IEICE Electronics Express
Online ISSN : 1349-2543
ISSN-L : 1349-2543
Volume 20, Issue 5
Displaying 1-9 of 9 articles from this issue
LETTER
  • Weifeng Liu, Tianxiao Zhang, Hanchen Zhang, Hualian Tang, Li Zhang
    Article type: LETTER
    Subject area: Integrated circuits
    2023 Volume 20 Issue 5 Pages 20220529
    Published: March 10, 2023
    Released on J-STAGE: March 10, 2023
    Advance online publication: January 25, 2023
    JOURNAL FREE ACCESS

    Due to the appearance of huge glitch while using traditional Dynamic Element Matching (DEM) in data converters, different kinds of glitch-reduce structures are designed into DEM. However, most of these structures will work with high complexity. Based on random-rotation-binary-weighted selection (RRBS), this paper presents a novel low complexity glitch-reduced DEM algorithm, which can greatly reduce mismatch. The proposed DEM constructs glitch-reduce structure through data selector and comparator, so the complexity is reduced through using less components. As a result, the glitch-reduced DEM increases spurious free dynamic range (SFDR) to 92.47dB at 7.6MHz. Moreover, compared with conventional RRBS, glitch-reduced DEM makes the glitch reduce by 49% with low complexity in a 12-bit digital-to-analog converter (DAC).

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  • Siyi Yang, Li Xu, Junhui Yin, Hao Wang, Bin Li
    Article type: LETTER
    Subject area: Electromagnetic theory
    2023 Volume 20 Issue 5 Pages 20220540
    Published: March 10, 2023
    Released on J-STAGE: March 10, 2023
    Advance online publication: January 19, 2023
    JOURNAL FREE ACCESS

    Accurate simulation of electrostatic field in electronic devices is very important to improve their performance. When the traditional finite element method is used to analyze the electrostatic field of large and complex structures, the calculation speed is slow and the computing resources are greatly consumed. Therefore, in this paper, we investigate electrostatic analysis with a non-overlapping domain decomposition method based on the scalar finite element method under a novel transmission condition. In order to improve the efficiency of matrix solving and reduce the memory consumption, the block Jacobi preconditioner is introduced. In addition, the multifrontal block incomplete Cholesky preconditioner is utilized to further improve the computational performance based on the block Jacobi preconditioner. Several numerical examples are simulated and compared with the analytical solutions and the commercial software Maxwell 3D. The results demonstrate the accuracy and efficiency of the proposed domain decomposition method.

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  • Zheng Li, Zixin Chen, Qiaoyu Wang, Junqing Liu, Jian Pang, Atsushi Shi ...
    Article type: LETTER
    Subject area: Integrated circuits
    2023 Volume 20 Issue 5 Pages 20220558
    Published: March 10, 2023
    Released on J-STAGE: March 10, 2023
    Advance online publication: February 13, 2023
    JOURNAL FREE ACCESS

    In this letter, a 41-GHz Doherty power amplifier (PA) in standard 65nm CMOS technology is introduced for 5G New Radio (NR) applications. The proposed PA implements the transformer-based parallel-combined Doherty structure to enhance the power-added efficiency (PAE). A tunable 90-deg hybrid coupler is proposed for output phase compensation. This work achieves a saturated output power (Psat) of 19.4dBm and an OP1dB of 18.6dBm at 41.5GHz under a 1-V power supply. The peak PAE and the PAE at 6-dB output power back-off (PBO) are 30.4% and 19.2%, respectively. This work also supports single-carrier mode (SC-mode) 400-MSymbols/s 256QAM and OFDMA-mode 400-MHz 256QAM. The core chip area is 0.22 mm2 with a static power consumption of 76mW.

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  • Liang Zhao, Xusheng Tang, Xinyi Chu, Xiaoxiao Feng, Youming Zhang
    Article type: LETTER
    Subject area: Integrated circuits
    2023 Volume 20 Issue 5 Pages 20220560
    Published: March 10, 2023
    Released on J-STAGE: March 10, 2023
    Advance online publication: February 07, 2023
    JOURNAL FREE ACCESS

    This paper presents an 11-15GHz MMIC multifunction chip (MFC) with phase and amplitude control. The chip is based on the common-leg structure and comprises a phase shifter (PS), attenuator (ATT), T/R switch, gain compensation amplifiers (AMPs), driver stage AMPs and parallel control circuits. In the 11-15GHz bandwidth, measurements show that the gain and saturation power (Psat) are higher than 21.5dB and 26.5dBm, while the efficiency is more than 30% in TX mode. In RX mode, the small signal gain is more than 10.2dB, the NF is less than 9.8dB, and output 1dB power (OP1dB) is more than 8.5dBm. The measured minimum RMS phase and amplitude errors are 1.7° and 0.45dB, respectively.

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  • Naoya Hieda, Akito Iguchi, Yasuhide Tsuji, Keita Morimoto, Tatsuya Kas ...
    Article type: LETTER
    Subject area: Electromagnetic theory
    2023 Volume 20 Issue 5 Pages 20230012
    Published: March 10, 2023
    Released on J-STAGE: March 10, 2023
    Advance online publication: January 24, 2023
    JOURNAL FREE ACCESS

    In recent years, optimization technique has attracted a lot of attention to develop high performance electromagnetic devices and various kinds of design strategies have been reported. Among them, topology optimization method has potential to develop innovative devices. In this paper, the function expansion based topology optimization method, which has been developed for design of photonic devices, is extended to be applied to design of nonradiative dielectric waveguide (NRD guide) devices. In the optimal design of NRD guide devices, solution search sometimes tends to fall into local minimum compared with the design of photonic devices. Therefore, we develop a novel hybrid optimization method combining harmony search which is one of the evolutionary algorithm and gradient method using adjoint variable method for robust and efficient design of NRD guide devices.

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  • Taisei Arima, Shigeru Hidaka, Ryosuke Watanabe, Tomoya Akasaka, Atsush ...
    Article type: LETTER
    Subject area: Power devices and circuits
    2023 Volume 20 Issue 5 Pages 20230014
    Published: March 10, 2023
    Released on J-STAGE: March 10, 2023
    Advance online publication: February 06, 2023
    JOURNAL FREE ACCESS

    This paper proposes a novel trimming method of thin-film resistors dedicated to the power modules. Thin-film resistors are utilized for applications including snubber circuits which avoids unwanted ringing appearing in the output voltage of power transistors. Our previous works have revealed that the applicable voltage of a NiCr thin-film resistor is thermally limited, and then the indispensable trimming process affects the degree of temperature rise in use. In this paper, we first formulate the relationship between the target resistance value and the trim dimensions using machine learning. With the obtained equation, we propose a new trimming method, which enables the trimmed pattern to reduce the variability of the maximum temperature rise. The experimental results show that the proposed trimming method can suppress the estimated range of the maximum temperature from 619K to 179K.

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  • Yu Yao, Yu Shao, Jiliang Zhang, Jie Zhang
    Article type: LETTER
    Subject area: Microwave and millimeter wave devices, circuits, and modules
    2023 Volume 20 Issue 5 Pages 20230022
    Published: March 10, 2023
    Released on J-STAGE: March 10, 2023
    Advance online publication: February 13, 2023
    JOURNAL FREE ACCESS

    An optical transparent antenna using indium tin oxide (ITO) for ultra-wideband (UWB) multiple-input multiple-output (MIMO) applications is proposed. The ultrathin ITO film is coated on a 67×67mm2 glass substrate and over 85% transparency is achieved. The antenna consists of four coplanar waveguide (CPW)-fed antenna elements with rotationally symmetric placement. The adjacent elements are placed orthogonally to produce dual polarisation and reduce coupling. The MIMO antenna operates from 1.5 to 11GHz which covers the UWB applications. The coupling between the elements is less than -23dB. Mean effective gain (MEG), envelope correlation coefficient (ECC) and diversity gain (DG) achieve excellent values which guarantee good MIMO performance. The prototype is verified and the measured results are analysed.

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  • Haitao Sun, Yan Chen, Yinke Dou
    Article type: LETTER
    Subject area: Power devices and circuits
    2023 Volume 20 Issue 5 Pages 20230024
    Published: March 10, 2023
    Released on J-STAGE: March 10, 2023
    Advance online publication: January 31, 2023
    JOURNAL FREE ACCESS

    In order to reduce the torque ripple of a switched reluctance motor in the electric vehicles, a space vector pulse width modulation (SVPWM) driving method for the switched reluctance motor (SRM) is proposed. With a ring structure, a three-phase SRM can be driven by using a standard full-bridge power converter instead of the conventional asymmetric H-bridge. Based on this type of driving topology, an SVPWM method is applied for driving the SRM. The SVPWM method is compared to the conventional SRM driving method by using the asymmetric H-bridge, the results show that the SVPWM can reduce the torque ripple in the SRM effectively. The experimental validation is also made to verify the proposed driving topology and method, of which the results match well with the simulated results.

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  • Kai Sato, Toshiki Kanamoto, Ryotaro Kudo, Koutaro Hachiya, Atsushi Kur ...
    Article type: LETTER
    Subject area: Devices, circuits and hardware for IoT and biomedical applications
    2023 Volume 20 Issue 5 Pages 20230030
    Published: March 10, 2023
    Released on J-STAGE: March 10, 2023
    Advance online publication: February 06, 2023
    JOURNAL FREE ACCESS

    This letter proposes a new method for obtaining self and mutual inductances in wireless power transfer (WPT) systems using a Bayesian neural network (BNN). Generally, inductance calculations using a field solver take a huge amount of time. Moreover, due to the complexity of WPT systems, there is no approximate equation for calculating inductances including ferrite shields. In this letter, nine structural parameters of a WPT system are experimentally used as inputs. The experimental results demonstrate that inductances obtained by the proposed method are within 5.1% in the maximum errors and within 1.1% in the mean absolute errors. The proposed method is about 748k times faster than the field solver in the CPU time required to obtain the inductances of one structure.

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