具有双槽结构模变换器的双频段波纹喇叭

从双频段波纹喇叭的辐射特性出发,确定了喇叭的口面参数,设计了喇叭的辐射段、变角段和光壁过渡段,并用球面波展开法计算其辐射方向图。研究了双槽结构模变换器不同的角度对喇叭的回波损耗、辐射特性及工作带宽的影响。设计了Ku/Ka双频段波纹喇叭,E面和H面辐射方向图保持良好的等化,回波损耗在Ku频段优于22 dB,在Ka频段优于30 dB。     

一种宽频带圆锥波纹喇叭设计

设计了一种工作频带范围为22-30GHz 的圆锥波纹喇叭。通过电磁场仿真软件HFSS 对该天线进行仿真,计算了天线的驻波系数、交叉极化、增益方向图、相位中心等参数。计算结果表明,该波纹喇叭方向图对称性好、交叉极化低,可用作高性能反射面天线馈源。     

一种新颖L/C双频段波纹喇叭模变换器

提出和研究了一种新颖的用于L/C双频段共用波纹喇叭的双槽结构模变换器。这种双槽结构是由一个环加载槽和一个直槽组成。实验结果表明,一个拥有该新颖双槽结构模变换器的波纹喇叭可在L/C双频段内提供良好的匹配和对称的辐射方向图。     

宽带多波束发射阵的误差分析与性能测试

给出一维多波束发射阵的功率方向图和等效辐射功率表达式,并采用数值计算方法,对喇叭存在幅度、相位误差,阵元失效时发射阵功率方向图各项指标的变化进行仿真计算,得出一些有益于发射阵设计和维护的理论指导结论。最后对正常情况和部分阵元失效时的功率方向图及等效辐射功率进行测试比较,实测结果与理论计算的趋势完全一致。     

双频段共用圆锥波纹喇叭的设计研究

本文详细地研究了双频段共用圆锥波纹喇叭的设计方法,特别是模转换器的设计。文章还讨论了这类馈源交叉极化的计算和控制措施。     

基于CMA-ES优化方法的波纹喇叭优化技术

介绍了旋转体时域有限差分法(BOR-FDTD),导出了电磁场迭代计算公式。给出了自适应协方差矩阵进化策略(CMA-ES)的基本原理和步骤。提出了一种基于BOR-FDTD和CMA-ES的波纹喇叭优化设计技术,并将该项技术用于平方公里阵(Square Kilometre Array,SKA)望远镜天线Band 4(2.8~5.18 GHz)波纹喇叭馈源的优化设计。计算结果表明,该馈源在工作频带内反射损耗基本在-20 d B以下,天线口径效率均优于86.5%,且口径效率随频率的变化较小。     

L/S/C三频段波纹喇叭耦合L频段差模的研究

在具有单脉冲跟踪能力的超宽带双槽深波纹喇叭的研究中,通过对双槽深波纹喇叭内的差模临界截止点和电压波腹点的研究和分析,提出了在双槽深波纹喇叭内耦合出差模信号的思路,并据此设计了在L频段具备单脉冲跟踪能力的L/S/C三频段共用双槽深波纹喇叭.通过理论计算、仿真和测试,该设计在L/S/C三频段具有良好匹配特性,辐射方向图对称,耦合出的L频段差模信号实现了单脉冲跟踪能力,天线性能达到了预定目标,验证了设计方法的有效性.     

采用非线性最小二乘法实现双频圆形天线阵的方向图综合

研究了20GHz和30GHz双频段圆环阵列天线的方向图综合方法。采用了非线性最小二乘法对影响天线方向图的诸多参数，如单元的幅度和相位、单元间距以及单元在阵中的位置进行优化设计，以使双频段阵列方向图在最小二乘意义上逼近预先给定的理想方向图。仿真结果表明该方法可行、有效。     

高性能C,X宽频带双频馈源设计

介绍了高性能Ｃ、Ｘ双频段双槽深波纹喇叭及超宽频带正交器的设计方案及其调度并给出馈源系统主要性能测试结果。     

4／6GHz双频段800MHz宽频带波纹喇叭

本文论述了Ｃ波段双频段８００ＭＨｚ宽频带波纹喇叭的设计。     

N槽结构波纹喇叭的理论分析

本文利用空间谐波法导出了N槽结构(每个周期有N个槽)波纹喇叭的特征方程和等效壁导纳的普遍公式,并把这些公式应用于双槽深波纹喇叭,给出了其等效壁导纳的表达式。文章还对一个双槽深波纹喇叭的等效壁导纳、特征值、口面模比和辐射方向图进行了数值计算,并与实验结果比较,两者吻合得很好。     

初级馈源的高斯波束描述

通过对高斯波束基本理论的分析,描述了3种常用高斯模(主模、差模和交叉极化模)的表达式及特征。以此为依据,详细分析了波纹喇叭横向电场表达式以及计入反射面损失的喇叭辐射场,论述了如何用高斯模表示喇叭口面场,并具体列举了平衡混合状态下波纹喇叭口面场特征参数的求解过程,以及喇叭口面场高斯表示方式。     

Gain of corrugated conical horns

The absolute gain of a corrugated horn which is designed as a 100-GHz gain standard for the Crawford Hill 7-Meter offset reflector has been calculated and measured. The measured gain is determined from "three horn" transmission measurements. The other two horns are a TRG Model W869 corrugated horn and a dual mode horn. Correction factors were computed from the near field power transmission formula. The measured gain of the gain standard is30.8 pm 0.16 dB. Comparison between measured and calculated gains indicate very low ohmic loss in a corrugated horn. The condition of maximum gain for a given length has been found to be a half wavelength phase deviation in the horn aperture. Calculated gain data as well as near field correction factors for two identical corrugated conical horns are given here as reference information.     

Design of corrugated horns: a primer

Typical example of horn is shown where the inside wall is manufactured in a succession of slots and "teeth". The purpose of the corrugated surface is to provide the means to support the propagation of hybrid modes within the horn. Hybrid modes are basically a combination of TE and TM modes. Some basic information for the inexperienced horn designer to get started in designing their corrugated horn is provided. The class of circularly symmetrical corrugated horns and the parameters in designing are considered. As an example a standard Ku-band operation from a typical Earth station is also considered.     

波纹喇叭差模耦合点的分析

通过对波纹喇叭基本理论的分析,描述了波纹喇叭具有的特殊参数点(低频截止点、快慢波分界线、平衡混合条件、高频截止条件、短路条件)的表达式及特征。以此为依据,详细讨论了在波纹喇叭中主模HE11与差模HE21共存的条件,以及在波纹喇叭内的差模临界截止点的分析。通过寻找到电流或者是电压的波腹点,由此可以更准确选定好开耦合口的位置。     

C波段差模耦合波纹喇叭

通过对波纹喇叭基本理论的分析,描述了波纹喇叭特殊参数(低频截止点、快慢波分界线、平衡混合条件、高频截止条件、短路条件)的表达式及特征。通过对波纹喇叭内差模临界截止点的分析,找到电流或者电压的波腹点,更准确地选定开耦合口的位置。为了使差模信号反射小,主要考虑了波纹喇叭的HE21模式与矩形波导的TE10模式匹配、耦合孔与矩形波导的匹配,以此为依据,选择矩形波导尺寸和耦合孔的尺寸。利用Ansoft软件建立一个C波段波纹喇叭差模耦合模型,仿真计算结果与理论分析吻合,实物测试结果也与理论分析一致,证明了这种设计理论在工程应用中是可行的。     

具有L波段单脉冲跟踪能力的L/S双波段共用波纹喇叭天线

单脉冲跟踪以其精度高、速度快等优点而被广泛应用于跟踪中、低轨卫星通信天线中.本文工作研究单槽深波纹喇叭的差模临界截止点和电压波腹点,通过提取波纹槽差模信号,设计了具备L频段单脉冲跟踪能力的L/S双频共用喇叭天线.实际测试结果表明,在L/S频段该喇叭具有良好阻抗匹配特性和辐射方向图旋转对称特性,且L频段差模信号实现了单脉冲跟踪能力,该喇叭天线电气性能满足工程应用要求.     

Broadbanding of corrugated conical horns by means of the ring-loaded corrugated waveguide structure

Broadbanding of corrugated conical horns is investigated with the ring-loaded corrugated circular waveguide (RCWG) structure devised by the authors. The useful frequency bandwidth in which the corrugated horn is effective for the improvement of antenna properties is limited by the frequency characteristics of the horn-aperture field and input VSWR of the horn. By the precise analysis of the RCWG, the maximum frequency range in which the desirable field is obtained is much wider than that in the conventional corrugated circular waveguide, and is achieved almost independent of ring thickness, when ring width is about 20 percent of slot depth. The characteristic impedance of the RCWG is nearly equal to that of the homogeneous circular waveguide when ring thickness becomes large. Therefore, a good transformer between the RCWG and the homogeneous circular waveguide is achieved by increasing ring thickness from the RCWG toward the homogeneous waveguide. From the above investigations, it is found that in the ring-loaded corrugated horn, the useful bandwidth is 1.35 times broader than that in the conventional corrugated horn. The theoretical results are verified by the experimental results.     

Wideband linearly or circularly polarized monopulse trackingcorrugated horn

A design of a wideband monopulse tracking corrugated horn, for either a linearly or a circularly polarized signal, is presented. Two types of suppressors are introduced to restrain the excitation of unwanted higher order modes. Parametric dependence curves of special points on the propagation characteristics are given for m=1 and m=2 modes in the ring-loaded corrugated horn. By using the suppressor and employing ring-loaded slots in the entire horn, the cross-polarization peak level of the horn can be reduced by a further 10 dB or more in the transmitting band, and its maximum level is less than -28 dB across C-band. The experimental results of return loss and sum and difference patterns validate that the feed possesses satisfactory wide-band communication and tracking characteristics     

基于螺纹槽结构的90°波纹喇叭性能研究

为了拓宽宽带通信天线波纹喇叭馈源的工作频带，设计了一款新型90°波纹喇叭，它的波纹槽以阿基米德螺线的轮廓向外扩展. 仿真和测试结果表明:该新型波纹喇叭最优工作带宽可达2∶1，在10~20 GHz的工作频带内，具有稳定的相位中心，其45°面最大交叉极化电平低于?25 dB；在宽频带内波束宽度保持相对恒定，且天线E面和H面辐射方向图的?10 dB波束宽度非常接近. 该新型波纹槽可以在宽频带内使得喇叭的辐射方向图更为对称，是改善波纹喇叭性能的新思路.