94GHzTE6,2模内置准光模式变换器

提出了可应用于94 GHz回旋管内部的TE6,2准光模式变换器.根据几何光学和矢量绕射理论编制了模拟其电磁行为的分析和优化程序.根据几何光学原理,设计了该模式变换器的初步结构参数,然后利用该优化程序获得了最优化的相关参数.优化结果表明,在94 GHz,该准光变换器功率转换效率约为85%,转换所得波束高斯含量高于70%.     

太赫兹宽带Denisov型准光模式变换器的设计分析

研究并设计了一种具有宽频带工作能力的太赫兹准光模式变换器。该准光模式变换器采用具有高效率特性的Denisov 辐射器,工作在TE_6,2模式,用于实现回旋管内的模式变换。由于Denisov 辐射器的参数是影响准光模式变换器宽带性能的主要因素,因此通过对辐射器参数的优化设计,达到增大模式变换器带宽的效果。使用自主开发的准光学模拟程序进行仿真,模式变换器中心频率为94 GHz,带宽达2 GHz。     

170 GHz回旋管准光模式变换器的设计

针对170 GHz回旋管研究,设计了一种高效Denisov准光模式变换器,该回旋管工作在模式。模式变换器由微扰结构的辐射器和镜面系统组成。基于耦合模理论和矢量绕射理论,研究了两级微扰辐射器,优化设计了镜面系统。仿真结果显示,模式转换为高斯光束,其输出功率转换效率为93.7%。     

A high-efficiency quasi-optical mode converter for a 140-GHz 1-MW CW gyrotron

A highly efficient quasi-optical mode converter system with several novel features has been designed and tested at Forschungszentrum Karlsruhe (FZK). The converter consists of a dimpled-wall waveguide launcher, one quasi-elliptical mirror and two toroidal mirrors. The coupled-mode theory has been used to analyze the operation of the prebunching waveguide launcher; the radiated fields from the cut of the launcher have been calculated by the scalar diffraction integral. Simulation results show that the advanced dimpled-wall launcher generates a well-focused Gaussian radiation pattern with low diffraction losses. In this case, toroidal mirrors are sufficient to obtain a desired output beam pattern. An efficiency of more than 98% has been achieved to convert the rotating TE/sub 28,8/ cavity mode at 140 GHz into a fundamental Gaussian beam. Experimental measurements show close agreement with theoretical predictions.     

Experimental study of a high efficiency quasi-optical mode converter for whispering gallery mode gyrotrons

A mode converter for whispering gallery mode gyrotrons has been designed and experimentally demonstrated. Experiments were performed on a megawatt power level, 3μs pulsed gyrotron operating in the TE_16,2,1 whispering gallery mode at 146 GHz. The gyrotron cavity employs a non-linear uptaper to minimize radial mode conversion. About 99% of the output power is in the TE_16,2 mode. The quasi-optical converter consists of a helically cut Vlasov-type waveguide launcher and a reflector. The doubly curved reflector, designed using geometric optics and vector diffraction theory, was built to focus the full radiation pattern to a small, gaussian-like focal spot. Of the power incident in the TE_16,2 mode, 96% is directed by the launcher and reflector to a gaussian-like focal spot in the far field. Small fractions of other modes were found to form distinct focal spots in the far field. Analysis of the power in the other focal spots allows for a good quantitative measurement of gyrotron output mode content, potentially on a single shot basis.     

W波段准光模式变换器的优化仿真设计

以准光近似理论为基础,建立了输入模式为TE03模、频率为94GHz的准光模式变换器模型,并进行仿真优化设计,得到了优化后的准光模式变换器数模型参数;仿真结果表明辐射波束具有明显的方向性,波束明显变窄锐化,主瓣增益很高,达到29.46dBi,能量主要集中在主瓣上,旁瓣增益较低,辐射效率达到87.36%,当输入端口波导直径为9mm的准光模式变换器时,其功率的容量超过了300MW.     

94 GHz回旋管准光模式变换器的数值模拟

对回旋管内置准光模式变换器进行了理论研究和数值模拟。基于几何光学理论和矢量绕射理论,编制了模拟电磁场行为的分析和优化程序,采用Vlasov辐射器和准光反射器实现了线极化准高斯模HE11。结果表明:在一级反射镜下的转换效率为88.3%,增加反射镜级数会降低转换效率。     

Experimental study of a quasi-optical cavity with slotted output mirror

This paper describes an experimental study of a quasi-optical cavity to be used in qyrotrons. The cavity configuration was designed so that its output wave could pass into a quasi-optical transmission line. The test cavity was coaxially composed of a pair of annular mirrors, one of which was a curved conical mirror and the other was a plane mirror having a radial slot array for wave output. A mode excited in the cavity at 56.4 GHz was observed by detecting the radiation wave that leaked out through the slotted mirror. It was shown that the present slotted mirror served as a partially and uniformly transparent mirror to radiate the output wave with the same mode as in the cavity.     

Experimental study on a quasi-optical mode converter for transforming the whispering-gallery mode into a circularly polarized hollow radiation beam

An experiment was carried out for transforming the 120 GHz-TE_12.2 whispering-gallery mode (WGM) into a circularly polarized hollow radiation beam. A hollow beam was formed by reflecting the WGM, which was radiated from a 16 mm radius circular waveguide cut, with an annular mirror having suitable local normal vectors. The experimentally observed field intensity profiles of the reflected wave were in good agreement with calculated results.     

TE22,6模式—高斯波的准光模式转换器设计

准光模式转换器是高功率毫米波回旋管的重要组成部份,能够实现电磁波与电子注的分离、隔离波的反射,并实现回旋管的高斯波束输出。基于耦合波理论,分析设计出用于频率140 GHz、TE22.6模式回旋管的Denisov辐射器;基于几何光学理论,设计出准光反射镜面系统,并采用Feko软件进行优化。计算结果表明,所设计的准光模式转换器系统的转换效率约为97.3%,波束的高斯含量约为93.3%,达到了回旋管的应用需求。     

Ka波段准TE01模椭圆型准光模式变换器的理论修正与设计

基于圆电模研究了椭圆型准光模式变换器，并提出用于快速设计椭圆结构准光系统的修正公式。利用修正公式设计的准光系统由椭圆型Vlasov辐射器与准抛物面镜组成。计算仿真结果表明，该椭圆体系所辐射的波束具有辐射方向性更好，副瓣增益更低的特性，并且其尺寸相比于传统的圆体系更小。     

Bernstein mode quasi-optical gyroklystron

The performance of a quasi-optical cyclotron harmonic gyroklystron operating on electron Bernstein modes is investigated. An expression for the linear power output has been derived. It is found that, for high order cyclotron harmonic operation, a gyroklystron involving the Bernstein modes has higher linear efficiency than a corresponding gyroklystron based on electromagnetic interactions alone.     

140 GHz回旋管高转换效率准光模式变换器设计研究（英文）

成功实现高转换效率的140 GHz TE22,6准光模式变换器原型设计。基于周期微扰原理设计Denisov辐射器,实现低边缘绕射的初级出射波束。针对三镜面光路系统,采用全矢物理光学积分作为主要计算手段,围绕主极化场分量进行三级相位修正面迭代优化,实现高出射高斯纯度的模式场转换,其中一级镜的修正有效改善了辐射器出射的不理想性。基于全矢数值仿真确认,相比原二次曲面原型设计,相位修正后的变换器系统的出射高斯纯度从92.7%提高到99.6%,结合98.8%以上的功率传递效率,实现了性能优越的高阶回旋管准光模式变换器原型设计。     

Design of a quasi-optical mode conversion system with variable output beam size

The quasi-optical system consisting of a quasi-optical antenna and two parabolic mirrors can convert the TE₀₃ mode output (f = 301 GHz) of the Gyrotron FU IV into a well collimated, linearly polarized beam. This system offers the possibility of tuning the size of the beam produced from 5 mm up to 24 mm by rotating and moving the two parabolic mirrors.     

Mirror synthesis for gyrotron quasi-optical mode converters

A new approach for the design of a quasi-optical gyrotron mode converter is proposed. It is based on the synthesis of quasi-optical mirrors using diffraction (Helmholtz-Kirchhoff) integrals. First application of such a method we already described in [1, 2]. Now a more powerful technic is used to provide optimal distributions of the wave beam field. It is shown that by means of specially shaped mirrors parameters of the main converter are enhanced strongly. In this paper we review the search for the optimal scheme of the converter, present and compare results of calculations and measurements of the gyrotron wave beam.     

94GHzTE5,3准光辐射器

基于耦合波理论和相位匹配技术,对准光辐射器的传统设计方法进行了改进,使其适用于低阶模式的设计.通过调节耦合时模式间的相位,在切口处实现了具有高斯场分布的理想模式组合.利用这一方法,优化设计了一个94 GHz,TE5,3回旋管准光辐射器.数值模拟结果表明,设计的辐射器在切口处形成了一个良好的束斑,边馈电平达到-30 dB,口径场高斯含量高于98%.     

一种平均电流模式控制的单电感双输出型开关电源转换器

An integrated single-inductor dual-output （SIDO） switching DC-DC converter is presented. The outputs are specified with 1.2 V/400 mA and 1.8 V/200 mA. A decoupling small signal model is proposed to analyze the multi-loop system and to design the on-chip compensators. An average current control mode is introduced with lossless, continuous current detection. The converter has been fabricated in a 0.25μm 2P4M CMOS process. The power efficiency is 86% at a total output power of 840 mW while the output ripples are about 40 mV at an oscillator frequency of 600 kHz.     

A single-inductor dual-output switching converter with average current mode control

are about 40 mV at an oscillator frequency of 600 kHz.     

A five-order mode converter for multimode waveguide

A numerical model of five-order mode converter that converts the order of modes in an integrated-optic multimode waveguide is proposed. Such a structure is useful in optical guiding wave devices for mode control and mode shuffling. The dimensions and index profile of the device are well within the capabilities of the state of the art of integrated optics technology. We have successfully optimized the structural design of the device for propagation loss of less than 13.1 dB at an operating wavelength of 1.55 /spl mu/m. A cascaded form of the five-order mode converter is also proposed for selective mode conversion without the need of restructuring the connection within the device.     

Calculation of radiation from a quasi-optical reflector antenna for whispering gallery mode

We propose a method to calculate the radiation characteristics of a quasi-optical reflector antenna for whispering gallery mode called Vlasov's antenna. Correction of the shape of the reflector, which was a parabolic cylinder in the original paper by Vlasov et al. (1975), is performed using wave-normal rays. The radiation field is calculated by means of an image source which is obtained with the geometrical optics. Some numerical results show that the radiated beam is gaussian-like in far zone. A scheme of high-power application (500kW, 106·4GHz, TE_12,2) to a beam transmission system is also presented