【摘要】：太赫茲波是指頻率范圍為0.1-10THz的電磁波。太赫茲的特殊性質使其在生物醫學、無損探傷、安全檢測和移動通信等領域都有著廣闊的應用前景。尤其在移動通信領域越來越受到世界各國的重視和青睞。隨著人們對數據傳輸速率的要求越來越高,發展更高頻率的載波是滿足大數據傳輸的必然趨勢。然而太赫茲輻射在通信、雷達這些數據傳輸方面的應用與THz的大氣傳輸特性緊密相關。大氣對THz的吸收衰減效應以水分子的吸收作用最強。所以研究THz在水蒸汽中的傳輸效應是確定THz的大氣窗口位置和寬度的重要依據。本實驗搭建基于太赫茲時域光譜技術的透射式THz-TDS系統為實驗平臺,調整THz傳輸行程為0.5m,1m,2m,3m和密閉環境濕度范圍在0到80%。采用等效時間取樣原理重構太赫茲時域波形,以Lab View開發的軟件采集和存儲實驗數據。數據處理過程首先需要對時域信號經過傅里葉變換,在頻域上提取振幅和相位信息。最后采用L.Duvillaret和T.D.Dorney等人提出的提取材料光學參數的經典理論計算THz在不同濕度和不同傳輸行程下的吸收系數和透射率等參數。通過本實驗大量數據分析得到如下結論,隨著空氣濕度的升高,太赫茲時域光譜峰值逐漸降低,各窗口的傳輸率降低,傳輸窗口被壓縮。隨著水蒸汽太赫茲傳輸行程的增加,各窗口的傳輸率逐漸降低,傳輸窗口被壓縮。
[Abstract]:Terahertz wave refers to electromagnetic wave with frequency range of 0.1-10THz. The special properties of terahertz make it have broad application prospects in biomedicine, nondestructive testing, security testing and mobile communication. Especially in the field of mobile communication, it has been paid more and more attention and favored by all countries in the world. With the higher and higher requirements of data transmission rate, the development of higher frequency carrier is to meet the inevitable trend of big data transmission. However, the application of terahertz radiation in communication and radar data transmission is closely related to the atmospheric transmission characteristics of THz. The absorption and attenuation effect of THz by atmosphere is the strongest among water molecules. Therefore, the study of the transport effect of THz in steam is an important basis for determining the position and width of the atmospheric window of THz. In this experiment, a transmission THz-TDS system based on terahertz time domain spectroscopy is built as the experimental platform. The transmission stroke of THz is adjusted to 0.5m, 1m, 2m, 3m and the humidity range of closed environment is 0 to 80%. The terahertz time domain waveform is reconstructed by equivalent time sampling principle, and the experimental data are collected and stored with the software developed by Lab View. In the process of data processing, it is necessary to extract amplitude and phase information in frequency domain by Fourier transform of time domain signal. Finally, the classical theory of extracting optical parameters of materials proposed by L.Duvillaret and T.D.Dorney et al is used to calculate the absorption coefficient and transmittance of THz under different humidity and different transmission paths. Through the analysis of a large number of data in this experiment, it is concluded that with the increase of air humidity, the peak value of terahertz time domain spectrum decreases gradually, the transmission rate of each window decreases, and the transmission window is compressed. With the increase of steam terahertz transmission stroke, the transmission rate of each window decreases gradually, and the transmission window is compressed.
【學位授予單位】：西南科技大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN011

【參考文獻】

相關碩士學位論文 前1條

1 許祖兵;激光大氣傳輸特性分析研究[D];南京理工大學;2006年

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本文編號：2481220