative ability, LTRODA carries out local discriminant analysis. LTRODA is free from the matrix singularity problem owing to its trace difference based learning model, and a novel solving method ensures stability of the solution. Experimental results suggest that LTRODA provides a supervised image feature extraction approach of powerful pattern-revealing capability. View full abstract»

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  • Compact capacitive compensated directional coupler using planar artificial transmission lines

    Publication Year: 2011 , Page(s): 1321 - 1323
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (219 KB)  

    A novel compact directional coupler based on planar artificial transmission lines is proposed. Interdigital capacitors are introduced to compensate for the odd-mode phase velocity in order to achieve a high directivity. The size of this proposed coupler is about 25% that of a conventional one. A 20 dB directional coupler at 900 MHz has been designed and fabricated. The directivity reaches 36 dB at the centre frequency. The design, simulation and measurements are presented. View full abstract»

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  • Identification technique of FET model based on vector nonlinear measurements

    Publication Year: 2011 , Page(s): 1323 - 1324
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (172 KB)  

    A new modelling approach which exploits only vector nonlinear measurements is described. The parameters of the I-V and Q-V non-linear constitutive functions are identified by combining low- and high-frequency large-signal measurements with a numerical optimisation routine. Low-frequency dispersion manifesting in the I-V characteristics is also correctly accounted for. As a case study a gallium nitride HEMT on silicon carbide substrate is considered and very good agreement between measurements and simulation is achieved. View full abstract»

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  • Discrete-time charge-domain filter with charge buffer for flexible design of FIR filter

    Publication Year: 2011 , Page(s): 1325 - 1326
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (408 KB)  

    A discrete-time charge-domain filter (CDF) with wide bandwidth and high attenuation is proposed. By employing a charge buffer with timing control to move a sampled charge between capacitors, the CDF can reduce the number of pulses and select a decimation rate effectively. Measurement showed 13 MHz bandwidth and 88.86 dB attenuation in a 90 nm CMOS process. View full abstract»

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  • Electronically switchable bulk acoustic wave resonator based on paraelectric state ferroelectric films

    Publication Year: 2011 , Page(s): 1326 - 1327
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (144 KB)  

    The electromechanical properties of multilayer microwave capacitance structures with two ferroelectric films in the paraelectric state are analysed. A film bulk acoustic wave resonator (FBAR) with about two times (approximately octave) resonance frequency switching is demonstrated. The switching phenomenon is due to the application of a unidirectional or oppositely directed DC control E-field to ferroelectric layers that results in the excitation of different acoustic eigenmodes in the resonator structure. View full abstract»

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  • Compact microstrip dual-band filter with stepped-impedance resonators

    Publication Year: 2011 , Page(s): 1328
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (331 KB)  

    Summary form only given. A microstrip dual-band filter using a stepped-impedance resonator is proposed. The designed filter is centred at 1.68/2.99GHz. It can provide two passbands, one in the L-band and one in the S-band. The relative bandwidth of both bands were 3.27 and 2.85%. The size of the proposed filter is 52.2mm in width and 40mm in length. The filter achieved insertion loss of less than ldB and return loss of greater than 20dB in each band. The isolation between these two pass bands is better than 25dB from 1.96 to 2.59 GHz. The filter is analysed and designed by Sonnet software. It is shown that the theoretical analysis and simulated performances are in good agreement. View full abstract»

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  • Transformed lumped element integrated passive bandpass filters for gigahertz range spectrum monitor receivers

    Publication Year: 2011 , Page(s): 1328 - 1330
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (331 KB)  

    Two integrated bandpass filters have been designed and fabricated on standard 130 nm CMOS technology. The lumped element, third-order Butterworth bandpass filters at 9.45 and 1.75 GHz are designed for sub-band filtering in a spectrum monitoring receiver function in a future cognitive radio. A series coupled resonator topology is selected and a novel delta-star transformation technique is applied to obtain element values suitable for reliable fabrication on an integrated circuit. Occupying die areas of 780 × 200 μm and 1750 × 500 μm each, the filters achieve insertion losses of 15.6 and 8.6 dB, and band-widths of 1 GHz and 210 MHz, respectively, which are suitable for the chosen spectrum monitor receiver architecture. View full abstract»

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  • Ultra-wideband bandpass filter based on transversal signal-interaction concepts

    Publication Year: 2011 , Page(s): 1330 - 1331
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (304 KB)  

    An ultra-wideband (UWB) bandpass filter based on transversal signal-interaction concepts is proposed. By cascading a planar Marchand balun and two transmission lines with different electrical lengths, a new UWB bandpass filter (fractional bandwidth 86-111.5%) with two transmission zeros close to the passband is realised. Good agreement is observed between the simulated and measured results. View full abstract»

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  • Performance analysis of APD-based photon polarisation modulation system in turbulent atmosphere

    Publication Year: 2011 , Page(s): 1332 - 1333
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (123 KB)  

    To improve the data rate in laser communication systems, a new modulation scheme, which uses the photon polarisation property, is proposed. Performance analysis and Monte-Carlo simulation are made, considering both non-turbulent and heavy-turbulent atmospheric conditions. The simulation results show that the data rate is twice as much as that of pulse-position modulation in a broad range of optical link efficiency. View full abstract»

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  • Reduction of backscattering noise in 2.5 and 10 Gbit/s RSOA-based WDM-PON

    Publication Year: 2011 , Page(s): 1333 - 1335
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (303 KB)  

    Rayleigh backscattering (RBS) causes significant power penalty in a centrally light-seeded wavelength division multiplexed passive optical network (WDM-PON). In this reported work, the RBS noise in a WDM-PON based on a reflective semiconductor optical amplifier (RSOA) is successfully mitigated by means of noise predictive equalisation. Conventional equalisers are implemented at the receiver with an additional noise canceller that can estimate and reduce the reflection noise. It is experimentally demonstrated that the proposed equaliser enhances the reflection tolerance significantly at data rates of 2.5 and 10 Gbit/s to -8.5 and -16.5 dB, respectively. View full abstract»

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  • Underwater wireless optical communication for swimmer feedback using IrDA transceiver

    Publication Year: 2011 , Page(s): 1335 - 1336
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (204 KB)  

    Effective short-distance communication of real-time data from sensors on the body of a competitive swimmer to a head-up display faces a number of environmental problems. Presented are the benefits of utilising IrDA transceivers for wireless optical underwater communications using timing jitter as a measure of the link performance looking at the impact of air bubbles and transmission through the water surface. A number of conclusions are drawn for improving the link performance without increasing the limited power budget of battery-driven devices. View full abstract»

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  • Carrier transport and its variation of laser-lateral-crystallised poly-Si TFTs

    Publication Year: 2011 , Page(s): 1336 - 1338
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (206 KB)  

    Carrier transport in continuous-wave laser lateral-crystallised (CLC) poly-Si thin film transistors (TFTs) has been investigated. Large Si grains formed by the laser crystallisation, enhanced electron mobility of the CLC poly-Si TFT. It was found that the effective electron mobility was free from grain boundary scattering and was mainly governed by phonon scattering; its variation, however, was governed by the number of grains in the channel region. 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