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1.
X. Yang O. Drumm A. Arnold E. Borie G. Dammertz K. Koppenburg B. Piosczyk D. Wagner M. Thumm 《International Journal of Infrared and Millimeter Waves》2003,24(10):1599-1608
The quasi-optical mode converter for a frequency step-tunable gyrotron which consists of a dimpled-wall antenna (Denisov-type launcher) and a beam-forming mirror system has been optimized for 9 modes from TE17,6 at 105 GHz to TE23,8 at 143 GHz. The first mirror is a large quasi-elliptical focusing one; the second and third are phase-correcting mirrors with a non-quadratic shape of the surface. The results of calculations show that for these modes the Denisov-type launcher has a well-focused beam with low diffraction losses, and the radiation pattern presents an almost identical field shape for all modes considered. A multi-mode optimization of the phase-correcting mirrors with two different methods has been tested. The simulations show that the phase-correcting mirrors can be used for broadband operation in the frequency range from 105 GHz up to 143 GHz in the various design modes. This quasi-optical mode converter can achieve efficiencies of 94%-98% for converting the rotating high-order cylindrical cavity modes into the usable fundamental Gaussian mode. 相似文献
2.
X. Yang A. Arnold E. Borie G. Dammertz O. Drumm K. Koppenburg B. Piosczyk D. Wagner M. Thumm 《International Journal of Infrared and Millimeter Waves》2004,25(11):1557-1566
A broadband quasi-optical (QO) mode converter for a multi-frequency gyrotron has been designed and tested at Forschungszentrum Karlsruhe (FZK). The launcher is optimized for the TE22,8 mode at 140 GHz, but the radiated beams present an almost identically focused pattern for all 9 considered modes between 105 GHz (TE17,6) and 143 GHz (TE23,8). Combining with a beam-forming mirror system, which consists of a quasi-elliptical mirror and two phase-correcting mirrors with non-quadratic surface contour, further calculations show that efficiencies of more than 94% have been achieved for converting the rotating high-order cylindrical cavity modes into the usable fundamental Gaussian mode. Low power (cold) measurements show a good agreement with theoretical predictions. This QO mode converter can be used for the broadband operation of a multi-frequency 1 MW gyrotron. 相似文献
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I. Ogawa K. Yamada T. Idehara R. Pavlichenko 《International Journal of Infrared and Millimeter Waves》2002,23(2):189-203
In this paper we present a novel design of a quasi-optical system for conversion of gyrotron outputs into Gaussian-like beams. It consists of a quasi-optical antenna, two focusing mirrors and a filter which removes the side lobes of the beam. The system is appropriate as a transmission line for frequency tunable gyrotrons operating at TE0n mode. As an illustration of our approach, we present results which demonstrate the applicability of the developed system for conversion of the radiation generated by the Gyrotron FU IVA. The examples include conversion of three TE0n modes (TE02, 223 GHz; TE03, 323 GHz; TE04, 423 GHz) into Gaussian- like beams. 相似文献
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Design of a Quasi-Optical System to Convert TE0n Mode Outputs of a Gyrotron into Gaussian Beams 总被引:1,自引:0,他引:1
I. Ogawa K. Y. Yamada T. Idehara S. Sabchevski W. Kasparek 《International Journal of Infrared and Millimeter Waves》2000,21(4):577-592
In this paper we present a novel design of a quasi-optical system for conversion of gyrotron outputs into gaussian beams. It consists of a quasi-optical antenna, four focusing mirrors (parabolic cylinders) and a filter which removes the side lobes of the beam. The system is capable to convert three TE0n mode outputs into gaussian beams with waist size of 16.7 mm as well as four TE1n mode outputs into bi-gaussian beams with waist size of 10.9 mm in width and 16.5 mm in length. 相似文献
6.
V波段圆波导TE01模式激励器由矩形TE10模式到矩形TE20模式变换器和矩形TE20模式到圆波导TE01模式变换器组成。采用H面(磁面)转弯激励的方式实现矩形TE10模式到矩形TE20模式的变换;根据圆波导TE01模式的场分布特性,引入过模波导实现了矩形TE20到圆波导TE01的变换。计算结果表明设计的激励器转换效率在95%以上;模式纯度在98%以上的相对带宽可达4.2 GHz;其中在43.4 GHz处的最大转换效率为99.08%,纯度为99.20%。 相似文献
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利用模式展开和场匹配理论,建立了具有突变结构谐振腔的散射矩阵。在此基础上编制了FORTRAN计算程序,并对Ka波段TE01模回旋速调管的具有突变结构的开放式输出腔进行了数值计算。分析了回旋速调管输出腔的腔体长度和半径变化,以及输出耦合孔的半径和厚度变化对输出腔的品质因数和频率的影响。结果表明:由程序模拟输出腔所得到的计算结果与HFSS软件的结果一致;与冷测实验结果相比,品质因数的相对偏差为1.65%,谐振频率的偏差为10 MHz。 相似文献
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设计并分析了TE01斜接弯头结构,该结构由两段相同且垂直的模式变换段及与模式变换段呈45°斜接的金属镜面组成。整个结构等效于两个模式变换段对接,但中间存在间距为波导直径的缝隙。模式变换段将纯TE01模式转换为TE01和TE02的混合模式,该混合模式在缝隙中传播时电场呈现对称分布,从而降低了模式转换损耗,提高了传输效率。对设计的Ka波段TE01斜接弯头结构的理论仿真和加工实测结果表明:中心频点转换效率在98%以上,在2 GHz带宽内传输效率95%以上,插损小于0.2 dB,驻波小于1.2。 相似文献
9.
设计了一种高功率圆波导TM01-矩形波导TE10模式转换器,可以实现圆波导TM01模式与矩形波导TE10模式之间的相互转换。仿真结果表明:中心频率为9.7GHz时该模式转换器转换效率大于99.99%,回波损耗小于-40dB,转换效率大于90%时的带宽大于0.4GHz。调节底面短路圆波导长度可以实现模式转换器在9.2~10.1GHz范围内调谐(模式转换效率大于99%)。在圆波导和耦合段连接处引入倒角可有效降低场强,提高功率容量,注入功率0.7GW,其表面场强小于1 MV/cm。 相似文献
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Gregory G. Denisov Maxim L. Kulygin 《International Journal of Infrared and Millimeter Waves》2005,26(3):341-361
We study a transmission problem of an electromagnetic pulse with given transversal structure passing through a waveguide converter from TM01 to TE11 mode of circular waveguide. Using FDTD numerical simulation method we have investigated mode structure of the pulse at the output of the converter and its dependence on pulse length at the input. Also we have obtained frequency characteristic by calculating Fourier response for a pulse with wide spectrum. 相似文献
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G. Singh M. V. Kartikeyan A. K. Sinha B. N. Basu 《International Journal of Infrared and Millimeter Waves》2002,23(4):517-533
In this paper, the dispersion relation for a vane-loaded cylindrical waveguide, considering the azimuthal harmonic effects arising from the azimuthal periodicity of the vanes, excited in transverse electric (TE) modes and the gain for a gyro-TWT have been presented. The effects of beam and magnetic field parameters on two highly competing modes have been studied. 相似文献
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P. L. Francois M. J. Adams R. J. Mansfield R. D. Birch E. J. Tarbox 《Optical and Quantum Electronics》1982,14(6):483-499
Snyder's equivalent step-index method is extended to the case of graded profiles with a depressed cladding. This method is then used to determine the limit of monomode operation. Comparison with the results obtained by an exact numerical technique is made for a large variety of simulated profiles, including those with ripples in the cladding. Conclusions are drawn concerning the sensitivity of various profile-shapes to such ripple structure. The method is applied also to measured profiles, reconstructed by a well-known tomographic procedure. In this latter case a comparison is made with experimentally determined values.On leave from CNET, Lannion, France. 相似文献
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Alekseev R.A. Lapkin I. V. Lapinov A. V. Khabarova T.A. Golubyatnikov G.Yu. Andriyanov A. F. Schkaev A.P. Zemlyanukha P.M. 《Radiophysics and Quantum Electronics》2022,64(12):873-883
Radiophysics and Quantum Electronics - We describe a new sub-Doppler spectrometer with an enlarged gas cell, which was created at the IAP RAS for high-precision laboratory measurements of molecular... 相似文献
16.
Hui-zhen Li Xiang-wen Chen Si-we Lyu 《International Journal of Infrared and Millimeter Waves》2001,22(6):905-915
This paper presents quasi-optics techniques, millimeter techniques and a global optimization method etc techniques. It is a structure of quasi-optics power combiner, that includes a spherical reflection, that the radius of the curvature is R and another one is a hybrid reflector that is called input reflector. The space of the both reflectors is LL. The monolithic source-array is made up of 25 Gunn diodes that are mounted of parallel brass bars that have low thermal resistance. And the bars are fixed on the inner plane surface of the hybrid reflector. The hybrid reflector made up of a plane and a spherical, that the radius of the curvature are R. It is designed that higher fundamental mode power, larger fractional power of fundamental mode power and more combining efficiency of the quasi-optics power combiner.This paper describes an algorithm, which can determine the global optima of the power combiner of solid-state millimeter wave resonator. The global optimization method can determine a neighborhood of the global optima of an objective function and an estimation of the global optima. In the quasi-optical resonator, the objective functions are the fundamental mode power, the fractional power of fundamental mode and the combining efficiency respectively. 相似文献
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Yin Li Chongqing Jiao Jirun Luo 《International Journal of Infrared and Millimeter Waves》2007,28(12):1155-1160
A mode converter with multi-waveguide output for millimeter wave gyro-device applications is proposed in this article, which
is used to convert the TE01 circular waveguide mode into the TE10 rectangular waveguide mode. Computer simulations with Ansoft HFSS code show that the energy transmission coefficient of larger
than 95.96% may be reached in the frequency range from 34.094 GHz to 35.8 GHz (a bandwidth of 1.706 GHz) at a VSWR of lower
than 1.5 for the input operating mode. 相似文献
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A. A. Bogdashov A. V. Chirkov G. G. Denisov A. N. Kuftin Yu. V. Rodin E. A. Soluyanova V. E. Zapevalov 《International Journal of Infrared and Millimeter Waves》2005,26(6):771-785
A high-efficiency mode converter of the ITER gyrotron operating mode into the Gaussian wave beam has been developed. It includes an irradiating waveguide with shallow deformation and profiled quasi-optical mirrors to increase the Gaussian content. Low-power tests were carried out with a TE25.10 mode exciter and a mode converter. A prototype of the short-pulsed 170 GHz gymtmn with the new converter was manufactured and tested. Diffraction losses measured inside the tube were less then 2% at the 1 MW power level. A high Gaussian mode content in the output beam has been also demonstrated. 相似文献
19.
We design a single-ridged coaxial hybrid coupler which excites a TE011 mode of high mode content in a cylindrical cavity, resonating at 28.2GHz. The coupler consists of a WR-28 rectangular waveguide, a coaxial TEn11 cavity, and a cylindrical TE011 cavity. Both TE311 coaxial cavity and TE411 single-ridged coaxial cavity are analyzed to examine the TE011 mode purity in the central cavity. Mode purity analysis is performed by a field expansion method using Fourier-Bessel orthonormal basis functions. Numerical calculations predict that the TE411 single-ridged coaxial cavity excites the TE011 mode with mode purity of 98.6%, which is improved by 3% higher compared with the TE311 coaxial cavity. Measurements on the single-ridged coaxial coupler show a resonant frequency at 28.078GHz and ohmic and external Qs of 1560, 473 respectively, which are in good agreement with the simulated results of a 3-D finite element electromagnetic code. 相似文献
20.
Shinzo Muto Tomoyasu Sakagami Yoshihiko Sakane Akira Namazue Eisuke Nihei Yasuhiro Koike 《Optical Review》1996,3(2):120-123
A novel TE-TM mode converter using optically active polymer: poly-1-menthylmethacrylate (PMtMA) was studied theoretically and experimentally. In a three-layered slab waveguide consisting of the PMtMA core layer on a fused quartz substrate, a low-loss TE0-TM0 mode conversion with an efficiency of 60 to 70% was easily obtained for the first time at a wavelength of 441.6 nm. The method to achieve a phase-matched operation of this polymer TE-TM mode converter was also discussed. 相似文献