本文關(guān)鍵詞：220GHz折疊波導(dǎo)慢波結(jié)構(gòu)設(shè)計　出處：《北京信息科技大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 太赫茲 折疊波導(dǎo) 行波管 冷測特性 注—波互作用 真空微電子

【摘要】：太赫茲,指頻率介于0.1THz~10THz之間的電磁波,位于毫米波和紅外之間。它具備諸多優(yōu)點,科學(xué)價值重大,應(yīng)用前景廣闊,可用于物體成像、環(huán)境監(jiān)測、醫(yī)療診斷,亦可用于衛(wèi)星通信和軍用雷達系統(tǒng)等方面。在太赫茲源研制方面,輻射功率低是限制太赫茲技術(shù)發(fā)展的主要瓶頸之一,因此需要一種理想的太赫茲輻射源放大器。而行波管是一類應(yīng)用最廣泛的電真空放大器,應(yīng)用在太赫茲頻段,可以實現(xiàn)對太赫茲波的功率放大,用于構(gòu)建高效率的太赫茲源,對太赫茲技術(shù)的發(fā)展具有十分重要的意義。慢波結(jié)構(gòu)是行波管的核心部件,折疊波導(dǎo)慢波結(jié)構(gòu)作為一種全金屬的結(jié)構(gòu),散熱能力強,帶寬大,輸入輸出耦合結(jié)構(gòu)簡單且易于加工,高頻損耗小。因此,太赫茲折疊波導(dǎo)行波管吸引了國內(nèi)外眾多研究機構(gòu)的廣泛關(guān)注,極具發(fā)展?jié)摿Α?20GHz是太赫茲頻段低端的一個大氣窗口,有極高應(yīng)用價值,是各國競相研究的頻段。針對當(dāng)前小型化、寬頻帶太赫茲輻射源需求,本文設(shè)計了以折疊波導(dǎo)為慢波電路的220GHz行波管,并進行了慢波電路樣品加工工藝的初步探索。論文內(nèi)容如下:(1)對慢波結(jié)構(gòu)的色散特性、耦合阻抗以及損耗特性進行了理論分析,開發(fā)了參數(shù)獲取工具,設(shè)計了220GHz折疊波導(dǎo)慢波結(jié)構(gòu),并在CST微波工作室TM中進行了仿真。冷測特性計算結(jié)果表明,該慢波結(jié)構(gòu)在220GHz附近,色散曲線較平緩,耦合阻抗約2?。(2)結(jié)合注—波互作用理論,優(yōu)化設(shè)計了互作用電路,在CST粒子工作室TM仿真工具軟件中對220GHz折疊波導(dǎo)行波管進行了全管特性仿真,分析了注—波互作用的物理過程,探究了增益與同步電壓、互作用電路長度、聚焦磁場、電子發(fā)射角度、電子能散度等參數(shù)的關(guān)系,給出了60周期互作用長度的折疊波導(dǎo)行波管輸出信號時域及頻域特性,提取了功率水平、增益、帶寬等指標。(3)針對220GHz折疊波導(dǎo)慢波結(jié)構(gòu)截面尺寸與標準波導(dǎo)不一致的問題,結(jié)合微加工工藝難度和可行性,設(shè)計了采用直漸變方式的慢波電路到標準波導(dǎo)過渡段,并在CST微波工作室TM中進行了仿真,駐波比滿足整管設(shè)計的要求。(4)結(jié)合微細加工工藝,對太赫茲折疊波導(dǎo)慢波電路的工藝進行了初步探討,采用微細電火花技術(shù)(WEDM),加工了220GHz折疊波導(dǎo)慢波結(jié)構(gòu)的初步樣品,分析了其中存在的問題并提出相應(yīng)的解決辦法,對進一步的工藝優(yōu)化提出了建議。上述關(guān)于220GHz折疊波導(dǎo)慢波結(jié)構(gòu)的理論分析、綜合設(shè)計、三維注—波互作用模擬仿真、加工工藝的探索等工作,為后續(xù)研制220GHz折疊波導(dǎo)行波管打下了基礎(chǔ)。
[Abstract]:Terahertz, a electromagnetic wave with a frequency of 0.1 THz-10 THz, is located between millimeter wave and infrared. It has many advantages, great scientific value, wide application prospect and can be used for object imaging. Environmental monitoring, medical diagnosis, satellite communications and military radar systems can also be used. In the development of terahertz sources, low radiation power is one of the main bottlenecks limiting the development of terahertz technology. Therefore, an ideal THz emitter amplifier is needed, and TWT is the most widely used electric vacuum amplifier, which can amplify the THz power. It is very important for the development of terahertz technology to construct high efficiency terahertz source. Slow wave structure is the core component of TWT, and folded waveguide slow wave structure is a kind of all metal structure. Because of its strong heat dissipation, large bandwidth, simple input and output coupling structure, easy processing and low loss at high frequency, THz folded waveguide TWT has attracted wide attention from many research institutions at home and abroad. The high potential .220 GHz is an atmospheric window at the low end of the terahertz band, which has very high application value and is the frequency band studied by many countries. According to the demand of the current miniaturization, broadband terahertz radiation source. In this paper, a 220 GHz TWT with folded waveguide as slow wave circuit is designed, and the processing technology of slow wave circuit sample is studied. The main contents of this paper are as follows: 1) Dispersive characteristics of slow wave structure. The coupling impedance and loss characteristics are analyzed theoretically. A parameter acquisition tool is developed and a 220 GHz folded waveguide slow-wave structure is designed. The simulation results in TM of CST microwave studio show that the slow-wave structure is in the range of 220 GHz, the dispersion curve is smooth and the coupling impedance is about 2? Based on the theory of beam-wave interaction, the interaction circuit is optimized, and the full-tube characteristics of 220GHz folded waveguide TWT are simulated in the TM simulation software of CST particle studio. The physical process of beam-wave interaction is analyzed, and the relationship between gain and synchronous voltage, interaction circuit length, focusing magnetic field, electron emission angle and electron energy divergence is explored. The time-domain and frequency-domain characteristics of the output signal of the folded waveguide TWT with the interaction length of 60 cycles are given. The power level and gain are extracted. Aiming at the problem that the cross section size of slow wave structure of 220 GHz folded waveguide is not consistent with the standard waveguide, it is difficult and feasible to combine the micro-fabrication technology. The transition section from slow wave circuit to standard waveguide is designed and simulated in CST microwave studio TM. The VSWR meets the requirements of the whole tube design. The technology of THz folded waveguide slow-wave circuit is discussed. A preliminary sample of 220GHz folded waveguide slow-wave structure is fabricated by using micro-EDM technique. The existing problems are analyzed and the corresponding solutions are put forward, and suggestions for further technological optimization are put forward. The theoretical analysis and comprehensive design of the 220GHz folded waveguide slow-wave structure are described above. The simulation of 3D beam-wave interaction and the exploration of machining technology have laid the foundation for the further development of 220GHz folded waveguide TWT.
【學(xué)位授予單位】：北京信息科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TN124

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本文編號：1434254