2018 Fiscal Year Annual Research Report
| Project/Area Number |
18F17368
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| Research Institution | National Institute of Information and Communications Technology |
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Principal Investigator |
渡邊 聡一 国立研究開発法人情報通信研究機構, 電磁波研究所電磁環境研究室, 研究マネージャー (30358957)
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| Co-Investigator(Kenkyū-buntansha) |
LE DINH THANH 国立研究開発法人情報通信研究機構, 電磁波研究所電磁環境研究室, 外国人特別研究員
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| Project Period (FY) |
2018-04-25 – 2020-03-31
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| Keywords | Electromagnetic field / Human exposure / Compliance test / Specific absorption rate / E-field measurement / K-order model / multi-input multi-output (MIMO) / Phased array antenna |
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| Outline of Annual Research Achievements |
This research aims to address effective measurement techniques to determine the maximum specific absorption rate (SAR) and/or electric field of multiple-antenna transmitters for the compliance tests. Novel estimation techniques with K-order expressions for fast and highly accurate evaluations have been developed in our studies. From our study during last year, it was confirmed that our proposed techniques using K-order estimations can provide precisely estimated SAR and significantly reduce the estimation errors (i.e. the deviation between the estimated and calculated/measured SAR/electric fields). For example, investigations on the maximum electric fields of two antennas operating at 2.5 GHz in an ordinary room show that the maximum estimation errors caused by conventional estimations can be as high as 10%, which is suppressed to below 0.24%, and 0.02% by 2- and 3-order estimations, respectively.
In addition, we have also investigated several related issues of human-body exposures to electromagnetic fields such as the effects of user’s hands as well as some practical issues and measurement uncertainty in SAR measurements for multiple-antenna transmitters. As a result, we have published 1 journal paper in the IEEE Transactions on Antennas and Propagation (a top journal in the research field), 5 conference papers in international conferences and 3 technical reports in national conferences and meetings.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
Generally, the research is well conducted as planned. At current progress of the research, we have achieved several significant results, which are expected at the beginning of the project as main contributions (including the developments of new estimation techniques using K-order models in both theoretical analysis and experimental validations, several academic publications in well-known national and international conferences and journals). In the remained time of the project, we will firmly follow the research plan to complete all objectives of the project. Thanks to significant achievements up to present, we can confidently confirm that the project will be carried out successfully.
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| Strategy for Future Research Activity |
From now until the end of the project and the beyond, we will work hard to expand the developments of the proposed techniques. We schedule to conduct several experimental validations of the proposed techniques in the mm Wave bands, which are essential for 5G systems as well as other promising applications such as short-range radars for automotive cars or drones. We will also contribute the results of this project to national and international standards in SAR/electric field measurements for multiple-antenna transmitters. Practical application notes for utilizing the proposed measurement techniques for currently available SAR measurement systems will also be developed. In addition, based on the results of this project, we will try to address new challenges in SAR measurements for new wireless technologies such as massive MIMO systems or wireless power transmitting systems. Finally, the results of this project will be summarized and presented in several international conference meetings for further discussions, developments, and implementations.
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