大功率圆波导旋转铰链的设计与仿真研究

着重对圆波导旋转铰链的主要尺寸(圆波导半径R、圆波导腔体长度L、模式变换块厚度和高度以及圆波导铰链输入口径)进行了理论设计和分析,给出了工程经验设计公式,并借助于微波电磁场仿真软件HFSS,对Ku、X波段两种圆波导旋转铰链进行了仿真设计,理论上拓宽了圆波导旋转铰链的工作带宽。结果和目前该两种圆波导旋转铰链产品实测性能比较吻合。     

8-18GHz同轴-波导转换器的分析与设计

同轴-波导转换器是微波系统中非常重要的元器件.基于脊波导和波导阶梯对导播系统中电磁波传播性能的影响,本文探讨了这两种结构应用在8-18GHz的宽带同轴-波导转换器设计中的情况.通过同轴-脊波导-矩形波导转换,并在脊波导上加载阶梯,很好地改善了阻抗匹配效果,提高了同轴-波导转换器的传输性能.仿真结果证明脊波导和波导阶梯在设计同轴-波导转换器中的有效性,在8-18GHz的倍频程带宽内驻波小于1.22,产生的高次模非常小.     

天线馈电与馈电设备

0620153周期性结构在毫米波波导同轴转换中应用[刊,中]／周焱／／北京航空航天大学学报．-2006,32(4)．-412- 416(L)波导同轴转换连接器是微波、毫米波通信和测试中非常重要的器件。基于PBG和阶梯阻抗变换结构在导波系统中对电磁波传播性能的影响,探讨和研究了将这2种周期性结构应用在8mm波导同轴转换连接器的设计中的情况,通过在同轴腔内导体介质支撑垫中布置二维PBG结构抑制同轴部分横向溢散的电磁波,通过在波导腔体内增加阶梯阻抗结构,改善阻抗变换效率,提高波导同轴转换器件的传输性能。参10     

波导—同轴转换器国内外的新进展

本文对波导－同轴转换器，尤其是毫米波波导－同轴转换器的发展进行了综述，介绍了国外该转换器的新技术和主要性能。     

毫米波TE62准光模式产生器的研究

介绍了准光激励旋转TE62模式产生器的工作机理。采用准光学系统对腔壁带有小孔的谐振腔激励,在毫米波段实现高斯基模转换到旋转TE62模式的转换。重点对腔壁带有小孔的同轴腔体谐振腔内部场结构进行了分析。研究了同轴比对模式分离的影响以及如何选取,提高模式转换器的效率和模式转换纯度。设计了在频率96.4 GHz附近同轴圆波导旋转TE6 2模式激励器。并对装置采用毫米波近场自动测试系统进行实测,模式纯度达到97%。     

W波段低电压宽带过模矩形同轴曲折波导行波管的研究

提出了一种具有高频率、宽频带和低电压特点的矩形同轴曲折波导慢波结构,所提出的矩形同轴曲折波导工作于过模状态,工作频率较高,同时具有不错的传输特性。设计了一种宽带的双脊加载的波导-同轴转换器,其带宽可以覆盖矩形同轴曲折波导行波管的整个工作频带。所设计的矩形同轴曲折波导行波管工作电压和电流分别为3230 V和150 mA,慢波结构长度为32 mm,PIC仿真结果表明,在76～110 GHz频率范围内,其输出功率超过13.7 W,在108GHz频点,输出功率达到最大值,约为27.4 W,对应的射频效率为 5.65%。     

Matlab求解方同轴波导的截止波长和特性阻抗

采用有限差分法利用Matlab求解了方同轴波导的特性阻抗和高次模的截止波长并画出了场结构图,将所得数据与国外文献数据进行了对比,证明了有限差分法结合Matlab在分析简单截面的同轴波导时是简单可行的,而且计算精度较高,通用性强,可以用于传输线工程问题的设计和计算.最后计算了矩形同波导和偏心同轴波导的相关数据,用于与方形同轴波导对比.     

W波段低电压宽带过模矩形同轴曲折波导行波管的研究（英文）

提出了一种具有高频率、宽频带和低电压特点的矩形同轴曲折波导慢波结构,所提出的矩形同轴曲折波导工作于过模状态,工作频率较高,同时具有不错的传输特性。设计了一种宽带的双脊加载的波导-同轴转换器,其带宽可以覆盖矩形同轴曲折波导行波管的整个工作频带。所设计的矩形同轴曲折波导行波管工作电压和电流分别为3230 V和150 mA,慢波结构长度为32 mm,PIC仿真结果表明,在76～110 GHz频率范围内,其输出功率超过13.7W,在108GHz频点,输出功率达到最大值,约为27.4W,对应的射频效率为5.65%。     

无线电设备、电信设备

TN811,TN8142005040705一种新型同轴TEM-圆波导TE11模式变换器/刘庆想,袁成卫(西南交通大学理学院)//强激光与粒子束.―2004,16(11).―1421～1424.提出了一种新型同轴插板式模式变换器,可以实现同轴TEM到圆波导TE11模式的变换。介绍了这种模式变换器的工作原理:即通过在同轴波导中沿轴向插入金属板,将同轴TEM模变换成扇形截面波导TE11模,进而利用不同扇形截面波导中的相移改变电场分布的轴对称性,在同轴波导中形成同轴TE11模,最后将同轴TE11模转换为圆波导TE11模式。基于这一原理设计了一个中心频率为3.8GHz的同轴TEM-圆波导TE…     

微波源中同轴提取区支撑杆的理论分析与设计

同轴提取区支撑杆的设计是MILO等同轴提取型高功率微波源设计的重要环节。本文根据场匹配原理导出了具有支撑杆的同轴提取区系统的传输方程和散射矩阵，并对同轴提取区各部分的微波模式进行了理论分析。对给定参数下的同轴提取区系统的散射矩阵参数进行数值计算，进而得到各微波模式系数，并对支撑杆进行了设计和参数优化。理论分析和数值计算都得出同样结论：对一定频率的微波来说，若同轴波导中第一个截止模式是Hn1则应选择n根支撑杆。这种支撑杆对TEM波的传播几乎无影响，可使微波源的束波互作用区及微波模式转换器和辐射器免受非旋转对称模式的影响。     

A multipole analysis of a dielectric loaded coaxial rectangularwaveguide

A multipole analysis of a coaxial rectangular waveguide whose inner conductor is circular is made in order to determine the TE and TM modes of the system. The analysis is based on using multipole (dipole, quadrupole etc.) electric and magnetic current sources to generate field solutions in the waveguide. These solutions are used to match the electromagnetic boundary condition in a homogeneous coaxial rectangular waveguide and to determine the TE and TM eigenvalues of the waveguide system. Eigenvalue results are compared with results of the generalized spectral domain method and to eigenvalue results for a ridged waveguide. Propagation in a coaxial rectangular waveguide is also studied when the coaxial rectangular waveguide is loaded with lossy inhomogeneous dielectric material. A variational formula is used to relate the TEM, TE, and TM modes of an empty coaxial rectangular waveguide to the propagation in the loaded inhomogeneous dielectric waveguide     

一种基于同轴波导的异向传输线

该文提出了一种基于同轴波导的新型异向传输线,与现有基于微带电路的异向传输线相比,这种结构有更高的工作频率、损耗较低和更大的功率容量;与基于同轴波导和矩形波导的异向传输线相比,其结构更简单容易实现。等效电路与有限元仿真的结果均表明这种结构在特定的频段表现出明显的异向特性。     

Rectangular Waveguides with Impedance Walls

The propagation of guided waves in a rectangular geometry having impedance boundary conditions is investigated. An impedance compatibility relation is derived that must be satisfied in order that a separable modal solution exists for a given impedance configuration. Several new rectangular waveguides are developed; among them are 1) a tall rectangular waveguide operating in a dominant H/sub 10/ mode with no H/sub 0N/ modes; 2) a rectangular waveguide with two parallel anisotropic impedance surfaces; 3) a rectangular waveguide with two parallel walls having isotropic impedance surfaces, the other two walls being anisotropic; 4) a rectangular waveguide supporting only E modes; and 5) rectangular coaxial systems containing impedance surfaces. The modal structure of rectangular waveguides with impedance boundary conditions offers advantages over the conventional waveguide. The potential of oversizing for low-loss and high-power applications is enhanced because of the additional modal control provided by the impedance surfaces. Other applications are suggested.     

2-port ?G/4 waveguide standard of voltage standing-wave ratio

A new calculable standard of voltage-reflection coefficient and voltage standing-wave ratio consists of a quarter-guide-wavelength section of waveguide having cross-sectional dimensions different from those of the waveguide system into which it is inserted. Design equations are given for waveguide of rectangular and coaxial cross-sections.     

毫米波车地通信的小型化波导螺旋阵列天线设计

高速磁浮列车毫米波车地通信系统要求其车载天线具有小型化、宽频带、圆极化和辐射扇形波束等特点。为更好地满足这些要求,设计一种中心馈电的小型化波导螺旋阵列天线。该天线馈电系统采用同轴波导中心馈电、4路矩形波导并馈的形式,通过改变馈电波导尺寸、耦合探针长度以及末端采用波导同轴转换器等形式,实现了所有单元的等幅馈电;天线单元由低剖面螺旋天线构成,采用顺序旋转技术改善天线的圆极化性能。利用全波电磁仿真软件设计了一款中心频率为38 GHz的28单元波导螺旋阵列天线,并进行了实验测试。测试结果表明：在37~39 GHz频带范围内,天线驻波比小于1.41,增益大于21.7 dB,轴比小于3.6 dB,俯仰面波瓣宽度为4.5°~4.7°,方位面波瓣宽度为29°~29.7°,满足毫米波车地通信系统车载天线的设计需求。     

Analysis of an End Launcher for an X-Band Rectangular Waveguide

The analysis of an end-launcher type, coaxial-to-rectangular waveguide transition, exciting dominant TE/sub 01/ mode in X-band rectangular waveguide is presented. Expressions for the real and imaginary parts of the input impedance seen by the coaxial line are derived for the general case of an offset launcher using self-reaction of an assumed current over the loop. The dimensions of the combined electric and magnetic loops having low input VSWR in the coaxial line are determined. There is satisfactory agreement between theoretical and experimental results.     

门钮式同轴TEM——矩形TE_(10)微反射过渡结构

基于门钮窗结构设计适合高功率微波传输的同轴TEM模——矩形TE10模的微反射过渡结构,经优化后,此类过渡结构在L波段驻波比小于1.1的相对带宽超过4%。在同轴线中增加感性销钉后,此类微反射过渡结构可以与另一段同轴线构成多节带通滤波器。研究表明:感性销钉取向对过渡结构的通带有重要影响,只有沿平行于矩形波导方向插入销钉才能得到最宽的通带。     

The input impedance of a hollow-probe-fed, semi-infiniterectangular waveguide

Image theory is used to determine the input impedance of a coaxial feed in a short-circuited, semi-infinite, rectangular waveguide. The analysis is applicable to hollow antenna probes of variable height and lends itself well to accurate numerical evaluation. The numerical results are compared to results obtained from other methods and show the efficacy of using image theory to determine the waveguide input impedance     

Mode Selective Coaxial Directional Couplers for Harmonic Measurements

Bethe's small-hole coupling theory is applied to coaxial transmission line to design mode selective directional couplers. By independently sampling the TEM and TE11 modes in coaxial line, harmonic measurements can be performed which would require five or more directional couplers if made in rectangular waveguide. Mode selectivity on the order of 30 dB has been achieved.     

Cylindrical antenna in a rectangular waveguide driven from a coaxial line

The problem of a cylindrical antenna in a rectangular waveguide driven from a coaxial line, where the antenna spans the entire guide height, is analysed, and the admittance evaluated. An experimental investigation shows the theory to be very accurate.