With a ten-year horizon from concept to reality, it is time now to start thinking about what will the sixth-generation(6G) mobile communications be on the eve of the fifth-generation(5G) deployment. To pave the way fo...With a ten-year horizon from concept to reality, it is time now to start thinking about what will the sixth-generation(6G) mobile communications be on the eve of the fifth-generation(5G) deployment. To pave the way for the development of 6G and beyond, we provide 6G visions in this paper. We first introduce the state-of-the-art technologies in 5G and indicate the necessity to study 6G. By taking the current and emerging development of wireless communications into consideration, we envision 6G to include three major aspects, namely, mobile ultra-broadband, super Internet-of-Things(IoT), and artificial intelligence(AI). Then, we review key technologies to realize each aspect. In particular, teraherz(THz) communications can be used to support mobile ultra-broadband, symbiotic radio and satellite-assisted communications can be used to achieve super IoT, and machine learning techniques are promising candidates for AI. For each technology, we provide the basic principle, key challenges, and state-of-the-art approaches and solutions.展开更多
We observe enhanced terahertz (THz) radiation generated from a Si3N4 film-coated GaAs photoconductive dipole antenna. Compared to an uncoated antenna with identical electrode geometry and optical excitation power, the...We observe enhanced terahertz (THz) radiation generated from a Si3N4 film-coated GaAs photoconductive dipole antenna. Compared to an uncoated antenna with identical electrode geometry and optical excitation power, the Si3N4 film-coated antenna has a higher effective DC resistance and larger breakdown voltage. As a result, the peak amplitude of generated THz radiation is significantly enhanced due to the Si3N4 film-coated layer.展开更多
太赫兹时域光谱(Terahertz time domain spectroscopyr,THz-TDS)是基于飞秒超快激光的远红外波段光谱测量新技术。我们利用该技术对苯甲酸及其单甲基取代物进行测量,得到了它们在0.1-2.0THz波段的吸收谱图。4种物质的吸收谱有明显的特征...太赫兹时域光谱(Terahertz time domain spectroscopyr,THz-TDS)是基于飞秒超快激光的远红外波段光谱测量新技术。我们利用该技术对苯甲酸及其单甲基取代物进行测量,得到了它们在0.1-2.0THz波段的吸收谱图。4种物质的吸收谱有明显的特征,可以将这几种化合物区分开来,这表明THz-TDS技术可以分辨化合物结构上的微小差异,可以应用于物质检测与分析。展开更多
基金supported in part by National Natural Science Foundation of China under Grants 61631005, 61801101, U1801261, and 61571100
文摘With a ten-year horizon from concept to reality, it is time now to start thinking about what will the sixth-generation(6G) mobile communications be on the eve of the fifth-generation(5G) deployment. To pave the way for the development of 6G and beyond, we provide 6G visions in this paper. We first introduce the state-of-the-art technologies in 5G and indicate the necessity to study 6G. By taking the current and emerging development of wireless communications into consideration, we envision 6G to include three major aspects, namely, mobile ultra-broadband, super Internet-of-Things(IoT), and artificial intelligence(AI). Then, we review key technologies to realize each aspect. In particular, teraherz(THz) communications can be used to support mobile ultra-broadband, symbiotic radio and satellite-assisted communications can be used to achieve super IoT, and machine learning techniques are promising candidates for AI. For each technology, we provide the basic principle, key challenges, and state-of-the-art approaches and solutions.
基金This work is supported by the National Natural Science Foundation of China (No. 50077017) and the U.S.National Science Foundation. X.-C. Zhang is the author to whom the correspondence should be addressed,
文摘We observe enhanced terahertz (THz) radiation generated from a Si3N4 film-coated GaAs photoconductive dipole antenna. Compared to an uncoated antenna with identical electrode geometry and optical excitation power, the Si3N4 film-coated antenna has a higher effective DC resistance and larger breakdown voltage. As a result, the peak amplitude of generated THz radiation is significantly enhanced due to the Si3N4 film-coated layer.
文摘太赫兹时域光谱(Terahertz time domain spectroscopyr,THz-TDS)是基于飞秒超快激光的远红外波段光谱测量新技术。我们利用该技术对苯甲酸及其单甲基取代物进行测量,得到了它们在0.1-2.0THz波段的吸收谱图。4种物质的吸收谱有明显的特征,可以将这几种化合物区分开来,这表明THz-TDS技术可以分辨化合物结构上的微小差异,可以应用于物质检测与分析。
