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Electronics Letters

Issue 15 • Date July 21 2011

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Displaying Results 1 - 25 of 36
  • In brief

    Page(s): 832
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  • Interview

    Page(s): 832
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (99 KB)  

    Professor Xinliang Zhang from Wuhan Nati onal Laboratory for Optoelectronics in China talks about his Let ter '40 Gbit/s four-input photonic digital priority encoder employing three parallel semiconductor optical amplifiers?? on page 872. View full abstract»

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  • Inside view

    Page(s): 833
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  • Pores for thought

    Page(s): 834
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (220 KB)  

    A team at the University of California Santa Cruz (UCSC) has developed the first amplifier that is optimised specifically for solid-state nanopore sensor applications. Their miniaturised patch-clamp amplifier, which is cheaper and smaller than the commercial bench top multi-purpose alternative, achieves a comparable performance and overcomes the dead time problem inherent in existing amplifiers. View full abstract»

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  • Compact circularly-polarised slot antenna for UWB applications

    Page(s): 837 - 838
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (341 KB)  

    A simple compact broadband circularly-polarised square slot antenna (CPSSA) fed by a coplanar waveguide is presented. A CP bandwidth larger than 38.2% can be attained simply by embedding two inverted-L grounded strips around two opposite corners whereas the impedance bandwidth can be greatly improved through the tuning stubs. The designed CPSSA antenna is 25 × 25 × 0.8 mm3, which is 56% smaller than previous CPSSA structures operating over the frequency band between 2.9 and 11.2 GHz for VSWR <; 2. View full abstract»

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  • Compact UWB antenna with sharp band-notched characteristics for lower WLAN band

    Page(s): 838 - 839
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (265 KB)  

    A compact ultra-wideband (UWB) antenna with sharp band-notched characteristics is presented. The sharp band-notched characteristic is realised by inserting a half wavelength C-shaped slot in the patch and adding two half wavelength stepped impedance resonators around the feed-line. Simulated and experimental results show that the designed antenna, with compact size of 30 × 36 mm2, has an impedance bandwidth of 3.1-10.6 GHz for return loss less than -10, except the lower WLAN band of 5.15-5.35 GHz (return loss >; -5 dB). The ratio of -5 dB notched bandwidth to -10 dB notched bandwidth is 0.79. Moreover, the antenna has good omnidirectional radiation patterns in the H-plane. View full abstract»

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  • Robust adaptive array using Taylor series expansion

    Page(s): 840 - 841
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (143 KB)  

    In the presence of pointing errors, a robust beamforming method is suggested which finds a new steering vector based on the Taylor series expansion of the one initially given. The problem of finding the new steering vector is formulated as the closed form of a generalised eigenvalue problem, which allows one to readily solve it. The proposed method can deal with a wide range of pointing errors. View full abstract»

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  • Best subsequence selection of heart sound recording based on degree of sound periodicity

    Page(s): 841 - 843
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (262 KB)  

    Noise often appears in parts of heart sound recordings, which may also be longer than necessary for subsequent analysis. Human intervention is needed to select the subsequence with the best quality. Presented is an automated scheme for best subsequence selection to obviate such human intervention. The scheme is based on the finding that heart sound signals with less random noise contamination have a greater degree of periodicity. Both simulations and experiments validate the scheme. View full abstract»

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  • Kretschman configuration surface plasmon resonance imaging using prism sheet

    Page(s): 843 - 844
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (338 KB)  

    A prism sheet (PS) based surface plasmon resonance imaging (SPRI) system with features of Kretschman configuration is proposed. The PS contains lots of stripe-type micro-prisms positioned on the surface of the base material, being able to replace the bulky prism commonly used in existing SPRI and thus provide a more integrated form. Compared to the conventional Kretschman SPRI, the proposed SPRI uses a gold-deposited PS where prism and gold film are fully integrated on a single biochip in all-in-one to make it possible to remove the necessity of a complicated prism-coupling procedure. View full abstract»

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  • On-chip patch-clamp sensor for solid-state nanopore applications

    Page(s): 844 - 846
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (206 KB)  

    An integrated low-noise patch-clamp sensor is implemented for single-molecule DNA analysis using a solid-state nanopore. By adopting an instrumentation amplifier and a compensation switch for the headstage, the input-offset voltage and the deleterious effects of input parasitic capacitances are minimised. This high-sensitivity sensor amplifier was fabricated in a 0.35 μm CMOS process and tested with the solid-state nanopore also developed. View full abstract»

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  • Efficient iterative design of modified DFT filter banks

    Page(s): 846 - 847
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (157 KB)  

    An iterative algorithm based on the Lagrange multiplier method is presented for designing modified discrete Fourier transform (MDFT) filter banks with perfect reconstruction (PR). The dominant work at each iteration is to solve a system of linear equations involving a symmetric block matrix. By exploiting its special structure, the block matrix is factored into the product of lower and upper triangular matrices, thus leading to improved efficiency. The main benefit of the proposed scheme is that it allows the efficient design of PR MDFT filter banks with a large number of channels and/or long prototype filters. View full abstract»

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  • High-efficiency concurrent dual-band class-F and inverse class-F power amplifier

    Page(s): 847 - 849
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (283 KB)  

    A high-efficiency concurrent dual-mode dual-band power amplifier is presented. It simultaneously operates at class-F mode for one band and at inverse class-F mode for the other band. With this mode assignment method, the conflict in harmonic impedance control for concurrent dual-band applications is avoided. Experimental results show a high performance of more than 80% peaking power added efficiency with 40.6 and 41.8 dBm output power in the sampled bands of 0.8 and 1.25 GHz, respectively. View full abstract»

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  • Mitigation of noise coupling on RF cable using electromagnetic bandgap structures

    Page(s): 849 - 850
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (242 KB)  

    Noise coupling to radio frequency (RF) cable in laptop computers deteriorates the receiving sensitivity of wireless local area network (WLAN) operation. Proposed originally is a concept for reducing noise propagation along RF cable using electromagnetic bandgap (EBG) structures. The proposed EBG structure applied on RF cable allows achieving more than 20 dB noise suppression within the frequency range of WLAN application. View full abstract»

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  • Adaptive online solder joint inspection algorithm based on incremental clustering

    Page(s): 850 - 851
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (133 KB)  

    An incremental cluster based adaptive online solder joint inspection algorithm is proposed and demonstrated. First, the framework of an intelligent automated optical inspection (AOI) system is designed. Then, the initial solder joint classifier is established with the clustering algorithm. Finally, with a new incremental clustering algorithm, the AOI system can automatically adjust inspection parameters according to the feedback from the repair station. Experiments have shown that the proposed algorithm has a high inspection accuracy, and it is adaptive to environmental changes. View full abstract»

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  • Biohashing applied to orientation-based minutia descriptor for secure fingerprint authentication system

    Page(s): 851 - 853
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (66 KB)  

    Biometric recognition systems are now commonplace. Although such systems have improved security, they are vulnerable to a number of threats, including direct attacks to the sensor. It is proposed to couple a well-known orientation-based minutia descriptor with biohashing for more secure fingerprint authentication. Extensive experiments conducted over all four FVC2002 fingerprint databases show the effectiveness of the proposed approach. Also discussed is the problem of fake fingerprint reconstruction from the minutiae set. View full abstract»

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  • Golay kernel 10 decomposition

    Page(s): 853 - 855
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (93 KB)  

    The efficient Golay correlator for complementary sequences of length 2N has been known since 1991. Its computational efficiency gain compared to direct correlator implementation is comparable to the gain of FFT over DFT implementation. It was used in many applications, the most significant being the RACH preamble in the 3G wireless standard. Presented is a similar correlator for Golay complementary kernels of length 10. This correlator has four stages (building blocks) very similar to the stages of the correlator for Golay sequences of length 2N. It is shown how kernel 10 building blocks can be combined with kernel 2 building blocks to build an efficient correlator of length 2N × 10M. This allows the use of Golay sequences in applications that require a wider range of possible lengths and there is a wider range of autocorrelation functions to choose from. The theoretical importance of this result is that it shows that the kernel sequences (10, 20 and 26) have an internal structure which can lead to further theoretical results. View full abstract»

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  • Charge pump controller for grounded piezoelectric actuators used in precise positioning

    Page(s): 855 - 856
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (163 KB)  

    A charge pump controller adapted for grounded piezoelectric loads is proposed. By transferring charge packets into the piezoelectric actuator step by step, the actuator deforms with much less hysteresis and ultra-high resolution. Compared with voltage drive, the actuator hysteresis is reduced by 71-83- over a frequency range of 0.01-0.1-Hz. View full abstract»

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  • 2.5 Gbit/s duobinary signalling with narrow bandwidth 0.625 terahertz source

    Page(s): 856 - 858
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (224 KB)  

    Following the field's general trend to enhance system transport capacity by increasing the formats' carrier frequencies and payloads, a novel approach is reported for 2.5'Gbit/s signalling at a carrier frequency of 625'GHz. Duobinary baseband modulation on the transmitter side generates a signal with a sufficiently narrow spectral bandwidth to pass an upconverting frequency multiplier chain. Power, bit error rate, and signal-to-noise ratio measurements on the receiver side describe the signal performance. View full abstract»

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  • Fourth-order tri-band bandpass filter using square ring loaded resonators

    Page(s): 858 - 859
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (270 KB)  

    A tri-band bandpass filter (BPF) using a novel square ring loaded resonator (SRLR) is presented. The SRLR can generate a tri-band response by tuning its geometric parameters. Moreover, it can build the high-order tri-band BPFs using the proposed resonators because of the sufficient coupling between adjacent resonators. A fourth-order Chebyshev tri-band BPF centred at 2.4, 3.5 and 5.2 GHz is designed and fabricated. Measurement results agree well with the full-wave EM simulated results. View full abstract»

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  • UWB Gilbert downconverter with lumped-distributed phase-inverter rat-race coupler based on Chebyshev band-broadening technique

    Page(s): 859 - 861
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (250 KB)  

    A broadband Gilbert downconverter with a miniature phase-inverter rat-race coupler is demonstrated using 0.35μm SiGe BiCMOS technology. By lumped-distributed and band-broadening techniques, a large shrinkage ratio with wide bandwidth of Chebyshev response can be simultaneously attained in the spiral-shape coplanar-stripline phase-inverter rat-race coupler. The area of the demonstrated lumped-distributed phase-inverter rat-race coupler is 0.65 ×0.65μmm2 and the experimental bandwidth ranging from 2.5 to 12.5 GHz is large enough to cover the UWB bandwidth. As a result, a broadband Gilbert downconverter with the proposed coupler achieves a conversion gain of 11-12 dB, IP1dB of -11-dBm, IIP3 of -1-dBm and noise figure of 16-dB from 3 to 11-GHz. View full abstract»

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  • Compact spiral folded spurline for low-frequency applications

    Page(s): 861 - 862
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (224 KB)  

    A compact spurline design using spiral folding of the resonator is proposed. Length reduction of up to 83% is achieved making the technique useful for lower microwave frequencies. One-section spurline bandstop filters of both conventional and the new design with a centre frequency of 600%MHz have been tested and compared. There is satisfactory agreement between the performance of the new and the conventional designs. View full abstract»

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  • Compact wide-stopband lowpass filter using stepped impedance hairpin resonator with radial stubs

    Page(s): 862 - 863
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (243 KB)  

    A compact lowpass filter using a stepped impedance hairpin resonator is presented. To achieve wide stopband rejection, radial stubs were introduced. The new lowpass filter has been analysed, simulated and fabricated. Measured results are in good agreement with the electromagnetic simulation, and the circuit only occupies 0.08λg ×0.08λg. View full abstract»

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  • Low-loss AlInN/GaN microwave switch

    Page(s): 863 - 865
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (200 KB)  

    A report is presented on the first low-loss monolithic microwave integrated circuit switch using AlInN/GaN heterostructure field effect transistors. Owing to significantly lower sheet resistance compared to the conventional AlGaN/GaN heterostructure (215 against 280 Q/□), and lower contact resistance (0.27 against 0.5 Ω×mm), the microwave switch based on AlInN/GaN shows lower insertion loss (0.8 against 0.9 dB at 6 GHz) and higher isolation (40 against 35 dB at 6 GHz). The achieved performance compares favourably or exceeds published results for this frequency range; even better performance can be achieved considering ultimate parameters for AlInN/GaN heterostructures. View full abstract»

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  • Electronic dispersion precompensation for 10.709 Gbit/s NRZ-OOK using InP and LiNbO3 Mach-Zehnder modulators

    Page(s): 865 - 867
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (174 KB)  

    It is shown that electronic precompensation using InP and LiNbO3 dual-drive Mach-Zehnder modulators effectively reduces the degradation caused by chromatic dispersion for 10.709 Gbit/s on-off-keying modulation. Transmission results for a recirculating loop experiment with nonzero dispersion shifted fibre and a straight-line experiment with non-dispersion-shifted fibre achieve a dispersion tolerance of about 4 ns/nm with precompensation. View full abstract»

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  • Improved modulation speed of LED visible light communication system integrated to main electricity network

    Page(s): 867 - 868
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (221 KB)  

    In addition to the illumination purpose, using a light-emitting diode (LED) for indoor optical wireless communication has attracted much attention recently. Proposed and demonstrated is the use of a simple on-off keying (OOK) predistortion scheme together with a simple first-order resistance-capacitance equalisation circuit to increase the modulation speed of a white-light high-brightness LED (HB-LED). Optical filtering and complicated modulation formats are not required. Since only OOK modulation is used, the signal modulation and detection are very simple. Also are compared the different combinations of the system designs. By using first-order equalisation together with a predistortion, a bit-error rate of -10-10 at 10 Mbit/s can be easily achieved when using the 1 MHz bandwidth phosphor-based white HB-LED. 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