双共焦波导回旋行波管高频结构的电磁特性研究

研究了双共焦波导回旋行波管高频结构的电磁特性。根据惠根斯原理的光衍射理论,分析得出双共焦波导中的两类本征模式（叠加模和环形模）对应的截止频率和场分布情况。理论分析结果与商用仿真软件CST的仿真结果一致。其中用作回旋行波管工作模式的“反相叠加TE₀₆模”的损耗明显小于其他模式,这种不同模式损耗不同的特性将有效抑制竞争模式带来的寄生振荡。双共焦波导的模式密度略大于传统单共焦波导的模式密度,但是明显小于圆波导的模式密度,因此双共焦波导适合用作回旋行波管的高频结构。     

PBG波导基模特性的替代研究方法

论证了光子带隙(PBG)的约束模的性质是可以用波状波导来代替它进行分析的,这种替代法在PBG波导的设计中是很有用的,也有助于我们对不同类型波导间的藕合的理解和分析。     

PBG波导基模特性的替代研究方法

论证了光子带隙(PBG)的约束模的性质是可以用波状波导来代替它进行分析的，这种替代法在PBG波导的设计中是很有用的，也有助于我们对不同类型波导间的藕合的理解和分析。     

一种同轴波导TE01模到圆波导TE02模变换器的数值模拟

该文对一种同轴波导TE01(°)模到圆波导TE02(°)模变换器进行数值模拟研究.通过分析同轴波导与圆波导对接产生的模式转换效果,探讨尖劈模式变换段改善工作模式转换系数和工作频带以及抑制寄生模式的作用.利用Ansoft HFSS对模型进行的数值模拟计算结果表明,这种结构能够实现最大将89.3%输入信号能量转换到TE02(°)模,-3dB带宽约820MHz,带内对主要干扰模式TE01(°)的抑制在10dB以上.     

背脊波导移相器高次模特性研究

背脊波导移相器可以明显提高差相移效率,已引起广泛重视。对这种移相器的高次模特性研究得还不很彻底。本文采用行波展开法研究了这种器件的高次模特性,并指出背脊波导移相器无法令所有高阶模式都截止,但通过合理设计可以让高次模与主模的耦合很小,达到尽量减小高次模的目的。     

EAST 装置电子回旋共振加热系统波纹圆波导研究*

在EAST装置上正在建设140GHz/4MW/1000s电子回旋共振加热(ECRH)系统,单个回旋管输出的1MW功率通过波纹圆波导传输到天线聚焦镜上,然后经天线反射镜进入等离子体。运用表面阻抗法对波纹圆波导进行了理论分析,针对EAST装置ECRH系统需求的140GHz波纹圆波导进行了设计研究,所设计的波导传输模式为HE11模,具备1MW连续波运行能力且欧姆损耗低于0.02d B/100m,同时分析了HE11模在波导口外辐射模式及其与TEM00模耦合特性。     

高功率馈源设计研究

在分析高斯场与规则波导模式关系的基础上,分别运用数值求解耦合波方程和级连模匹配技术计算了圆波导H11模在不同形状渐变张角喇叭传输过程中与高次模式的耦合过程。在大量计算分析的基础上选择了其中一条曲线加工了实验馈源,利用实验和仿真的结果验证了数值模拟程序的正确性,从实践上确认了利用耦合波理论和模匹配技术设计高功率光滑变张角圆锥高斯馈源的可行性,为进一步分析设计实用型高功率高效率馈源打下了基础。     

太赫兹波导传输中的模式稳定性

太赫兹波在基模波导中传输的欧姆损耗很大,因此在传输太赫兹波时经常采用过模传输的方式来降低传输损耗。但采用过模传输,会引起波导中传输模式的变化,因此如何保证传输中的模式稳定是过模传输中的重要问题。本文采用仿真与实验的方法,对220 GHz圆传输波导中的圆波导半径渐变情况下的模式稳定性进行了研究。结果表明,适当延长渐变波导长度,可以抑制模式耦合,保持单模传输。     

多模圆同轴波导辐射器的研究

本文研究了多个高次模同时工作的圆同轴波导辐射器,推导出了辐射场计算公式,讨论了波瓣等化的模比值,推导出了圆同轴波导中的台阶所激励的E_(11)模对于H_(11)模的模比的计算式,并给出了典型数表。     

1维方形掺杂光子晶体波导中缺陷模的色散特性

为了研究1维方形掺杂光子晶体波导中缺陷模的色散,采用特征矩阵的方法研究了1维方形掺杂光子晶体波导中TE波和TM波缺陷模的变化特征,得到了TE波和TM波的缺陷模随色散强度、色散厚度变化的结果。结果表明,色散强度和色散厚度都会对1维方形掺杂光子晶体波导中TE波和TM波的缺陷模产生明显的影响;利用TE波和TM波的缺陷模随色散强度、色散厚度的变化规律,可以有效地实现对1维方形掺杂光子晶体波导中TE波和TM波各传输模式的有效控制。     

Uniplanar one-dimensional photonic-bandgap structures andresonators

This paper presents uniplanar one-dimensional (1-D) periodical structures, so-called photonic-bandgap (PBG) structures, and defect high-Q resonators for coplanar waveguide, coplanar strip line, and slot line. Proposed uniplanar PBG structures consist of 1-D periodically etched slots along a transmission line or alternating characteristic impedance series with wide band-stop filter characteristics. A stop bandwidth obtained is 2.8 GHz with a stopband rejection of 36.5 dB. This PBG performance can be easily improved if the number of cells or the filling factor is modified in a parametric analysis. Using uniplanar 1-D PBG structures, we demonstrate new high-Q defect resonators with full-wave simulation and measured results. These structures based on defect cavity or Fabry-Perot resonators consist of a center resonant line with two sides of PBG reflectors. They achieve a loaded Q of 247.3 and unloaded Q of 299.1. The proposed circuits should have many applications in monolithic and hybrid microwave integrated circuits     

A novel TEM waveguide using uniplanar compact photonic-bandgap(UC-PBG) structure

A novel waveguide using a photonic bandgap (PBG) structure is presented. The PBG structure is a two-dimensional square lattice with each cell consisting of metal pads and four connecting lines, which are etched on a conductor-backed Duroid substrate. This uniplanar compact PBG structure realizes a magnetic surface in the stopband and is used in the waveguide walls to provide magnetic boundary conditions. A relatively uniform field distribution along the cross section has been measured at frequencies from 9.4 to 10.4 GHz. Phase velocities close to the speed of light have also been observed in the stopband, indicating that TEM mode has been established. A recently developed quasi-Yagi antenna has been employed as a broad-band and efficient waveguide transition. Meanwhile, full-wave simulations using the finite-difference time-domain method provide accurate predictions for the characteristics of both the perfect magnetic conductor impedance surface and the waveguide structure. This novel waveguide structure should find a wide range of applications in different areas, including quasi-optical power combining and the electromagnetic compatibility testing     

PBG结构缺陷的谐振特性研究

本文研究了矩形波导中利用介质层PBG结构形成的Fabry-Perot谐振器的特性，并详细分析了PBG结构的纵向长度、谐振区长度以及介质层介电常数对其谐振特性的影响。本文以制作此类谐振器具有一定的参考价值。     

声光可调谐滤波器中波导与模分离器的设计

声光可调谐滤波器（AOTF）是一种基于集成光学技术的光学器件,它的性能主要取决于它的各个关键模块,特别是光波导和模分离器的设计．首先采用有效折射率法设计了工作于1．55um处的Ti：LiNbO3单模波导,之后对所设计波导的模场进行了模拟,并对模拟结果进行了分析．在单模光波导设计的基础上,采用光束传播方法（BPM）设计了TE／TM模分离器,并分析了它的消光比．最终得出波导和模分离器的优化设计结果．     

Large negative dispersion in square solid-core photonic bandgap fibers

In this paper, a Ge-doping square solid-core photonic bandgap (PBG) fiber is proposed and the effective index of defect mode is investigated. Simulations show that, at the starting wavelength of the defect mode, n/sub effd/ (the effective index of defect mode) changes rapidly due to the PBG effect, which induces large negative dispersion in fiber. This mechanism is different from the mode coupling case in dual-core concentric fibers, and the dispersion characteristic is more robust to structural deviations.     

UC-PBG结构创建准TEM波导的仿真分析

光子带隙(Photonic BandGap, PBG),是指人造的周期性电介质结构,它使得在一定频率范围内的电磁波是禁止传播的,而单平面紧凑型光子带隙结构(UC-PBG)是一种以微带基片为载体的周期性平面光子带隙结构。该文用UC-PBG结构置换标准矩形波导窄边,可在UC-PBG结构的谐振频率点附近将TE10模转变成准TEM模。通过对整个系统进行仿真计算,证实了此方法切实有效,在Ku波段转换带宽达到450 MHz。     

Photonic bandgap dielectric waveguide filter

The application of photonic bandgap (PBG) structures as the sidewall of the printed circuit board (PCB) dielectric waveguide filter is investigated. The effect of different PBG parameters on the Q-value of PBG dielectric waveguide resonator is evaluated. A PBG dielectric waveguide three-pole Chebyshev bandpass filter is realized. The measured performance matched well with the calculated results. The newly proposed I/O coupling structure makes the filter much easier for mass production     

一种有效解决较宽频带电源完整性问题的方法

光子能带隙结构能够有效解决高频（0．4GHz以上）的电源完整性问题,去耦电容能有效解决低频（0．4GHz以下）的电源完整性问题。文章介绍了一种结合光子能带隙结构和去耦电容解决电源完整性问题的方法,并利用Ansoft公司Siwave软件仿真分析。     

共面紧凑型微波光子晶体在共面波导中的应用

提出一种地平面刻蚀共面紧凑型微波光子晶体(PBG)的共面波导结构,介绍了微波光子晶体的基本单元结构,并设计出具有90°弯折的共面波导样品.使用矢量网络分析仪测试该结构的散射参数,测量结果显示,其传输特性比普通的共面波导在高频部分具有较大的提高.同时,相比于传统的三维微波光子晶体,该结构具有导体损耗小,加工工艺简单,便于应用于光电封装和单片微波集成电路的特点.

Abstract：

A novel coplanar waveguide using coplanar compact microwave photonic-handgap (PBG) structure is proposed. The basic unit of microwave PBG structure is introduced and a waveguide sample with a 90 degree break is designed. Testing results obtained through vector network analyzer display an obvious promotion in transmission parameter, especially in the high frequency part. Meanwhile, compared with the common 3-dimension microwave PBG structure, this structure with a low conductor loss can be processed with standard planar fabrication technology, which makes it applicable in opto-electronic package and monolithic microwave integrated circuit (MMIC).     

矩形波导TE10模的仿真与分析

针对矩形波导TE10模的特点,为了提高电磁设计性能,设计出矩形波导TE10模的仿真模型。本文首先根据电磁场传播理论,采用直角坐标系分析对无源自由空间电场和磁场采用矢量亥姆霍茨方程分析,得出矩形波导中传输模式及其场分布,然后分析了矩形波导中传输模式的纵向传输特性,最后利用HFSS软件对矩形波导TE10模的场结构进行三维空...