100kHz～50MHz宽带环形天线

本文介绍的宽带环形天线,接收频率范围为100kHz～50MHz而无需开关转换。适用于长波、中波到短波甚至10米波的接收。该电路设计精巧,装配简单,效果良好。理想的天线实际上是不存在的。任何一个天线的设计,最终无不折衷于各种各样的矛盾。对于频率在50MHz以下的天线,设计时天线的尺寸就是一个很大的问题。对于宽带接收天线大多数是采用分段调整的力法,然而这不是我们所希望的。宽带天线除了要求高灵敏度和低噪声外,还要求对噪声和大信号具有良好的抑制能力以及具有尽可能平坦的频率响应。这样的天线在充满各种干扰的大城市中也能使用。针对上述要     

Sinuous天线

介绍了一种新型的宽频带双极化天线，该天线具有平面、宽频带、全极化和单口径的特点。该天线在功能特性上类似于对数周期天线，可将它看作为一种平面对数周期天数。     

一种改进的手机PIFA设计

介绍了PIFA的发展历程及原理,分析了其设计结构。基于HFSS,对典型PIFA进行建模仿真,仿真结果发现天线的高频带宽较窄,进而对相关参数进行了优化。提出了一种在高频段增加寄生分支的方法,改进了天线在高频段的回波损耗,使得天线在高频段得以进行扩展,同时也能够在低频段更好地进行匹配。     

一种机载通信天线设计与实现

针对某型飞机研制要求,设计了一种基于四分之一波长平面单极子的机载通信天线,重点阐述了天线辐射体设计、匹配网络设计和闪电防护设计等内容。通过地面测试和装机试飞验证,表明了该机载通信天线性能良好,完全能够取代现役英国37R-2型通信天线。     

我设计的一款简易高效电视接收天线

纵观当今市售的地面天线,尽管门类繁多,品种各一,但都未能突破日本八木天线的传统结构特点,都少不了引向器和反射器,因而其固有的缺陷仍有所遗留。本人研制的这种天线,从根本上打破了日本八木天线的固有局限,免去了引向器和反射器,也不受天线材料的限制,从而实现了简易、高效、长寿命、宽频带、多用途的目标。有兴趣的朋友不妨一试。     

一种基于分形结构的超宽带天线研究

基于微带天线和分形天线的基本理论,采用正方形和圆形交替的方法设计了用于超宽带（UWB）通信的分形天线。利用电磁仿真软件CST软件对所设计的天线进行仿真、优化,并分析了影响天线阻抗特性和辐射特性的关键参数。从仿真实验结果可以看出,所设计的天线有较好的全向辐射特性和宽的阻抗带宽,能够满足超宽带通信需求。     

高精度,高集成度智能天线控制器

介绍一种高精度、高集成度智能天线控制器。该控制器能实时显示天线的方位角和俯仰角，分辨率为０．０１°，按选择键也可显示无线的极化角；能方便地显示和修改系统参数和工作参数，这些参数均有掉电保护；选择相应的功能键，可完成微动、定位、搜索和跟踪等功能。测试结果表明：该控制器具有检测精度高、控制功能多、使用方便的特点。     

PCB天线的分析及应用设计

本文首先分析常见的几种PCB天线设计的优缺点,然后结合一款设备发射频率为430MHz,尺寸非常紧凑(28.1mm×5.5mm)的产品,分别按照几种常用的PCB设计进行了讨论,最后重点研究了PCB螺旋天线的设计方案。实验测得PCB螺旋天线的信号强度和辐射距离完全符合设计要求,各项功能运行良好。     

基于一种新形核函数高斯过程的双频微带天线设计

针对采用高斯过程进行建模时,不同核函数形式有着不同学习效果的问题。提出了一种自定义的平方指数形式的核函数,并基于多项式函数拟合对这种新形的核函数进行了数值仿真。仿真结果表明,该核函数不但可以提高模型的精确度和有效性,而且可以提高模型的学习能力和泛化能力。最后,将基于该核函数的高斯过程建模方法用于矩形双频微带天线优化设计和WLAN双频单极子天线优化设计,进一步证明了这种方法是可行的和有效的。     

空间碎片对充气天线性能的影响

空间碎片对航天器安全造成很大威胁,为了分析宇宙环境中空间碎片对充气天线物理性能的影响,采用LS-DYNA软件定量给出空间碎片对充气天线外形的影响,进而分析了天线形面变形对电性能的降低和破坏,结果显示受较大尺寸空间碎片冲击时,充气天线会被穿透,必须补充一定的气体才能保持充气天线的形状和压力。     

A compact double‐layer wideband circularly polarized microstrip antenna with parasitic elements

In this article, a new broadband circularly polarized (CP) microstrip patch antenna (MPA) with a sequential phase (SP) square‐loop feeding structure is proposed. The presented antenna is composed of a square‐loop feeding structure, four L‐shaped parasitic patches with L‐shaped slots, four parasitic square patches, and a corner‐truncated square patch. At first, a SP square‐loop is designed as a feeding structure. Then, four L‐shaped parasitic patches with L‐shaped slots are utilized to generate one CP mode by a capacitive coupled way. At last, four parasitic square patches and a corner‐truncated square patch are together placed above the SP feeding structure to broaden the circularly polarized bandwidth (CPBW). The presented antenna has a wide 3‐dB axial ratio bandwidth (ARBW) of 16.7% (5.4 GHz, 4.95‐5.85 GHz), and a wide 10‐dB return loss bandwidth of 25.5% (5.5 GHz, 4.8‐6.2 GHz). The proposed antenna features compact structure and broad 3‐AR bandwidth which could completely cover the WLAN (5.725‐5.85GHz) band. Therefore, the proposed antenna is suitable for circular polarization applications in C band.     

星载环境充气可展开天线硬化技术研究

在轨空间充气天线硬化对于天线保形、抵御空间碎片影响具有重要意义。对充气可展开天线硬化材料、硬化技术等进行了分析和设计,并对铝箔/塑料薄膜材料进行了详细的硬化力学分析,计算结果表明铝箔Mylar硬化技术是充气可展开抛物面天线硬化的有效手段。     

基于STM32的射电望远镜跟踪系统设计

为了满足天文爱好者的对射电天文学的探索,对于大型的射电望远镜天线,其指向精度要求高,观测的过程中需要做各种实时修正,造价昂贵,并不适合用于科普,因此设计了一种基于STM32微处理器的双轴射电望远镜控制系统。系统通过两台直流电机控制抛物面天线对太阳的运动轨迹进行跟踪并实时采集射电望远镜接收机电压,并将采集的数据利用TCP传输方式快速送至PC机用户监控软件进行显示和存储。该系统实现了时间分辨率为1ms的太阳射电数据采集与存储,提高了系统捕获持续时间很短的太阳爆发能力,为科普爱好者研究、分析太阳活动提供了数据支撑。     

WJ-100智能卫星电视天线姿态控制器

WJ-100智能卫星电视天线姿态控制器能够对卫星地面站天线进行全自动控制或遥控,它采用微机控制技术,全集成模块化电视以及PL/M高级语言编程。功能齐全,使用维修方便,运行安全可靠,抗干扰能力强,具有较高的推广应用价值。     

Radiated cross‐polar levels and mutual coupling in patch radiators

This article presents the relation between the cross‐polar signal radiated by a dual feed patch antenna and the mutual coupling existing between the antenna feeds. The theoretical analysis is based on the S‐parameters of the antenna element, providing a clear understanding of the physical relation between cross‐polar level and coupling. Analytical expressions are given for the radiation pattern computation, including the cross‐polar level and the effect of higher order modes on the pattern. Finally, the results of the study are illustrated with measured patterns. © 2000 John Wiley & Sons, Inc. Int J RF and Microwave CAE 10: 342–352, 2000.     

Design of a 16‐beam pattern‐reconfigurable antenna for vehicular environment

This article presents the design of a multipattern antenna with pattern switching for vehicular communications. The proposed antenna has four triangular patches integrated onto a split square ring (SR) resonator to operate at two distinct frequencies, viz. 2.4 and 3.5 GHz. The proposed antenna is designed with a view to enhancing the link reliability of Wireless Local Area Network (WLAN), WiMax, and vehicle to vehicle communication frequencies. Each triangular patch is separately excited using a microstrip line feed to enable beam steering. The ground plane of the antenna is embedded with two SR slots to improve the bandwidth and radiation performance. Further gain enhancement is achieved by loading the antenna with a plane reflector located at a distance of 20 mm from the antenna's ground surface. In reality, this reflector is realized using the vehicle's roof which provides gain enhancement up to 5.2 dBi at 2.4 GHz and 4 dBi at 3.5 GHz. By exciting single to multiple ports sequentially 16 different radiation patterns are obtained, which provides high‐gain omnidirectional coverage. The prototype antenna is fabricated and the simulation results are verified using experimental measurements. From the results, it is evident that the proposed antenna is suitable for vehicular communication applications.     

Optically transparent broadband water antenna

In this article, we investigate an optically transparent broadband water antenna, which is composed of a cross‐shaped slot feeding structure and a thin layer of water supported by a transparent dielectric slab. This water antenna can be analyzed as an embedded stacked dielectric resonator (DR) antenna (DRA) mounted on a ground plane. Two distinct resonator modes—namely, DRA mode and dielectric‐loaded slot (DLS) mode—are excited to achieve a good impendence matching over a very wide frequency range. A prototype antenna is designed, fabricated, and measured. Measured results demonstrate that the designed water antenna exhibits a broad impedance bandwidth of about 37% from 1.07 to 1.56 GHz with antenna efficiency better than 65% and broadside radiation characteristics with low cross‐polarizations.     

Multiband antenna for mobile terminals

In this paper, a multiband antenna composed of a tri‐mode monopole, an open‐slot etched on the ground, and a parasitic strip is proposed for mobile terminals. The tri‐mode monopole excites three modes including 0.25 λ, 0.25 λ, and 0.75 λ modes at 0.9, 1.85, and 2.4 GHz respectively, and can cover the desired frequency band 1.7 to 2.7 GHz. The open slot etched on the ground can obtain better impedance matching at 0.9 GHz to cover 0.82 to 0.96 GHz. To further broaden the bandwidth of the low frequency, a parasitic open‐ended strip is used to introduce a new resonance to extend the lower frequency band to 0.69 GHz. The proposed antenna is simulated, fabricated and measured. The impedance bandwidths with S₁₁ better than ?6 dB are 270 MHz (0.69‐0.96 GHz) and 1.06 GHz (1.7‐2.76 GHz). The consistency between the measured and simulated results indicates that the proposed antenna is available for mobile phone applications.