A Novel Compact Ultrawideband Antenna

In this paper, novel compact ultrawideband (UWB) antennas are proposed and successfully demonstrated within the bandwidth with the ratio of the maximum and minimum frequency to be more than 30. The results from electromagnetics (EM) simulation and measurement show good agreement. From the EM simulation results, the electromagnetic wave could be radiated to the free space through the antenna only if the antenna impedance were matched to one of its feed systems within the bandwidth. The developed antenna with a small size of 17 $times$ 17 $times $ 12 mm$^{3}$ shows voltage standing wave ratio (VSWR) of less than 2.5 : 1 from 3 to 100 GHz for the simulated data, and less than 2 : 1 from 3 to 50 GHz for the measured data. The gain of the developed antenna is more than 2 dBi from 3.1 to 10.6 GHz in the application of high-speed wireless digital communication system.      

一种新型全向高增益印刷天线的设计

设计了一种新型全向高增益印刷天线。该天线采用平衡微带线作馈线．以印刷振子作为辐射单元,末端采用匹配电路对其输入阻抗进行匹配。用商用软件AnsoftHFSS对天线的特性进行了仿真计算。比较表明,测试结果优于仿真结果。该天线工作在SCDMA频段（1785～1805MHz）,其H面不圆度小于1dB,中心频率下增益大于12dB,满足了设计要求。     

新型小型化GPS天线设计

设计了一种用于通信、导航、定位等领域的小型化GPS微带天线.采用了椭圆贴片辐射单元及接地板开槽技术,通过接地板开槽引入微扰,在实现圆极化的同时,减小了天线尺寸,实现了小型化:比同频率下传统圆极化微带天线尺寸减小32%,比同结构矩形贴片增益高35%,且频带宽度和轴比带宽都有所提高.     

A Broadband Dual Circularly Polarized Compact Printed Monopole Antenna

Wireless Personal Communications - Now-a-days the most common pretentious disease is the lung cancer, which has become more prevalent in the world that primarily infects the pulmonary nodules of...     

一种用于无线局域网的双频带印刷偶极子天线

介绍了一种运用于无线局域网的小型化印刷偶极子天线,它采用对偶极子两个臂开槽结构,使其获得双频带和小型化的特性。采用基于耦合馈电的巴伦馈电方式,使天线具有宽带匹配、结构简单、制作方便、易于集成到无线通信设备中的优点。仿真结果表明,在2.4 GHz和5.8 GHz两个频带的带宽分别为590 MHz(2.13~2.72 GHz约24.33%)和700 MHz(5.24~5.94 GHz约12.52%),而且方向图比较理想。该天线的主要优点是结构简单、体积小、低剖面、成本低、易共形,能够满足WLAN的需要。     

一种新型交叉馈电宽带印制天线

设计了一种新型交叉馈电宽带印制天线,该天线对存在耦合的宽偶极子进行电容加载,构成宽频带容性辐射单元,使用平行宽边耦合双线对两个辐射单元进行交叉馈电,实现阻抗匹配调节和提高增益的作用。通过理论分析和HFSS软件仿真计算表明:该天线能够在厚度1mm、εr=2.6的介质板上实现53%的阻抗带宽(VSWR<2.0),并且频段内方向图主瓣不分裂,增益可达4.8dB i,相位中心不随工作频率变化而移动。该天线易于设计和加工,参数易于调整,有较强的实用性。     

一种应用于WLAN的新型多频印制天线

基于微带天线设计思路和方法,设计了一种新型小型化应用于2.4 GHz/5.2 GHz/5.8 GHz多频段无限局域网(WLAN)的微带印制天线并进行了软件仿真,该天线在要求阻抗带宽内有很好的辐射特性,仿真结果验证了文中研究工作的合理性和可行性.     

一种新型小型化差分微带贴片天线

基于天线小型化的考虑,设计了一款适用于WLAN802.11b(2.4~2.48 GHz)系统的差分小型化微带天线。该天线采用差分馈电方式,可以和差分芯片无缝连接。采用在贴片切槽方式来实现小型化,相对于传统差分微带天线,设计出的小型化差分微带天线尺寸缩小了33%左右。利用仿真软件HFSS对设计的差分小型化微带天线进行了仿真分析。数值分析结果表明:天线谐振频率约为2.45 GHz,天线增益约为7.15 d B,回波损耗约为-16.6 d B。     

一种适用于WLAN 的新型小型化双极化天线

设计了一种可工作于WLAN 2.4GHz频段的小型化双极化天线.该天线采用双层对称结构介质板,把辐射贴片四边分别切割成凸字形形状,实现了天线小型化和有效展宽天线带宽.同时在接地板开4个对称的十字形缝隙,进一步拓宽天线带宽和明显减小天线的整体尺寸并提高了天线辐射性能.由此设计制作的天线实验结果为:小于-10dB回波损耗的频段为2.37 ～ 2.59GHz,相对阻抗带宽达9.1％,端口隔离度达到了33dB,增益最大值约3.63 dBi,表明该微带天线具有宽频带和良好的辐射性能.此外,该天线结构简单紧凑,易于加工制作和集成,适合应用于移动终端.     

A Novel Dual-Band Printed Diversity Antenna for Mobile Terminals

A novel dual-band printed diversity antenna is proposed and studied. The antenna, which consists of two back-to- back monopoles with symmetric configuration, is printed on a printed circuit board. The effects of some important parameters of the proposed antenna are deeply studied and the design methodology is given. A prototype of the proposed antenna operating at UMTS (1920-2170 MHz) and 2.4-GHz WLAN (2400-2484 MHz) bands is provided to demonstrate the usability of the methodology in dual-band diversity antenna for mobile terminals. In the above two bands, the isolations of the prototype are larger than 13 dB and 16 dB, respectively. The measured radiation patterns of the two monopoles in general cover complementary space regions. The diversity performance is also evaluated by calculating the envelope correlation coefficient, the mean effective gains of the antenna elements and the diversity gain. It is proved that the proposed antenna can provide spatial and pattern diversity to combat multipath fading.     

一种新式小型多频段终端天线

在对终端天线进行研究的基础上,设计了一种新颖的小型单馈电点平面倒F天线。该天线可工作在GPS（1575.42MHz）、DCS（1710～1880MHz）、PCS（1850～1990MHz）、UMTS（1920～2170MHz）以及WLAN（2400～2480MHz）等五个主要的无线通信频段。根据仿真设计结果加工了实物模型,进行了天线性能测量,并对天线安装在载体上的实际性能进行了测量,给出了测试方向图。实验结果表明,该天线完全适用于多频段无线通信系统。     

新型低剖面辐射单元及小型双极化天线

基站天线大都利用对称振子辐射单元组成,而常规对称振子的高度通常为工作中心频率的1/4 波长 左右。提出一种新型的低剖面对称振子辐射单元,高度只为工作中心频率的1/8 波长,在1. 71 ~2. 17GHz 的宽频带 范围内,具有良好的阻抗特性和辐射特性。采用电磁仿真软件ANSOFT HFSS 建模仿真,实现了一款小型双极化天 线,其体积达到同频率常规天线的一半,而且实测结果与仿真数据相吻合。该天线性能稳定,造价成本低,实用价值 很大。     

一种新型具有双陷波特性的超宽带天线设计

本文提出了一种新型紧凑的具有双陷波特性的印刷超宽带天线。天线采用微带传输线馈电,并通过圆形与矩形 的混合结构辐射单元和带有矩形开槽结构的地板来实现天线的超宽带特性,工作带宽覆盖UWB 频率范围。通过地板上 两个对称的J 形开槽和微带馈线两侧对称添加的线型结构单元来实现双陷波特性,两个陷波频段刚好覆盖了3.5GHz 的 WIMAX 频段标准和5.2/5.8GHz 的WLAN 频段标准。同时,该天线在工作频带范围内具有良好的辐射特性,符合超宽带 通信的使用标准。     

一种新型低成本的圆极化GPS微带天线

目前GPS接收机中所使用的微带天线为了缩小尺寸常常采用高介电常数的微波材料进行设计,但高介电常数的微波材料会引起表面波并且成本会很高。利用常用的FR4PCB板材并在微带贴片上采用开槽的方式,以增加电流路径降低谐振频率的方法来缩小天线的尺寸,从而得到低成本、小尺寸的圆极化GPS天线。利用全波电磁仿真环境HFSS进行3D建模与电磁仿真分析,得到天线的各项性能参数,仿真结果满足GPS接收机所需天线的性能要求。     

一种新型三频段内置天线的设计

随着移动终端的小型、多样化的发展,如何设计一个多频段、小尺寸、低剖面的内置天线成为移动终端天线设计的难点。以双分支平面倒F型天线为基础,通过增加寄生的短路分支,利用不同的路径分支激发各自频段的方式,实现在VSWR<3.0内涵盖GSM900、DCS、PCS三个操作频段的一款新颖的内置天线。天线由2个短路柱、1个馈电柱和在天线辐射体上切割裂缝与缝隙构成,并利用仿真环境HFSS进行3D建模与电磁仿真,仿真结果满足三频段天线的性能要求。     

一种制作可变光衰减片的新方法

介绍了一种制作可变光衰减器用衰减片的新方法,即采用曲线型沉积孔挡板,结合基片旋转,在玻璃基底上获得厚度线性变化的溅射金属膜层,形成可变光衰减器。     

A Novel Numerical Model for Simulating Three Dimensional MIMO Channels With Complex Antenna Arrays

We develop a novel three-dimensional (3D) numerical model for rigorously simulating mutual coupling effects on the channel capacity of the multiple input multiple output (MIMO) systems. In this model, the efficient integral equation method mutlilevel Green's function interpolation method (MLGFIM) is for the first time employed to calculate the input admittances and radiation patterns of the transmit and receive antennas of MIMOs. Comparing with the Method of Moments whose complexity is $O(N^{2})$ , MLGFIM has an efficiency of $O(Nlog N)$ and is suitable for efficiently solving antenna arrays problems. To accurately model the EM wave propagation, we 1) use the ray tracing method to obtain the multi-paths and 2) rigorously obtain the dyadic path loss factor model from which a novel stochastic path loss model that is flexible for both the environments with PEC walls and that with infinite thick lossless dielectric walls is devised. Using the proposed model, we successfully analyze mutual coupling effects on the 3D correlation of a 2-by-2 monopole array and the indoor channel capacity of a 20-by-20 planar array and a 20-by-20 icosahedron array. The numerical examples in this paper demonstrate the efficiency of our model for simulating the MIMO system with complex radiators.      

A Complementary Antenna Array Used in Radio Frequency Identification

1IntroductionRadioFrequencyidentification(RFID)hasbeendevelopedrapidlysince1990.ComparedtOmagneticcardoriCcardwithitSnon-contactoperation,itiscalledanewgenerationofidentificationtechniqueforusingradiofrequencytorealizehi-directionalcommunicationsll~3].ItoftenusesanantennaarrayforlongerworkingdistanceandmorestabilityinRFIDsystems.Formutualcomplementinradiationpatterns,tWoformsofgateshapedantennaarrayareintroducedhere.Experimentsshowthatitagreeswiththetheoreticalanalysis.2NearFieldAnalysi…     

A Compact Broadband H-Slot and Horizontal H-Slot Patch Antenna for Circular Polarization

This paper presents the design of compact broadband H-slot and horizontal H-slot microstrip patch antenna with a single feed. The antenna is also used for circular polarization application with a single narrowband frequency. The performance of single feed notched and truncated corner circularly polarized microstrip antennas with the same substrate thickness for H-slot and horizontal H-slot is studied. The simulated results such as return loss S₁₁, axial ratio AR, radiation pattern (E_left and E_right), and gain are presented in this paper for different shapes of patch antenna.     

一种新型海事卫星天线分析与设计

针对海上石油钻井平台地理环境对通信天线的特殊要求,提出了一种宽频带圆极化平面天线,该天线适用于新一代Ka频段海事卫星终端。天线采用基于微扰法的矩形贴片作为辐射单元,对微扰槽位置等参数利用矩量法进行了优化,并采用耦合馈电方式来提高天线的圆极化带宽。仿真结果表明,该天线具有良好的阻抗及轴比带宽,分析了天线的辐射特性,并对比了不同的仿真结果。该天线具有结构紧凑,馈电简单、圆极化特性好、易于制作等优点。