IEICE Communications Express
Online ISSN : 2187-0136
ISSN-L : 2187-0136
12 巻, 6 号
選択された号の論文の19件中1~19を表示しています
Special Cluster in Antennas and Propagation Technologies in Conjunction with Main Topics of ISAP2022
  • Mitoshi Fujimoto
    原稿種別: FOREWORD
    2023 年 12 巻 6 号 p. 254
    発行日: 2023/06/01
    公開日: 2023/06/01
    ジャーナル フリー
  • Kazuki Shintani, Satoru Shimizu, Koudai Nagatomo, Hisato Iwai, Shinsuk ...
    原稿種別: LETTER
    専門分野: Sensing
    2023 年 12 巻 6 号 p. 255-259
    発行日: 2023/06/01
    公開日: 2023/06/01
    [早期公開] 公開日: 2023/01/13
    ジャーナル フリー

    We investigated a proximity sensor technique based on changes of an antenna’s characteristics when objects such as human bodies are near the antenna. Conventionally, the difference of the return loss (DRL) has been the detection metric used for this method to detect the presence of a human body. Although the ability to detect both the presence and the distance to the body is desirable, the DRL is difficult to use for distance detection. Here, we consider a new detection metric for distance detection: the distance of the complex reflection coefficient (DRC). Finite-difference time-domain analyses and measurements were conducted to demonstrate the validity of this metric for distance detection.

  • Yuanfeng She, Sayaka Matsukawa
    原稿種別: LETTER
    専門分野: Antennas and Propagation
    2023 年 12 巻 6 号 p. 260-264
    発行日: 2023/06/01
    公開日: 2023/06/01
    [早期公開] 公開日: 2023/03/03
    ジャーナル フリー

    This paper introduces a simple position tracking system using image processing technology to measure the uncertainty caused by antenna misalignment in the extrapolation method. The antenna alignment is tracked using a camera in the extrapolation process. The uncertainty caused by misalignment can be quantitatively evaluated in the measurement. By the single-antenna extrapolation method, the expanded uncertainty (k=2) of the DRGH was estimated to be from 0.63 to 0.85 dB over a frequency range from 1 to 18 GHz.

  • Xiaotong Li, Hiroyasu Sato, Yosei Shibata, Takahiro Ishinabe, Hideo Fu ...
    原稿種別: LETTER
    専門分野: Antennas and Propagation
    2023 年 12 巻 6 号 p. 265-270
    発行日: 2023/06/01
    公開日: 2023/06/01
    [早期公開] 公開日: 2023/03/03
    ジャーナル フリー

    In this Letter, a reconfigurable reflectarray (RA) based on liquid crystal (LC) electric controlling property at Ka band is presented. The innovation focuses on measuring the phase steering ability of the whole LC RA with a structure of 4-finger under plane wave incidence and application on the actual scene, which can steer scattering wave to blind spots, not just play a role of EM launcher, but also an relay. Results show the LC RA can steer phase continuously to 213° with bias voltages and beam steering to different directions and different areas are achieved. This work introduces a LC RA as Reconfigurable Intelligent Surface (RIS) that can steer scattered beam to increase receiving power at spot, which can be an application of RIS on wireless communication.

  • Riku Takahashi, Kosuke Shibata, Anirban Ghosh, Minseok Kim
    原稿種別: LETTER
    専門分野: Antennas and Propagation
    2023 年 12 巻 6 号 p. 271-276
    発行日: 2023/06/01
    公開日: 2023/06/01
    [早期公開] 公開日: 2023/03/03
    ジャーナル フリー

    In recent years, there has been a spurt of activities to explore the terahertz (THz) band comprising frequencies above 100 GHz to support high data rates and low latency applications. In this light, the current study presents an overview of a novel in-house channel sounder operating at 300 GHz followed by elaboration of a high-resolution double-directional channel measurement performed in an office environment. The letter validates the sounder, wherein the measurement accuracy is assessed by comparing the results from the campaign and ray-tracing (RT) simulation. The measurement system is expected to contribute to the advancement of THz communications research.

  • Shuang Ji, Jiro Hirokawa, Takashi Tomura, Hirobumi Saito
    原稿種別: LETTER
    専門分野: Antennas and Propagation
    2023 年 12 巻 6 号 p. 277-281
    発行日: 2023/06/01
    公開日: 2023/06/01
    [早期公開] 公開日: 2023/03/03
    ジャーナル フリー

    This letter proposes a design of an X-band multi-layered all-metallic slot array antenna with gratings loaded between parallel plates. Unlike the conventional structure with gratings loaded in parallel to the polarization direction to eliminate detrimental resonance in a 2×2-slot subarray, this design loads the gratings perpendicular to the polarization direction. Furthermore, short stubs along the polarization direction are proved necessary to facilitate the good performance of the subarray. The proposed 16×8-slot array demonstrates low-reflection, wide-band and high-efficiency characteristics in measurements.

  • Uuganbayar Purevdorj, Ryuji Kuse, Takeshi Fukusako
    原稿種別: LETTER
    専門分野: Antennas and Propagation
    2023 年 12 巻 6 号 p. 282-287
    発行日: 2023/06/01
    公開日: 2023/06/01
    [早期公開] 公開日: 2023/03/03
    ジャーナル フリー

    This letter describes a wideband circularly polarized (CP) array antenna with 2 × 2 alignment of sequentially rotated CP patch elements. Each patch element has a diamond-shaped artificial ground structure (DAGS), which extend the 3-dB axial ratio (AR) bandwidth of a CP antenna, and the patch elements in the array are fed with relative phases of 0°, 90°, 180° and 270°. The main purpose of this work is to show the potential of the 3-dB AR bandwidth by a combination of the DAGS and the sequential rotation technique considering the effect of coupling with neighboring elements. The proposed array antenna achieves an overlapped bandwidth of 74.9% (4.30 GHz-9.45 GHz) with the -10-dB |S11|, 3-dB AR and 3-dB gain characteristics. Also, the 3-dB gain bandwidth of this antenna is 54.65% at 5.0 GHz-8.76 GHz. Furthermore, the cross-polarization is sufficiently suppressed in the main beam of 14 dBic. As a result, it is shown that the patch antenna with DAGS can be applied to sequential array technology with sufficiently low coupling, and the AR bandwidth can be broadened.

  • Nobuyasu Takemura
    原稿種別: LETTER
    専門分野: Antennas and Propagation
    2023 年 12 巻 6 号 p. 288-293
    発行日: 2023/06/01
    公開日: 2023/06/01
    [早期公開] 公開日: 2023/03/06
    ジャーナル フリー

    In this paper, the author described the examination results of interference suppression between mobile terminals using space diversity and Eigen-beamforming techniques of mobile terminals for millimeter-wave full-duplex MIMO systems. The system studied a method of simultaneously transmitting and receiving a signal on the same frequency band in uplink and downlink between a base station and a mobile terminal. Applying the space diversity technique to the mobile terminal when performing Eigen beamforming achieved further interference suppression. A ray-tracing simulation of millimeter-wave radio propagation in an outdoor environment confirmed this method’s effectiveness.

  • Masayuki Miyashita, Ayumu Yabuki, Toshiki Hozen, Kazuma Tomimoto, Ryo ...
    原稿種別: LETTER
    専門分野: Antennas and Propagation
    2023 年 12 巻 6 号 p. 294-299
    発行日: 2023/06/01
    公開日: 2023/06/01
    [早期公開] 公開日: 2023/03/15
    ジャーナル フリー

    As the 6th generation mobile communication system is expected to use the terahertz wave band, it is essential to clarify the human body blocking and scattering characteristics as many small cells for indoor and outdoor use will be needed. In addition, since it is important to use high-gain antennas with orthogonal polarization to realize efficient MIMO transmission, it is necessary to clarify the polarization characteristics of human body blocking and scattering. Experiments conducted to investigate human body scattering in the terahertz wave band show that the scattering characteristics are polarization dependent.

  • Takahiro Tomie, Satoshi Suyama, Koshiro Kitao, Mitsuki Nakamura
    原稿種別: LETTER
    専門分野: Antennas and Propagation
    2023 年 12 巻 6 号 p. 300-304
    発行日: 2023/06/01
    公開日: 2023/06/01
    [早期公開] 公開日: 2023/03/27
    ジャーナル フリー

    In this letter, a method for path loss prediction in outdoor urban environments based on computer graphics technologies is presented. Each wall of buildings in an evaluation area is assigned to a different RGB color. We create two types of color images that are viewed from a transmission point (Tx) and receiving points (Rxs). By analyzing and comparing the colors of these images, the visible colors existed in both images corresponding to the single scattering walls are detected all at once. The numbers of pixels of the visible colors are used to calculate received powers of the single scattering waves. The average and RMSE of difference between predicted path loss results and measurement results are small with -0.5dB and 7.6dB, respectively. The computation time is extremely short.

  • Hiroto Yonawa, Hisato Iwai, Shinsuke Ibi
    原稿種別: LETTER
    専門分野: Wireless Communication Technologies
    2023 年 12 巻 6 号 p. 305-310
    発行日: 2023/06/01
    公開日: 2023/06/01
    [早期公開] 公開日: 2023/03/29
    ジャーナル フリー

    Spatially selective modulation (SSM) is a physical layer security technique that uses multiple transmitting antennas and a single receiving antenna. SSM allows only the legitimate receiver to receive the desired modulated signal correctly because of the location dependence of a multipath channel. Previous SSM studies have been statistically conducted using the Rayleigh fading channel. Here, we evaluated the secret transmission performance of SSM using ray-tracing, which is a deterministic propagation model. We assumed an indoor environment in the evaluation. We found that increasing the separation between the transmitting antenna elements improved the secret transmission performance of SSM in the assumed environment.

  • Eisuke Nishiyama, Shuto Suenaga, Ichihiko Toyoda
    原稿種別: LETTER
    専門分野: Antennas and Propagation
    2023 年 12 巻 6 号 p. 311-315
    発行日: 2023/06/01
    公開日: 2023/06/01
    [早期公開] 公開日: 2023/04/28
    ジャーナル フリー

    In this paper, a novel dual-polarized microstrip array antenna is proposed and its characterisitics are investigated. In general, dual-polarized array antennas have complicated antenna element excitation methods and feeding circuits. Both-sided microwave-integrated circuit (MIC) technology such as a magic-T can simplify the antenna structure. As the proposed dual-polarized microstrip array antenna integrates magic-Ts, array elements and two orthogonal feed circuits can be arrenged on a single-layer substrate. The characteristics of the antenna are simulated and the results are compared with experimental values.

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