IEICE Electronics Express
Online ISSN : 1349-2543
ISSN-L : 1349-2543
Volume 16 , Issue 9
Showing 1-4 articles out of 4 articles from the selected issue
LETTER
  • Wu Chen, Li Yinghui, Liu Cong
    Type: LETTER
    Subject area: Power devices and circuits
    2019 Volume 16 Issue 9 Pages 20171066
    Published: 2019
    Released: May 10, 2019
    [Advance publication] Released: December 22, 2017
    JOURNALS FREE ACCESS

    In order to solve the problem of classic control methods in slow transient response and low anti-interference capacity, this paper proposed a dual closed-loop control scheme based on sliding mode (SM) and proportional-integral (PI) control for a three-phase rectifier. In this work, the error between id, iq and their desired value were treated as the states of the sliding mode surface, considering the control objectives of power factor and output voltage, which improved the stability and robust performance; besides, a double power reaching law was applied in the controller, which improved the dynamic performance, as well as restraining the chatter. Finally, the proposed strategy was tested in simulation and experiment compared with dual close-loop PI-PI scheme.

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  • Xin Ma, Xiaochen Chen, Li Xiao, Na Wang, Siyang Sun
    Type: LETTER
    Subject area: Microwave and millimeter-wave devices, circuits, and modules
    2019 Volume 16 Issue 9 Pages 20190119
    Published: 2019
    Released: May 10, 2019
    [Advance publication] Released: April 10, 2019
    JOURNALS FREE ACCESS

    A novel compact active BeiDou helical antenna, operating at normal mode is proposed for high-shock projectile applications. To achieve excellent impedance matching, a grounded matching stub is introduced in this design. For demonstration, a prototype with extremely compact size (22 × 22 mm) is fabricated and measured. The measured reflection coefficients below 10-dB is almost 15 MHz centered at 1268 MHz. Omni-directional radiation pattern of the proposed antenna is realized. Additionally, stable signal reception under various motion attitudes could also be proved by experiments.

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  • Ryo Manago, Kazuyuki Saito
    Type: LETTER
    Subject area: Microwave and millimeter-wave devices, circuits, and modules
    2019 Volume 16 Issue 9 Pages 20190131
    Published: 2019
    Released: May 10, 2019
    [Advance publication] Released: April 16, 2019
    JOURNALS FREE ACCESS

    In surgical devices, it is pointed out that tissues around these devices may experience thermal damage (coagulation). Therefore, evaluating the coagulated region generated by a microwave surgical device is an important issue. In this paper, we estimate the distribution of the coagulated region using numerical calculation. Then, there is a possibility that the calculated results will be affected by change to the electrical and thermal constants during heating. Therefore, the temperature dependence of the tissue was considered. As a result, it was confirmed that the coagulation width at the center of the lower blade was 0.5 mm larger than that without temperature dependence.

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  • Lamin Zhan, Yuxuan Ouyang, Guoan Wu, Baoquan Hu, Xiang Zhang
    Type: LETTER
    Subject area: Microwave and millimeter-wave devices, circuits, and modules
    2019 Volume 16 Issue 9 Pages 20190207
    Published: 2019
    Released: May 10, 2019
    [Advance publication] Released: April 16, 2019
    JOURNALS FREE ACCESS

    This letter introduces a novel on-line digital pre-distortion structure for linearizing RF power amplifier under the output impedance mismatch conditions. Unlike traditional off-line structures, the proposed structure updates its weight parameters adaptively synchronizing with the power amplifier load impedance. Furthermore, this letter analyses with a MOSFET model and proves that the output conductance of MOSFET are relevant to nonlinearity of power amplifier with variable load impedance. To verify this structure and the analysis, a simulation on MATLAB Simulink was built using a N-channel MOSFET based on Shichman-Hodges model. Proposed on-line Digital Pre-Distortion structure significantly acquired better linearity performance with variable load impedance than conventional off-line structures.

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