使用混合单元的微带反射阵列天线

混合使用了两种形式微带贴片单元在Ku波段实现了反射阵列天线,一种形式为不同大小贴片,另外一种形式为带不同长度延迟线的贴片。通过使用两种形式的贴片,优化了贴片单元的反射方向图,使其最大反射方向始终朝向阵列最大辐射方向,从而保证了阵列的效率。仿真与实测结果表明,所设计的口径约为13.5波长的反射阵列天线在5.5%的带宽内,实现了效率大于48%的设计。     

宽带缝隙堆叠贴片微带反射阵天线的研究

微带反射阵天线具有易折叠、易携带等特点,结合缝隙堆叠贴片（ASP）微带单元频带较宽的优势,能进一步展宽缝隙耦合反射阵的带宽。通过求解相位计算公式,得到反射阵表面相位分布。给出了ASP微带天线的设计参数、S参数曲线及对应ASP单元的反射相位曲线,用所设计单元组成225元反射阵模型,结果显示该模型中心频率最大增益为26.03dBi,1.5dB增益带宽为33.3%,在整个带宽内具有良好的工作性能。     

微带反射阵天线的分析与设计

介绍了微带反射阵天线的基本原理,分析了天线设计中阵元单元尺寸和间隔的计算、相位延迟线的选择、基片厚度的选取、误差分析、仿真验证等,根据分析结果提出了低副瓣微带反射阵天线的设计方法。实例测试结果表明,反射阵天线的总体性能接近抛物面天线的性能,易于折叠、携带方便。     

宽带低副瓣微带反射阵列天线

为了实现便携式雷达设备的轻小型化,系统采用微带反射阵列天线替代传统的抛物反射面天线.该天线设计的难点是如何实现雷达工作频带内的天线低副瓣特性.采用微带延迟线的移相方案,并提出微带贴片与延迟线满足线性相移关系的匹配原则,实现了反射阵列天线的宽带低副瓣特性.实测结果表明,在X频段3.2%的带宽内,天线副瓣电平低于-25 dB,并且天线效率不低于50%.     

Novel Broadband Reflectarray Antenna with Two-Type Elements for Millimeter-Wave Application

A novel broadband millimeter-wave microstrip reflectarray antenna with square-annular patches and combined patches has been presented, aiming to solve the problem of how to obtain a full 360° range of phase shifts for single-layer. The choice of these two-type elements can make the phase shift smoother and increased up to 360°, leading to broader bandwidth. Based on this technique, a single-layer microstrip reflectarray antenna operating at 94 GHz has been designed. The computed results demonstrate the agreement of the main beam steering with the design requirement, and a 1-dB gain bandwidth close to 10% is obtained. The simulation results verify the feasibility of this design.     

Novel Broadband Reflectarray Antenna with Windmill-Shaped Elements for Millimeter-Wave Application

A novel broadband millimeter-wave reflectarray antenna composed of windmill-shaped elements of variable lengths is proposed. Compared to the conventional single-layer reflectarray elements, the windmill-shaped elements can realize much larger phase variation range (over 600°), leading to broader bandwidth. Using this technique, a 15°-beam-steering reflectarray operating at 30 GHz is designed. The computed results demonstrate the agreement of the main beam steering with the design requirement, and a 1-dB gain bandwidth close to 20% is obtained. The validity of the obtained results is verified by comparing the ones generated by Ansoft High Frequency Structure Simulator (HFSS) with those produced by Ansoft Designer. The antenna is useful for millimeter-wave applications.     

基于毫米波微带天线设计的射频电路实验

本文设计了一个新的射频电路设计性实验项目——可用于无人机高度测量的毫米波雷达微带天线的设计与实现。该实验项目通过让学生完成该天线的自主设计、仿真、优化、制作和测试的过程,引导学生来深入体会实际射频工程中的实际流程和方法,从而提高其学习兴趣,进而进一步培养其工程素质、实践能力和创新精神。     

一种渐变槽线作馈源的新型微带反射阵

提出了利用渐变槽线天线物理截面小的特点与变极化技术相结合的方法来改善微带反射阵馈源的遮挡效应,并设计了用于变极化微带反射阵馈源的渐变槽线天线及含37单元的微带反射阵。鉴于这些特点,该类天线在雷达、移动通信等领域具有潜在工程应用。文中给出了部分的理论分析和实例佐证。     

双频宽带大型微带反射阵天线设计

微带反射阵天线在性能上最主要的缺陷就是窄带,一般情况下其带宽小于5%,对电大口径短焦距馈电时更窄。本文设计并制作出一种由L波段和C波段两个反射面天线组成的6m×2m薄膜双频微带反射阵天线,两个频段的天线共用一层膜面。对该天线的电性能进行了测试,测试结果表明:该天线两个频段的相对带宽均大于10%(副瓣电平≤-18dB)。该天线具有折叠、可展开的结构特征,可以在卫星或航天器上广泛应用。     

新型单层双频双极化微带反射阵天线的设计

该文提出一种新型的具有多谐振结构的单层微带反射阵单元,是由6个振子以一定的间隔平行放置组合而成,该单元具有良好的线极化特性。采用高频电磁仿真软件HFSS对单元的各个参数进行优化分析,使得单元的反射相位曲线在两个频段内均具有良好的线性度。根据此单元设计了一个工作在X/Ku波段的偏馈双频双极化微带反射阵天线,在两个频段内采用同一个角锥喇叭天线作为其馈源。将此反射阵天线进行加工并测试,测试结果表明,在X波段中心频率10 GHz和Ku波段中心频率13.58 GHz处,天线均具有良好的辐射性能。实测和仿真结果吻合较好,证明了该反射阵天线具有良好的双频辐射性能。该文的设计对于微带反射阵列天线实现双频双极化性能具有重要的参考价值。     

新型毫米波宽带圆极化微带天线阵列设计*

提出了一种基于H形缝隙耦合的毫米波方形切角圆极化微带天线单元,对影响其轴比特性的各参数进行了分析,并采用这种新型天线单元设计了4×4毫米波宽带圆极化微带天线阵列.仿真结果表明,该天线阵列阻抗带宽(S11＜-10dB)和轴比带宽(AR＜3dB)分别达到了25.9％(32.2 ～41.8GHz)和20.1％(32.6～ 39.9GHz),与传统圆极化微带天线阵列相比,分别提高9.7％和14.7％,天线阵列最大增益为19dB,在整个轴比带宽内,增益均大于15 dB,副瓣电平及交叉极化电平均较低.     

一种自适应的毫米波多波束天线

本文设计了一种自适应的毫米波多波束天线.采用一种新颖的馈电方式来产生低副瓣、高增益、高邻近波束重叠的窄波束.并且采用数字波束形成技术来产生多波束.仿真和计算结果表明,这个天线的波束波瓣宽度可以达到1°,并且副瓣电平低于-25dB.采用自适应技术后,可以得到小于-30dB的理想零陷.     

Design of a Compact Millimeter-Wave Microstrip Antenna with Wide Bandwidth and Broad Beamwidth

Design of a novel compact millimeter-wave microstrip antenna with wide bandwidth and broad beamwidth is presented. In the structure, multiple layers and a parasitic element as well as a coupling aperture are used to achieve wideband, while a conducting cylinder and the coupling aperture are used to obtain broad beamwidth. Finally, phased array with eight present elements has been designed as an example. Compared to traditional microstrip antennas and arrays, present antenna and array are of smaller dimension and broader beamwidth as well as wider bandwidth.     

十字形贴片双模微带带通滤波器

基于传统的贴片型双模微带带通滤波器,提出了一种结构新颖、简单的滤波器.该结构是在十字形贴片谐振器上刻蚀正交的T形槽通过中心处的方开槽相连.对该结构进行优化,优化后的滤波器能在通带两侧都产生衰减极点,提高阻带的抑制能力,同时保证滤波器的小型化.该滤波器仿真结果表明通带中心频率为2.75 GHz,最大回波损耗优于-32dB,通带内最小插入损耗为0.60dB,3dB带宽达到59.8％,实测和仿真结果相一致.     

一种微带反射阵列天线单元带宽拓展方法

在微带反射阵列天线设计中,采用大小不同、结构相似的多个空心单元于同一层面上嵌套形成组合单元,可以拓展单元带宽.通过几种单元实例计算对比和实验阵面性能的仿真分析,结果表明采用此组合单元可有效拓展阵中单元及微带反射阵列天线系统的工作带宽.应用此组合单元法步骤简单,具有一定的通用性,可为各种反射阵列天线设计和工程实践参考.     

A Single-Layer Ultrawideband Microstrip Antenna

A single-layer microstrip antenna for ultrawideband (UWB) applications, in which an array of rectangular microstrip patches was arranged in the log-periodic way and proximity-coupled to the microstrip feeding line, is presented. In order to reduce the number of microstrip patches in the UWB log-periodic arrays, a large scale factor ${rm k}=1.1$ was firstly reported and proved to be highly effective. Furthermore, instead of using an absorbing terminal loading, a novel loss-free compensating stub was proposed. Detailed parameters study was also presented for better understanding of the proposed antennas. The impedance bandwidth (measured ${rm VSWR}≪2.5$ ) of an example antenna with only 11 elements is from 2.26–6.85 GHz with a ratio of about 3.03:1. Both numerical and experimental results show that the proposed antenna has stable directional radiation patterns, very low-profile and low fabrication cost, which are suitable for various broadband applications.      

一种宽带缝隙耦合微带天线

采用"hour glass"形状缝隙设计了一种新型宽带缝隙耦合微带天线,分析了缝隙参数对天线输入阻抗的影响.该天线使用了多层聚四氟乙烯介质,不仅对贴片单元进行了保护,而且增加了天线的机械强度.同时,由于其结构简单,因此便于阵列集成.研究结果表明,该天线相对带宽超过30%(VSWR<2.0),E面和H面交叉极化分别低于-40 dB和-35 dB.     

一种新型超宽带微带天线

目前超宽带无线通信成为研究的热点,同时对天线的研究提出新的挑战.提出了一种小型超宽叉形微带天线结构,首次采用对地板做开一个半圆形缝隙处理,提高了天线辐射性能,而对其他参数影响不大.通过数值模拟,该天线主抗带宽为3.5～14 GHz,基本覆盖了FCC建议的频段.其在XZ面具有良好的全向,在YZ平面辐射图具有很好的稳定性.此天线结构具有良好的辐射特性,基本满足了超宽带通信对天线的要求.     

Dual-Mode Microstrip Open-Loop Resonators and Filters

A miniature dual-mode microstrip open-loop resonator is proposed. Distinct characteristics of this new type of dual-mode resonator are investigated using full-wave electromagnetic simulations. It is shown that the two operating modes, i.e., the even and odd modes, within a single dual-mode resonator of this type do not couple. It is also found that there is a finite-frequency transmission zero inherently associated with the even mode. Two two-pole filters using this type of dual-mode resonator are demonstrated with opposite asymmetric responses, which result from different locations of the transmission zero. Higher order filters of this type are also investigated. Both simulated and measured results are presented.