太赫茲回旋管準光模式變換器的研究
發(fā)布時間：2018-07-25 12:54
【摘要】：太赫茲波介于毫米波和紅外之間,它的產(chǎn)生和應用是目前國際上的一個研究熱點。回旋管已經(jīng)被證明是最有可能產(chǎn)生大功率太赫茲信號的器件。太赫茲波為亞毫米波,其波長很短,在波導中傳輸損耗大。為增大注-波互作用腔體的尺寸,太赫茲回旋管通常工作于高階模式。然而高階模式電磁波不利于在自由空間中傳輸和應用,因此為了增大回旋管的收集極半徑,提高輸出功率,需要采用準光模式變換器橫向輸出太赫茲波。采用準光模式變換器可以減少輸出窗的反射,防止反射波加熱電子注從而影響注-波互作用的穩(wěn)定性。因此,研究太赫茲回旋管準光模式變換器具有非常重要的意義。本文首先對W波段回旋管的準光模式變換器進行理論研究和實驗,然后對工作于高階旋轉(zhuǎn)模式TE17,4,輸出頻率為0.42THz的回旋管準光模式變換器進行研究分析。本文的主要內(nèi)容和創(chuàng)新之處可概述如下:1、采用正弦幅度曲線代替了傳統(tǒng)的梯形折線幅度曲線設計了太赫茲波的Denisov輻射器。Denisov輻射器是Vlasov輻射器改進型結(jié)構(gòu),它采用了一段壁擾動波導結(jié)構(gòu)對輸入的電磁波進行預聚束成類高斯束分布。擾動結(jié)構(gòu)通常采用螺旋波紋形式,擾動深度沿傳播方向成梯形折線分布,這種分布結(jié)構(gòu)在折線的拐點處存在奇點。奇點的存在使波導內(nèi)耦合系數(shù)的推導與數(shù)值計算帶來了困難。本文采用的正弦幅度曲線存在連續(xù)偏導數(shù),避免了奇點的存在,減少了計算難度,同時也減小了寄生模式。2、采用矢量繞射積分法計算了輻射口輸出的輻射場,輻射場分布與給出的實驗結(jié)果基本一致。高階模式輸入的輻射器采用螺旋切口結(jié)構(gòu),電磁波從螺旋切口向外輻射,輻射場的功率和效率是影響整個準光模式變換器的性能的主要因素。因此需要精確計算輻射口的場分布。目前國際上主要采用三維仿真軟件進行仿真分析,但隨著工作模式和頻率的提高,三維仿真軟件需要大量的計算機資源和時間。矢量繞射積分法既可以滿足計算精度的要求也可以大大減小計算機資源和縮短計算時間。3、矢量繞射積分法與標量繞射積分法相結(jié)合計算各個反射鏡面上的場分布。標量繞射積分法具有計算量小,計算速度快等優(yōu)點,但由于忽略了鏡面邊沿上的場分布,計算精度被降低了。矢量繞射積分法計算量大,精度高。本文結(jié)合兩者的優(yōu)點,先采用標量繞射積分法計算出各個鏡面的位置和尺寸,再采用矢量繞射法精確計算鏡面上的場分布和精確調(diào)整反射面的各個幾何參數(shù)。4、設計了工作于0.1THz TE6,2的太赫茲準光模式變換器。在傳統(tǒng)的擾動方程的基礎上增加了多項擾動因子,增強了擾動結(jié)構(gòu)的靈活性。采用耦合波理論計算了擾動段內(nèi)各個模式沿縱向的功率分布,分析了輻射口的高斯束參數(shù),分析了輸出電磁波的旋轉(zhuǎn)方向?qū)δＪ阶儞Q器的轉(zhuǎn)換效率和功率的影響。結(jié)合本文所依賴的課題,采用四個反射鏡對輸出的輻射場進行相位修正。5、設計了工作于0.42THz TE17,4高階模式高過模的太赫茲回旋管準光模式變換器。由于工作模式很高,可能存在很多的寄生模式,需要分析波導內(nèi)可能耦合出的各個寄生模式,從而采用相應的措施抑制寄生模式。太赫茲波長很短,波導截止半徑很小,因此回旋管收集極工作于高過模狀態(tài),不適合采用Denisov輻射器直接轉(zhuǎn)換,需要一節(jié)過渡波導把收集極半徑進行適當?shù)氖湛s,然后再輸入到準光模式變換器內(nèi)進行模式轉(zhuǎn)換。6、對所設計的準光模式變換器進熱測實驗。準光模式變換器是準光輸出回旋管的重要組成部分,是為便于后級應用和增加降壓收集極作為充分的準備。本文設計的準光模式變換順增補了國內(nèi)的空白,研制出了國內(nèi)第一支準光輸出高功率回旋管。
[Abstract]:Terahertz wave is between the millimeter wave and the infrared, and its production and application are a hot spot of research in the world. The gyrotron has been proved to be the most likely device to produce high power terahertz signals. The terahertz wave is submillimeter wave, its wavelength is very short, and the transmission loss is large in the waveguide. It is too large to increase the size of the cavity of the injection wave interaction. The Hertzian gyrotron usually works in the high order mode. However, the high order mode electromagnetic wave is not conducive to the transmission and application in the free space. Therefore, in order to increase the collector radius and increase the output power of the gyrotron, the quasi optical mode converter is needed to output the terahertz wave laterally. It is very important to study the quasi optical mode converter of the terahertz gyrotron. This paper first studies and experiments on the quasi optical mode converter of the W band gyrotron, and then works on the high order rotation mode TE17,4, and the output frequency is 0.42THz. The main contents and innovations of this paper can be summarized as follows: 1, using the sinusoidal amplitude curve instead of the traditional trapezoid fold line amplitude curve, the Denisov radiator.Denisov radiator of the terahertz wave is an improved structure of the Vlasov radiator, and it adopts a wall disturbance waveguide structure. The input electromagnetic wave is preclustered into Gauss beam distribution. The disturbance structure usually uses the form of spiral ripple. The disturbance depth is trapezoid fold along the direction of propagation. This distribution structure has odd points at the turning point of the folded line. The existence of singularity brings difficulties to the deduction of the coupling coefficient in the waveguide and the numerical calculation. There is a continuous partial derivative of the string amplitude curve, which avoids the existence of the singularities, reduces the difficulty of calculation, and reduces the parasitic mode.2. The radiation field is calculated by the vector diffraction integral method. The distribution of the radiation field is basically the same as the experimental results. The high order model input radiator uses a spiral incision structure and electromagnetic wave. The power and efficiency of the radiation field are the main factors affecting the performance of the whole quasi optical mode converter. Therefore, it is necessary to accurately calculate the field distribution of the radiant port. At present, the three dimensional simulation software is mainly used in the simulation and analysis in the world. But with the improvement of the working mode and frequency, the three-dimensional simulation software needs a large amount. The vector diffraction integral method can not only satisfy the requirement of calculation precision, but also greatly reduce the computer resources and shorten the calculation time.3. The vector diffraction integral method and the scalar diffraction integral method are combined to calculate the field distribution on the mirror surface. The scalar diffraction product method has the advantages of small calculation, fast calculation and so on. But because of neglecting the field distribution on the edge of the mirror, the calculation precision is reduced. The vector diffraction integral method has a large calculation and high precision. In this paper, the position and size of the mirror surface are calculated by the scalar diffraction integral method, and the vector diffraction method is used to accurately calculate the field distribution on the mirror surface and the precise adjustment of the reflector. Each geometric parameter.4 is designed for the terahertz quasi optical mode converter working in 0.1THz TE6,2. On the basis of the traditional perturbation equation, a number of disturbance factors are added to enhance the flexibility of the disturbance structure. The coupling wave theory is used to calculate the longitudinal power distribution of each mode in the disturbance section, and the Gauss beam parameter of the radiant port is analyzed. The influence of the rotation direction of the output electromagnetic wave on the conversion efficiency and power of the mode converter is analyzed. Combined with the subject of this paper, four mirrors are used to correct the output of the radiation field by phase correction.5. A quasi optical mode converter working in the high mode high mode 0.42THz TE17,4 mode high mode overmodel is designed. The mode is very high, and there may be many parasitic modes. It is necessary to analyze the parasitic modes that may be coupled in the waveguide, so that the corresponding measures can be used to suppress the parasitic mode. The terahertz wavelength is very short and the cut-off radius of the waveguide is very small. Therefore, the collector of the gyrotron works on the high overmode state, and is not suitable for direct conversion of the Denisov radiator. In a transition waveguide, the collector radius is properly contracted and then entered into the quasi optical mode converter to carry out the mode conversion.6, and the design of the quasi optical mode converter is put into heat test. The quasi optical mode converter is an important part of the quasi optical output gyrotron, which is used for the post stage application and the increase of the depressurization collector. The quasi optical mode transformation designed in this paper has supplemented the domestic blank and developed the first quasi optical output high power gyrotron in China.
【學位授予單位】：電子科技大學
【學位級別】：博士
【學位授予年份】：2016
【分類號】：TN12
[Abstract]:Terahertz wave is between the millimeter wave and the infrared, and its production and application are a hot spot of research in the world. The gyrotron has been proved to be the most likely device to produce high power terahertz signals. The terahertz wave is submillimeter wave, its wavelength is very short, and the transmission loss is large in the waveguide. It is too large to increase the size of the cavity of the injection wave interaction. The Hertzian gyrotron usually works in the high order mode. However, the high order mode electromagnetic wave is not conducive to the transmission and application in the free space. Therefore, in order to increase the collector radius and increase the output power of the gyrotron, the quasi optical mode converter is needed to output the terahertz wave laterally. It is very important to study the quasi optical mode converter of the terahertz gyrotron. This paper first studies and experiments on the quasi optical mode converter of the W band gyrotron, and then works on the high order rotation mode TE17,4, and the output frequency is 0.42THz. The main contents and innovations of this paper can be summarized as follows: 1, using the sinusoidal amplitude curve instead of the traditional trapezoid fold line amplitude curve, the Denisov radiator.Denisov radiator of the terahertz wave is an improved structure of the Vlasov radiator, and it adopts a wall disturbance waveguide structure. The input electromagnetic wave is preclustered into Gauss beam distribution. The disturbance structure usually uses the form of spiral ripple. The disturbance depth is trapezoid fold along the direction of propagation. This distribution structure has odd points at the turning point of the folded line. The existence of singularity brings difficulties to the deduction of the coupling coefficient in the waveguide and the numerical calculation. There is a continuous partial derivative of the string amplitude curve, which avoids the existence of the singularities, reduces the difficulty of calculation, and reduces the parasitic mode.2. The radiation field is calculated by the vector diffraction integral method. The distribution of the radiation field is basically the same as the experimental results. The high order model input radiator uses a spiral incision structure and electromagnetic wave. The power and efficiency of the radiation field are the main factors affecting the performance of the whole quasi optical mode converter. Therefore, it is necessary to accurately calculate the field distribution of the radiant port. At present, the three dimensional simulation software is mainly used in the simulation and analysis in the world. But with the improvement of the working mode and frequency, the three-dimensional simulation software needs a large amount. The vector diffraction integral method can not only satisfy the requirement of calculation precision, but also greatly reduce the computer resources and shorten the calculation time.3. The vector diffraction integral method and the scalar diffraction integral method are combined to calculate the field distribution on the mirror surface. The scalar diffraction product method has the advantages of small calculation, fast calculation and so on. But because of neglecting the field distribution on the edge of the mirror, the calculation precision is reduced. The vector diffraction integral method has a large calculation and high precision. In this paper, the position and size of the mirror surface are calculated by the scalar diffraction integral method, and the vector diffraction method is used to accurately calculate the field distribution on the mirror surface and the precise adjustment of the reflector. Each geometric parameter.4 is designed for the terahertz quasi optical mode converter working in 0.1THz TE6,2. On the basis of the traditional perturbation equation, a number of disturbance factors are added to enhance the flexibility of the disturbance structure. The coupling wave theory is used to calculate the longitudinal power distribution of each mode in the disturbance section, and the Gauss beam parameter of the radiant port is analyzed. The influence of the rotation direction of the output electromagnetic wave on the conversion efficiency and power of the mode converter is analyzed. Combined with the subject of this paper, four mirrors are used to correct the output of the radiation field by phase correction.5. A quasi optical mode converter working in the high mode high mode 0.42THz TE17,4 mode high mode overmodel is designed. The mode is very high, and there may be many parasitic modes. It is necessary to analyze the parasitic modes that may be coupled in the waveguide, so that the corresponding measures can be used to suppress the parasitic mode. The terahertz wavelength is very short and the cut-off radius of the waveguide is very small. Therefore, the collector of the gyrotron works on the high overmode state, and is not suitable for direct conversion of the Denisov radiator. In a transition waveguide, the collector radius is properly contracted and then entered into the quasi optical mode converter to carry out the mode conversion.6, and the design of the quasi optical mode converter is put into heat test. The quasi optical mode converter is an important part of the quasi optical output gyrotron, which is used for the post stage application and the increase of the depressurization collector. The quasi optical mode transformation designed in this paper has supplemented the domestic blank and developed the first quasi optical output high power gyrotron in China.
【學位授予單位】：電子科技大學
【學位級別】：博士
【學位授予年份】：2016
【分類號】：TN12
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1 宋剛永;聶開俊;;W波段準光模式變換器的優(yōu)化仿真設計[J];信息技術(shù);2010年11期
2 王鴻昶,錢書珍;螺旋耦合H°_(01)—H°_(02)模式變換器的若干問題[J];電子科學學刊;1983年02期
3 張靖華;大功率同軸扇形模式變換器[J];中國科學技術(shù)大學學報;1988年01期
4 錢書珍,劉剛;開槽耦合型H_(01)~ο，
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