摘要
一、引言各种高质量异质结构材料的出现,促进了毫米波异质结三端器件和光控微波器件的发展。近几年,高温超导材料的兴起,又打开了微波器件和电路在低温(77°K)下的实际应用前景。这些都是当前微波领域的重要问题,值得重视。限于篇幅,本文只对高频异质结构中的二种器件HEMT和HBT作较为详尽的介绍,其它器件仅仅是作为问题提出。好在本文宗旨是抛砖引玉。
Atmospheric effects affecting the propagation of Millimeterwave radiation (MMW) will be considered, The most important effect is attenuation, and a summary of the work of H. J. Liebe of the U.S. National Telecommunications Administration and C. J. Gibbins of the British Rutherford Appleton Laboratory will be presented. The results of calculations of atmospheric attenuation as a function of frequency under various atmospheric conditions, including clear air,rain, fog, and snow, will be given. Measurement results will also be discussed. Based on the work of R. J. Hill and S. F. Clifford of the U.S. National Oceanic and Atmospheric Administration and various Eoviet authors,atmospheric turbulence effects on MMW propagation will be discussed. These effes include fluctuations in intensity and phase, with phase scintillations causing variations in angle-of-arrival. The results of measurements of these phenomena will be presented.
出处
《电波科学学报》
EI
CSCD
1991年第1期10-17,共8页
Chinese Journal of Radio Science
