Research on antennas for microwave OAM communication

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K06337
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Communication/Network engineering
• Research Institution: The University of Electro-Communications
• Principal Investigator: Saitou Akira 電気通信大学, 先端ワイヤレス・コミュニケーション研究センター, 客員教授 (80536920)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 情報通信工学 / アンテナ理論 / MIMO / 軌道角運動量

Outline of Final Research Achievements

Physical mechanism of OAM (orbital Angular Momentum) communication characteristics has been analyzed for the generation and reception of OAM waves. Appropriate configurations of a loop antenna were clarified to radiate an approximately unique OAM mode. Four-element loop antenna arrays with the configurations were fabricated. For short-range OAM communication at a 5 GHz band for the distance of 3 cm, the measured signal to interference ratios were more than 20 dB, which is promising result for four-channel MIMO communication. For more practical estimate for the communication, two-channel 64 QAM communication was shown to be realized without the MIMO signal processing to compensate the interference. For long-range OAM communication at a 5 GHz band for the distance of 90 cm, paraboloids were utilized to suppress the expansion of the OAM waves. Measured signal to interference ratio was better than 18 dB.

Free Research Field

マイクロ波工学

Academic Significance and Societal Importance of the Research Achievements

これまではあまり使用されることになかった軌道角運動量を有するOAM波動の物理的な生成方法を明確にした。OAM波動の直交性を活用し、信号処理を行わなくても伝送路多重通信が可能なことを示した。OAM通信は、周波数が同じでもOAM波の空間分布の違いで伝送路多重を行うもので、貴重で有限な資源である周波数の利用効率が飛躍的に向上される。さらに本提案の方法では、OAM波がアンテナ単独で放射できることからシンプルなシステムが実現できると期待される。また通信以外に、OAM波を用いたレーダ、センサへの応用があり、シンプルなOAM波生成方法を生かして、新たな特徴をもつセンサへの展開も期待できる。