Design of an Internal Antenna with Near‐Omnidirectional H‐Plane Radiation Pattern over Ultra‐wide Bandwidth

In this paper, an ultra‐wideband internal antenna for use in mobile applications is proposed. The proposed antenna has symmetrical bi‐arm structures printed on the top and bottom of the substrate, and it occupies a compact area of 10 mm × 10 mm × 1 mm. The designed antenna has an impedance bandwidth from 3 GHz to 12 GHz and near omnidirectional radiation patterns over the frequency band of interest. The group delay between two antennas fabricated using the proposed design is less than 0.8 ns, and the maximum gain variation is about 3.16 dB.     

一种新型的超宽频天线的设计

提出了一种微带馈电的新型超宽频的天线,该天线印刷在覆铜介质基板上,介质基板尺寸为30.0 mm×35.0 mm×1.6 mm,材料是介电常数为4.4的FR4介质,利用仿真软件HFSS对天线参数进行仿真和优化.通过在微带面上开缝,可实现天线频带宽度(回波损耗S11＜-10 dB)2.6～11.5 GHz,相对带宽达126％.结果表明,该设计天线不仅满足超宽带要求,且结构简单,体积小,适合在超宽带天线(UWB)通信中应用.     

On the Degradation of a UWB System Due to a Realistic TX‐RX Antenna System

The ultra‐wideband (UWB) signal radiation process in an antenna is different from that of a narrowband signal. In this paper, we study the degradation of the desired signal component according to the antenna structure and location of a receiver in a bipolar time‐hopping UWB system. And we propose a receiver structure with an adaptive template waveform generator to compensate for the degradation caused by a realistic TX‐RX antenna system.     

新型宽带螺旋天线的小型化设计

基于人工介质基底的螺旋天线小型化设计,利用螺旋天线的固有属性——有效辐射区和异形腔的设计思路,设计了人工介质基底,通过控制人工电介质材料中圆盘的半径来控制介质基底相应位置的有效介电常数,在保持相对带宽和较高增益的前提下,很大程度上降低了天线的厚度,从而实现了螺旋天线的低剖面小型化设计,使得天线利于与载体共形,这是一种螺旋天线小型化设计的全新思路。     

Chirp‐Based Cognitive Ultra‐wideband Radio

In this letter, we propose a cognitive ultra‐wideband radio scheme which is based on a modified chirp waveform. Therefore, it requires only time domain processing in the cognitive radio systems and reduces system complexity and power consumption.     

一种改进的小型超宽带天线

为了有效地对超宽带天线进行小型化,通过对平面椭圆单极子超宽带天线进行切半和切边处理,设计了尺寸为10mm×17mm的小型超宽带天线。为了改善因对天线进行切半而恶化的全向辐射特性,在小型超宽带天线的辐射体中引入了缝隙结构。仿真结果表明:改进的小型超宽带天线在整个超宽带频带内具有良好的阻抗匹配和全向辐射特性。该天线的测量结果与仿真结果基本吻合。     

宽带平面螺旋天线的研究与设计

平面螺旋宽带天线具有频带较宽、体积较小、圆极化性能较好等特点,应用范围很广。但是这种天线增益较低,馈电匹配较难实现,尤其是前者,使得其性能大打折扣。通过研究影响平面螺旋宽带天线增益和馈电匹配的主要因素,设计了2~7GHz范围内的宽频带平面螺旋天线。理论分析和仿真实验结果表明,对改善平面螺旋宽带天线的性能有一定的工程参考价值。     

一种超宽带高增益的透镜喇叭天线的设计

该文提出了一种适用于微波通讯系统的超宽带(UWB)高增益透镜喇叭天线。该天线由一个E面喇叭天线,一个球面介质透镜和双楔形金属脊构成,并由同轴线馈电及采用HFSS软件仿真。仿真结果表明,双楔形金属脊可有效增加喇叭天线的带宽,有效频率带宽达到2～12 GHz。当仅使用双金属脊来改善喇叭天线的性能时,喇叭天线的增益会下降。文中使用一种球面介质透镜来补偿双金属脊对喇叭天线增益的负面影响。仿真结果表明,该透镜可有效提高喇叭天线在工作频带内的增益。采用透镜和金属脊结构后,该喇叭天线拥有超宽带,高增益和较强的定向辐射性能,可以应用于各类通信系统中。     

一种用于隧道覆盖的超宽带单极子天线

通过分析目前隧道或地铁工程中经常使用的泄漏电缆覆盖成本较高的不足,提出了一种新的设计方案——双向天线覆盖,并且根据平面单极子的辐射特性,采用电磁仿真软件Ansoft HFSS建模仿真,设计并实现了一款在155～1057 GHz频带内具有良好阻抗特性的环形椭圆平面单极子天线,其相对带宽接近150%,水平面辐射方向图是沿着隧道双向分布的,而且实测结果与仿真数据相吻合。该天线结构简单,容易实现,采用壁挂形式,安装方式简单可靠,造价成本低。     

宽带平面直角双频单极天线

对于超宽带系统,需要具备可工作频率为3.1~10.6GHz的宽带天线。本文介绍了四种宽带平面单极天线,分别为圆形平面单极天线、平面直角单极天线、平面双频单极天线和平面直角双频单极天线。其中平面直角单极天线兼具宽频和全向特性,平面双频单极天线和平面直角双频单极天线在两个谐振点都具有宽带特性,平面直角双频单极天线在整个频带内水平面的辐射方向图几乎都可以达到全向。     

Compact Folded Monopole Antenna Excited by a Conductor‐Backed Coplanar Waveguide with Vias

A compact monopole antenna excited by a conductor‐backed coplanar waveguide (CBCPW) is developed for wireless USB dongle applications. The proposed antenna has a compact dimension of 14 mm × 47.4 mm × 3.5 mm, which is suitable for a USB dongle housing. A slotted elliptical patch and a CBCPW with vertical vias are employed to achieve a further size reduction and an improved impedance bandwidth. The measurement result demonstrates that the fabricated antenna resonates from 2.25 GHz to 10.9 GHz, which covers all of the important wireless communication bands, including WiBro (2.3 GHz to 2.4 GHz), Bluetooth (2.4 GHz to 2.484 GHz), WiMAX (2.5 GHz to 2.7 GHz and 3.4 GHz to 3.6 GHz), satellite DMB (2.605 GHz to 2.655 GHz), 802.11b/g/a WLAN (2.4 GHz to 2.485 GHz and 5.15 GHz to 5.825 GHz), and ultra‐wideband (3.1 GHz to 10.6 GHz) services. The radiation characteristics of the proposed antenna when attached to a laptop are tested to investigate the influence of the keypad and the LCD panel of the laptop.     

新型超宽带微带单极子天线的设计

针对目前已有超宽带微带单极子天线带宽较窄及尺寸较大等缺点,该文设计了一款小型化结构新颖的超宽带微带单极子天线,使用HFSS软件对天线的结构尺寸进行了分析.天线尺寸仅为14 mm×25 mm×0.7 mm,采用中间开正六边形槽的圆形辐射贴片、矩形微带线及缺陷地面结构,实现了良好的超宽带特性.最终仿真结果表明,在频率2.0...     

超高频天线宽带小型化技术的新进展

阐述当前超高频天线宽带小型化的几种主要技术,具体介绍了三种新型机栽超高频合成孔径雷达天线的结构和电参数,指出了超高频天线宽带小型化的发展方向。     

新型超宽带单极子天线的设计

研制了一款超宽带印刷单极子天线,通过在接地板上开方形槽,展宽带宽的同时也改善了带内特性.再在金属贴片顶部开扇形槽,进一步在高频段展宽了频带.实测结果显示,改进后的天线- 10 dB阻抗带宽为2.1 ～25.5 GHz,而原不加槽天线的仿真带宽为2～11.4 GHz,带宽展宽了14 GHz.仿真和实测结果显示,天线在2....     

Design of an Ultra‐Wideband Antenna Using a Ring Resonator with a Notch Function

This paper describes an ultra‐wideband (UWB) antenna that uses a ring resonator concept. The proposed antenna can operate in the entire UWB, and the IEEE 802.11a frequency band can be rejected by inserting a notch stub into the ring resonator. The experiment results indicate that the measured impedance bandwidth of the proposed antenna is 17.5 GHz (2.5 GHz to at least 20 GHz). The proposed UWB antenna has omnidirectional radiation patterns with a gain variation of 3 dBi (1 dBi to 4 dBi).     

一种小型化弹载共形天线的设计

精确制导导弹的隐蔽性以及抗干扰特性对弹载天线的带宽提出了更高的要求,而且在安装空间受限的弹载应用场合,弹载天线必须具有较低的剖面高度才能保证导弹的气动外形及飞行性能,因此,性能优越的超宽带天线以及共形天线成为重要的研究方向.文章以圆台形金属弹体为载体,设计了对数周期天线以及小型化改进的对数周期天线共形于圆台金属弹体表面...     

小尺寸多层平面式螺旋天线的仿真设计

本文介绍了一种小尺寸多层平面式螺旋天线,通过近场耦合实现在频率范围10～300MHz之间的短距离数据通信。这种平面式结构采用PCB工艺,通过圆形螺旋绕组,由过孔连通每层线圈,并将不同螺旋圈数、不同层间距、收发天线之间不同距离等对天线特性的影响进行仿真研究。仿真结果表明,随着天线圈数的增加,天线的谐振频率减小,电场减弱,而磁场增强。     

室内蜂窝用曲折臂阿基米德缝隙螺旋天线设计

文中设计了一种用于室内蜂窝通信的正弦波曲折臂阿基米德缝隙螺旋天线。在阿基米德螺旋线中加入正弦波可以在螺旋线半径一定的情况下更好的延长天线臂的电长度,提高天线的小型化程度,并有助于保持传统阿基米德缝隙螺旋天线优良的辐射特性。仿真和测量结果表明:在0.4GHz～2.5GHz的频率范围内,与传统的阿基米德缝隙螺旋天线相比,文中设计天线口径面积减少了62.3%。     

加载介质透镜的超宽带平面螺旋天线设计

针对乳腺癌检测、成像等医疗领域对天线高增益及宽频带的需求,研究设计了一款加载介质透镜的超宽带平面螺旋天线。该天线采用双臂平面阿基米德螺旋天线作为辐射单元,在辐射臂外围间隔一定距离处加载金属圆环以改善驻波性能,并由指数渐变式微带巴伦作为馈电结构。天线顶部加载介质透镜,底部设置金属圆台形反射背板,实现了调整波束形状和提高天线增益的目的。加装圆柱形天线罩后天线高度约为87.53 mm,直径约为46.50 mm。仿真结果显示,天线在3－12 GHz 工作频带内回波损耗小于-10 dB,辐射方向图呈现良好的定向辐射特性,实测结果与仿真结果基本一致。     

Initial Timing Acquisition for Binary Phase‐Shift Keying Direct Sequence Ultra‐wideband Transmission

This paper presents a parallel processing searcher structure for the initial synchronization of a direct sequence ultra‐wideband (DS‐UWB) system, which is suitable for the digital implementation of baseband functionalities with a 1.32 Gsample/s chip rate analog‐to‐digital converter. An initial timing acquisition algorithm and a data demodulation method are also studied. The proposed searcher effectively acquires initial symbol and frame timing during the preamble transmission period. A hardware efficient receiver structure using 24 parallel digital correlators for binary phase‐shift keying DS‐UWB transmission is presented. The proposed correlator structure operating at 55 MHz is shared for correlation operations in a searcher, a channel estimator, and the demodulator of a RAKE receiver. We also present a pseudo‐random noise sequence generated with a primitive polynomial, 1+x²+x⁵, for packet detection, automatic gain control, and initial timing acquisition. Simulation results show that the performance of the proposed parallel processing searcher employing the presented pseudo‐random noise sequence outperforms that employing a preamble sequence in the IEEE 802.15.3a DS‐UWB proposal.