准光模式变换器研究与设计

研究了将回旋管及其他高功率微波器件的振荡输出模式转换成准高斯波束的准光模式变换器,实现了准高斯模TEM00的横向输出。利用几何光学分析了模式在波导中的传播,进一步分析了伏拉索夫（Vlasov）辐射器的工作机理,运用矢量绕射理论计算出辐射场; 通过编程设计了将94 GHz、模式为TE62的毫米波转化为准高斯波束的准光模式变换器。结果表明:通过设计Vlasov辐射器和两级反射镜,可以在窗口处得到准高斯波束, 整个系统的功率效率达到87.5%。     

W波段边廊模回旋管准光模式变换器的研究与设计

详细研究并设计了一个由Vlasov螺旋开口辐射器和两级曲面反射器组成的边廊模回旋管准光模式变换器.首先采用几何光学理论研究了设计的Vlasov型准光模式变换器的工作机理,在此基础上,再利用矢量绕射理论中的口径场积分法和表面电流积分法编写了模拟仿真程序,最后结合W波段边廊模回旋管的具体设计参数,应用所编写程序详细分析了工作模式在此变换器中的模式变换过程.模拟结果表明,W波段回旋管中的TE_12,2边廊模在输出窗处被转换为能量集中的准Gauss波束. 关键词： 回旋管 边廊模 准光模式变换器 W波段     

W波段边廊模回旋管准光模式变换器的研究与设计

详细研究并设计了一个由Vlasov螺旋开口辐射器和两级曲面反射器组成的边廊模回旋管准光模式变换器.首先采用几何光学理论研究了设计的Vlasov型准光模式变换器的工作机理,在此基础上,再利用矢量绕射理论中的口径场积分法和表面电流积分法编写了模拟仿真程序,最后结合W波段边廊模回旋管的具体设计参数,应用所编写程序详细分析了工作模式在此变换器中的模式变换过程.模拟结果表明,W波段回旋管中的TE_12,2边廊模在输出窗处被转换为能量集中的准Gauss波束.     

140 GHz回旋管准光模式变换器的设计（英）

针对一种由Denisov型辐射器和第一面镜为准抛物镜的四级反射镜面系统组成的准光模式变换器开展了详细的研究和设计。利用耦合模理论和矢量绕射理论设计了波纹波导准光模式变化器,通过编写仿真程序进行数值优化完成了140 GHz,TE28,8回旋管准光模式变换器的设计。仿真结果表明,抛物面反射镜的焦距对矢量高斯效率影响较大,输出窗口处得到了较好的高斯波束,标量高斯效率达到98%,矢量高斯效率达到90%。     

140GHz回旋管准光模式变换器的设计（英文）

针对一种由Denisov型辐射器和第一面镜为准抛物镜的四级反射镜面系统组成的准光模式变换器开展了详细的研究和设计。利用耦合模理论和矢量绕射理论设计了波纹波导准光模式变化器,通过编写仿真程序进行数值优化完成了140GHz,TE28,8回旋管准光模式变换器的设计。仿真结果表明,抛物面反射镜的焦距对矢量高斯效率影响较大,输出窗口处得到了较好的高斯波束,标量高斯效率达到98%,矢量高斯效率达到90%。     

94 GHz TE_(6,2)模式Denisov辐射器的研究

准光辐射器是回旋管内置准光模式变换器的重要组成部分.采用几何光学理论分析了圆波导中高阶旋转模式电磁波的准光传输特性,分析了螺旋非规则光滑圆波导中电磁波的传输和模式耦合机理,推导任意扰动的圆波导内模式间的耦合波方程及其相关系数.根据耦合波理论编制准光模式变换器的数值计算程序,分析了Denisov型辐射器内激励起的波导模式的功率分布规律和波导壁上的纵向磁场分布,以及辐射器螺旋切口的辐射场的分布和辐射波束的特征,并采用三维全波仿真软件进行对比模拟.优化了工作频率为94 GHz,TE6,2模式的Denisov型辐射器,其输出功率效率高达98%;加工成实物并内置于回旋振荡内进行热测实验,在回旋管的输出窗处获得了高斯分布的烧斑图.此结果表明测试结果与计算基本一致.     

110GHz回旋管Denisov型准光模式变换器的研究与设计

对一种由Densiov型辐射器和四面反射镜面系统组成的准光模式变换器开展了详细的研究和设计。采用几何光学理论,分析了Denisov型辐射器的工作原理,推导了模式叠加形成高斯分布的过程。基于耦合模理论,提出了辐射器波纹波导的设计方法。针对110GHz,TE22,6模回旋管的具体参数设计和优化了辐射器和镜面系统,编写仿真程序,对波导切口处辐射场和镜面散射场进行数值模拟。计算结果表明,输出窗口处得到较好的高斯波束,高斯效率达到95.8%,功率转换效率为94.7%。     

高阶不对称体模回旋管Denisov型准光模式变换器（英）

详细研究了Denisov型准光模式变换器的原理和设计方法。应用几何光学理论对Denisov型开口辐射器的工作过程进行了分析,并给出了基于耦合模理论的辐射器不规则扰动段的设计方法。开发了基于耦合模理论、矢量衍射积分和物理光学法的仿真程序GQOMC-D,并将该程序的计算结果与文献报道结果进行了对比验证。利用该程序设计了一种110 GHz TE22,6模回旋振荡管准光模式变换器,仿真结果显示在输出窗上得到了场型较好的高斯波束,其模式纯度为98.4%,模式变换器的能量转换效率为94.7%。     

高阶不对称体模回旋管Denisov型准光模式变换器（英文）

详细研究了Denisov型准光模式变换器的原理和设计方法。应用几何光学理论对Denisov型开口辐射器的工作过程进行了分析,并给出了基于耦合模理论的辐射器不规则扰动段的设计方法。开发了基于耦合模理论、矢量衍射积分和物理光学法的仿真程序GQOMC-D,并将该程序的计算结果与文献报道结果进行了对比验证。利用该程序设计了一种110GHz TE22,6模回旋振荡管准光模式变换器,仿真结果显示在输出窗上得到了场型较好的高斯波束,其模式纯度为98.4%,模式变换器的能量转换效率为94.7%。     

X波段过模弯曲圆波导TM01-HE11模式变换器研究

在波束波导和反射面天线的馈源应用中, 为了产生低副瓣且方向图等化的高斯波束, 需要将高功率微波转换为准高斯模HE₁₁模辐射. 本文利用弯曲圆波导可同时从TM₀₁模产生TE₁₁模和TM₁₁模的原理, 提出了采用双弯曲过模圆波导结构直接将TM₀₁转换为HE₁₁的模式变换器, 避免了常规微波领域中首先将TM₀₁转换为TE₁₁再用波纹式或半径渐变式TE₁₁-HE₁₁转换器转换为准高斯波束功率容量不足或尺寸过长的不足. 基于模式耦合理论和Taguchi优化算法对模式变换器的弯曲半径、相移直端长度及引入位置进行了优化, 使输出的TE₁₁和TM₁₁成一定比率, 以组成HE₁₁模式, 并对设计的模式变换器进行了全电磁波仿真分析, 结果表明输出波束的标量高斯含量在9.05–9.8 GHz范围内均高于99%, 理论功率容量可达4.5 GW. 关键词： 高功率微波 模式耦合理论 Taguchi优化算法 模式变换器     

An improved design for quasi-optical mode conversion of whispering gallery mode gyrotron radiation

Results are reported of a theoretical and experimental investigation of a quasi-optical mode converter for the transformation of whispering gallery mode gyrotron output into a linearly polarized Gaussian like beam. The mode converter consists of a helically cut waveguide launcher, similar to that originally proposed by Vlasovet al, followed by a focusing mirror. Theoretical results using aperture field methods indicate that the length of the waveguide launcher is of critical importance in providing a confined radiation pattern. Experimental results on the radiation pattern were obtained for several launcher lengths using a 0.6 MW, 149 GHz pulsed gyrotron operating in the TE_16,2 mode. Radiation pattern results for the optimum launcher length agree well with theoretical calculations using the Stratton-Chu aperture radiation theory for unperturbed waveguide modes. A mirror focusing in the azimuthal direction was designed by a geometrical optics approach to focus the radiation coming from the launcher. Good focusing with 91.4% efficiency (power in the focused beam divided by gyrotron power) was found experimentally using the combined launcher and mirror with the pulsed gyrotron. These results indicate that quasi-optical antennas are useful for transforming high order, high frequency gyrotron modes into directed beams in free space.     

Design of a Quasi-Optical Mode Converter for a Frequency Step-Tunable Gyrotron

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 TE_17,6 at 105 GHz to TE_23,8 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.     

95 GHz回旋管内置准光模式转换器仿真设计

 高功率毫米波回旋管输出的高阶模式不利于空间传输,必须进行模式转换。由于不便采用波导模式转换器,因此对内置准光模式转换器进行了研究。内置准光模式转换器由Vlasov辐射器、准抛物柱面镜和相位修正镜组成。基于标量衍射理论和KSA算法,编制了数值模拟程序,设计了相位修正镜。计算分析了参考平面处的场分布,表明该准光模式转换器的标量转换效率大于98%,矢量转换效率大于93%。计算结果表明,该方法可以高效地指导准光模式转换器的设计。     

A High Efficiency Launcher and Mirror System for Use in a 110 GHZ TE22,6 Mode Gyrotron

A four-mirror internal quasi-optical mode converter designed for a CPI gyrotron is discussed. Many improved methods were used in designing the mode converter. The launcher was designed and analyzed using the TOL and Surf3d codes developed by CCR. Mirrors 1 and 2 were designed using analytic surfaces to shape the general wavefront curvature of the beam radiated from the launcher. Mirrors 3 and 4 were iteratively designed using improved techniques that produced smooth mirror surfaces. Good agreement was found between theory and low-power cold-test measurements. The fraction of power coupled between the target Gaussian beam and the output of mirror 4, inferred from measurements, was 0.990. The stray radiation from the internal quasi-optical mode converter, inferred from measurements, was only 1.9% of the total power radiated from the launcher. This resulted in a high overall system efficiency of 97.0%, which is greater than previous designs.     

Asymmetrical mirror optimization for a 140 GHz TE_(22,6) quasi-optical mode converter system

We introduce an asymmetrical mirror design to a 140 GHz TE_(22,6) quasi-optical(QO) mode converter system to correct the asymmetry of the beam's field distribution caused by the Denisov launcher. By such optimization, the output beam with better symmetrical distribution is obtained at the system's output window. Based on the calculated results,the QO mode converter system's performance is already satisfying without iterative phase correction. Scalar and vector correlation coefficients between the output beam and the fundamental Gaussian beam are respectively 98.4% and 93.0%,while the total power transmission efficiency of the converter system is 94.4%. The assistance of optical ray tracing to the design of such QO mode converters is introduced and discussed as well.     

95 GHz准光模式转换器实验研究

介绍了采用95 GHz准光模式转换器将TE62模式转换为高斯波束的实验测试结果。准光模式转换器由螺旋切口的Vlasov辐射器、一个准抛物柱面反射镜和两个相位修正镜组成。将半径5.62 mm圆波导内的TE62模式转换为束腰直径22.4 mm的高斯波束。实验采用毫米波天线近场扫描测试系统测试,实验结果表明标量转换效率大于97%,矢量转换效率大于88%     

W波段TE62-TEM00准光模式变换器

对准光模式变换器的基本理论和设计方法进行了讨论.以改进型等效电流理论为基础给出了Vlasov辐射器的分析方法,建立了数值模型,并进行了计算分析.继而推导了自适应相位修正Katsenelenbaum-Semenov算法,编制了相位修正反射镜自适应设计分析程序.在上述理论工作的基础上,针对3 mm波段TE62至TEM00准...