發(fā)布時間：2018-03-16 16:40

  本文選題：太赫茲　切入點(diǎn)：石墨烯　出處：《南京郵電大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：新型納米碳基材料石墨烯無限薄,表現(xiàn)出色散特性,在電磁、太赫茲通信系統(tǒng)等方面具有重要的應(yīng)用前景。本文針對石墨烯器件的應(yīng)用需求與數(shù)值分析的發(fā)展需要,提出一種分析石墨烯太赫茲頻段色散特性的數(shù)值方法,研究內(nèi)容涉及以下部分:對石墨烯的色散特性進(jìn)行準(zhǔn)確建模,使用Kubo公式計算其由帶內(nèi)和帶間表面電導(dǎo)率構(gòu)成的頻域表面電導(dǎo)率。使用矢量匹配法,以實(shí)極點(diǎn)-留數(shù)和/或復(fù)極點(diǎn)-留數(shù)共軛對的形式展開石墨烯頻域表面電導(dǎo)率和阻抗,通過改變矢量匹配法的擬合項(xiàng)數(shù)來研究項(xiàng)數(shù)對擬合精度的影響,同時對不同溫度和化學(xué)勢下的石墨烯頻域表面阻抗進(jìn)行有理近似,以此探討這些參數(shù)對頻域表面阻抗的影響。在此基礎(chǔ)上,使用矢量匹配法來擬合石墨烯在太赫茲頻段下的頻域表面阻抗,仿真結(jié)果表明通過較少的擬合項(xiàng)數(shù)即可達(dá)到比較精確的擬合結(jié)果。在上述研究基礎(chǔ)上,將石墨烯的頻域表面阻抗經(jīng)傅里葉逆變換獲得時域表面阻抗,根據(jù)表面阻抗邊界條件建立分析石墨烯的階數(shù)步進(jìn)時域積分方程,通過時域表面阻抗與時域電流作卷積體現(xiàn)石墨烯的色散特性。使用Laguerre多項(xiàng)式等性質(zhì)進(jìn)行推導(dǎo),獲得時域表面阻抗與時域電流卷積項(xiàng)的解析公式。使用加權(quán)Laguerre多項(xiàng)式作為時間基函數(shù),使用Galerkin法進(jìn)行空間和時間測試,推導(dǎo)出從積分方程建立到矩陣方程形成的主要公式。仿真結(jié)果表明時域電流是無條件穩(wěn)定的,此外,對比石墨烯與金屬平板的時域結(jié)果,表明石墨烯是色散的,對比由頻域矩量法所得到的仿真結(jié)果,進(jìn)一步驗(yàn)證本文所提出的分析石墨烯的階數(shù)步進(jìn)時域積分方程法的正確性。
[Abstract]:The novel nano-carbon based material graphene is infinitely thin and has excellent dispersion properties. It has an important application prospect in electromagnetic and terahertz communication systems. This paper aims at the development of graphene devices and numerical analysis. A numerical method for analyzing the dispersion characteristics of graphene terahertz band is presented. The research involves the following parts: the dispersion characteristics of graphene are modeled accurately. The frequency domain surface conductivity of graphene is calculated by using the Kubo formula, which consists of the in-band and inter-band surface conductivities. Using vector matching method, the surface conductivity and impedance of graphene in frequency domain are developed in the form of real pole-residue and / or complex pole-residue conjugate pairs. By changing the fitting term number of vector matching method, the influence of term number on fitting accuracy is studied. At the same time, the surface impedance of graphene in frequency domain under different temperature and chemical potential is obtained by rational approximation. The influence of these parameters on the surface impedance in frequency domain is discussed. On this basis, the frequency domain surface impedance of graphene in terahertz band is fitted by vector matching method. The simulation results show that more accurate fitting results can be obtained by using fewer fitting terms. On the basis of the above research, the surface impedance of graphene in frequency domain is obtained by Fourier inverse transform, and the surface impedance of graphene in time domain is obtained by inverse Fourier transform. According to the boundary condition of surface impedance, the order step time domain integral equation of graphene is established, and the dispersion characteristic of graphene is reflected by convolution of time domain surface impedance and time domain current. The properties of graphene are deduced by using Laguerre polynomials. The analytical formulas of the time domain surface impedance and the time domain current convolution term are obtained. The weighted Laguerre polynomial is used as the time basis function and the Galerkin method is used to carry out the space and time measurements. The main formulas from integral equation to matrix equation are derived. The simulation results show that the time domain current is unconditionally stable. In addition, compared with the time domain results of graphene and metal plate, it is shown that graphene is dispersive. By comparing the simulation results obtained from the method of moments in frequency domain, the correctness of the order step time domain integral equation method for graphene analysis proposed in this paper is further verified.
【學(xué)位授予單位】：南京郵電大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：O613.71;O241.8

【參考文獻(xiàn)】

相關(guān)期刊論文 前4條

1 潘登科;謝亞楠;劉志坤;耿莉;宋盼;;石墨烯在微波至可見光波段的電磁特性[J];中國科技論文;2015年18期

2 張健;鄧賢進(jìn);王成;林長星;陸彬;陳琦;;太赫茲高速無線通信:體制、技術(shù)與驗(yàn)證系統(tǒng)[J];太赫茲科學(xué)與電子信息學(xué)報;2014年01期

3 毛軍發(fā);黃一;吳林晟;唐e，

本文編號：1620760