IEICE Electronics Express
Online ISSN : 1349-2543
ISSN-L : 1349-2543
Volume 12 , Issue 4
Showing 1-9 articles out of 9 articles from the selected issue
LETTER
  • Ke Li, Biyang Wen, Yamin Xu, Jian Tan, Jing Yang, Yu Liu
    Type: LETTER
    Subject area: Electron devices, circuits, and systems
    2015 Volume 12 Issue 4 Pages 20141074
    Published: 2015
    Released: February 25, 2015
    [Advance publication] Released: January 30, 2015
    JOURNALS FREE ACCESS
    This paper proposes a novel ultra high frequency (UHF) radar system for river dynamics parameters monitoring. As compared with conventional radar system: (1) Intermediate frequency (IF) sampling mode of traditional superheterodyne receivers is replaced by the direct radio frequency (RF) band-pass sampling and orthogonal demodulation (2) Multi-channel antenna system is divided into two units, which realizes that one radar system operation obtains two-dimensional current vectors. Results of field test compared with EKZ-I current measurement at Xiantao Hydrological Station, China from August to September in 2014 are given to demonstrate the correctness and effectiveness of this system.
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  • Mingyu Wang, Yan Han, Rui Wang, Xiaopeng Liu, Jun Sun
    Type: LETTER
    Subject area: Electron devices, circuits, and systems
    2015 Volume 12 Issue 4 Pages 20141104
    Published: 2015
    Released: February 25, 2015
    [Advance publication] Released: February 05, 2015
    JOURNALS FREE ACCESS
    We present a software-hardware cooperative method for multi-projector seamless tiled display system, and it mainly consists of two steps. Firstly, an ordinary PC (Personal Computer) is used to preprocess the display system with software. Secondly, one or more hardware image processors, which are based on FPGAs (Field Programmable Gate Arrays), are used to process the source video image without the aid of computers. And an optimized algorithm is used in the method. Experimental results show that the proposed method is effective and of low cost and high performance.
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  • Chunbiao Li, Ihsan Pehlivan, Julien Clinton Sprott, Akif Akgul
    Type: LETTER
    Subject area: Electron devices, circuits, and systems
    2015 Volume 12 Issue 4 Pages 20141116
    Published: 2015
    Released: February 25, 2015
    [Advance publication] Released: February 03, 2015
    JOURNALS FREE ACCESS
    Attractor merging can exist in chaotic systems with some kind of symmetry, which makes it possible to form a four-wing attractor from a bistable system. A relatively simple such case is described, which has robust chaos varying from a pair of coexisting symmetric single-wing attractors to a double-wing butterfly attractor, and finally to a four-wing attractor. Basic dynamical characteristics of the system are demonstrated in terms of equilibria, Jacobian matrices, Lyapunov exponents, and Poincaré sections. From a broad exploration of the dynamical regions, we observe robust chaos with embedded Arnold tongues of periodicity in selected parameter regions. The chaotic system with a wing structure has four nonlinear quadratic terms, one of the coefficients of which is a hidden isolated amplitude parameter, by which one can control the amplitude of two of the variables. The corresponding chaotic circuit with an amplitude-control knob is designed and implemented, which generates a four-wing attractor with adjustable amplitude.
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  • Yuzuru Shizuku, Tetsuya Hirose, Nobutaka Kuroki, Masahiro Numa, Mitsuj ...
    Type: LETTER
    Subject area: Integrated circuits
    2015 Volume 12 Issue 4 Pages 20141157
    Published: 2015
    Released: February 25, 2015
    [Advance publication] Released: January 30, 2015
    JOURNALS FREE ACCESS
    In this paper, we present an ultra-low voltage Advanced Encryption Standard (AES) SubBytes transformation (S-BOX) circuit. The S-BOX is widely used as a basic cryptographic primitive for the secure transaction in wireless sensor networks. We employ an asynchronous circuit design technique for low-voltage operations to achieve ultra-low power dissipation. In the proposed approach, we apply a quasi-delay-insensitive (QDI) design methodology to the asynchronous S-BOX circuit to reduce the spurious transitions in combinational logics and to increase robustness against PVT variations. Measurement results in 0.18-µm CMOS process demonstrated that our asynchronous S-BOX circuit consumes only 0.99-pJ at 330-mV, which is 12% less energy than that of synchronous one. QDI asynchronous circuits in the datapath are an effective solution in the near-threshold and sub-threshold regimes.
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  • Hyukjin Chae, Ilnam Cho, Dong Ku Kim
    Type: LETTER
    Subject area: Electron devices, circuits, and systems
    2015 Volume 12 Issue 4 Pages 20141177
    Published: 2015
    Released: February 25, 2015
    [Advance publication] Released: January 30, 2015
    JOURNALS FREE ACCESS
    Power amplifier transient of LTE modem is discussed. In current LTE specification, the requirement of power amplifier transient period for LTE modem is within 40 µs. Under this requirement, non-negligible inter-carrier interference (ICI) can be observed for both of normal cyclic prefix (CP) (= 4.7 µs) and extended CP (= 16.7 µs). We analyze the ICI in terms of the transient response of power amplifier and propose ICI mitigation schemes: 1) digital pre-distortion at transmitter 2) low complexity multi-tap equalization at receiver based on the ICI analysis.
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  • Hao Wang, Zhangming Zhu
    Type: LETTER
    Subject area: Integrated circuits
    2015 Volume 12 Issue 4 Pages 20141182
    Published: 2015
    Released: February 25, 2015
    [Advance publication] Released: February 05, 2015
    JOURNALS FREE ACCESS
    A novel multi-reference capacitor switching scheme for ultra-low power successive approximation register (SAR) ADCs is proposed. By using 5 references, the proposed switching scheme only dissipates 10.6 CV2REF average energy and requires 256 unit capacitors, which are reduced by 99.2% and 87.5%, compared to the conventional structure. Besides, the common-mode voltage of the comparator input is approximately constant, which relaxes the required comparator’s performance. Behavioral simulation results demonstrate the superiority of the proposed switching scheme.
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  • Yawei Guo, Yue Wu, Dongdong Guo, Xu Cheng, Zhiyi Yu, Xiaoyang Zeng
    Type: LETTER
    Subject area: Integrated circuits
    2015 Volume 12 Issue 4 Pages 20150001
    Published: 2015
    Released: February 25, 2015
    [Advance publication] Released: January 30, 2015
    JOURNALS FREE ACCESS
    A non-binary digital calibration scheme is proposed for split-capacitor digital-to-analog converter (DAC) in successive approximation register (SAR) analog-to-digital converter (ADC). This calibration scheme improves linearity without additional analog circuits and relaxes the requirement of the comparator offset. Furthermore, it allows bigger settling error for each capacitor in MSB array in normal operation. It is utilized in the design of a 10b 50 MS/s SAR ADC in 65 nm CMOS technology with the calibration circuitry integrated. Measurement results show a peak SNDR of 56.2 dB, while consuming 0.82 mW from 1.2 V supply. The FOM is 31.1 fJ/conv.-step and the ADC occupies 0.057 mm2 active area, which proves the proposed scheme compared with our previous work without calibration.
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  • Toshifumi Moriyama, Lorenzo Poli, Paolo Rocca
    Type: LETTER
    Subject area: Electromagnetic theory
    2015 Volume 12 Issue 4 Pages 20150028
    Published: 2015
    Released: February 25, 2015
    [Advance publication] Released: January 28, 2015
    JOURNALS FREE ACCESS
    In the framework of wireless power transmission applications, the design of planar phased arrays providing maximum beam collection efficiency (i.e., maximizing the ratio between the power radiated over a target area and the total power transmitted by the array) through a sub-arrayed architecture is addressed. The degrees-of-freedom of the synthesis problem at hand (i.e., the membership of the array elements to clusters and the sub-array amplitudes) are determined by means of an excitation matching technique exploiting the knowledge of the set of independent and optimal weights providing maximum transfer efficiency. A set of representative results is reported to assess the reliability and effectiveness of the approach in yielding beam efficiency values close to the optimal ones with a limited number of sub-arrays.
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  • Yongwoon Cho, Taeseok Kim
    Type: LETTER
    Subject area: Storage technology
    2015 Volume 12 Issue 4 Pages 20150066
    Published: 2015
    Released: February 25, 2015
    [Advance publication] Released: February 03, 2015
    JOURNALS FREE ACCESS
    An efficient scheduling scheme for NCQ in SSDs is presented. Our scheme estimates the I/O service time of each command by considering the state of the buffer as well as the SSDs’ physical characteristics, and then first services the command with the shortest I/O service time. Through the trace-driven simulations, we show that the proposed scheme significantly improves the I/O performance in terms of average response time.
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