一种具有宽带双极化低散射特征的微带阵列天线

针对阵列天线宽带散射缩减设计进行研究,设计了一种基于无源对消技术的低散射阵列天线,该新型微带阵列天线在宽频带内具有双极化低雷达散射截面（RCS, Radar Cross Section）性能;对基于两种散射性能不同的单元组成阵列的RCS性能进行了理论研究,进行了单元的散射幅度和相位对阵列RCS的影响分析;提出了一种加载T型缝隙的新型微带天线结构,该单元结构的辐射性能与散射性能能够进行独立调控和综合优化,该单元与传统微带贴片单元具有相似的辐射特性,并可在宽频带（带内和带外）内与传统微带单元产生有效相位差;将传统微带单元和加载T型缝隙的新型微带单元组成4×4阵列天线,仿真结果表明,提出的阵列天线在3GHz～7GHz（相对带宽80%）频带内实现了同极化RCS缩减,在3.3GHz～7GHz（相对带宽71.8%）频带内实现了交叉极化RCS缩减,缩减峰值分别为16.3dB和36.3dB,带内RCS缩减均值分别为14.1dB 和17.6dB;与传统微带阵列天线相比,提出的阵列天线增益下降小于0.1dB;提出的微带阵列天线具有高效率辐射和宽频带双极化低散射性能,为低散射阵列天线设计提供了新的思路。     

一种新型EBG低剖面的微带基站天线设计

设计了一种工作在LTE及5G频段的新型微带基站天线,该天线通过在反射背板上加载新型EBG的方法,既满足天线的工作带宽及辐射增益,还达到了降低天线剖面高度的作用,将天线的高度从40 mm降低至22 mm。该基站天线的工作频带为1.65～3 GHz,阻抗带宽达到了1.351 GHz,阻抗带宽达到58%,在2.1 GHz频率上天线的方向性系数为8.13 dBi。研究证明,贴片在反射背板上加载EBG结构可以有效降低天线高度。     

一种双频定向毫米波天线设计

本文基于特征模理论,设计出一款易于制造的低成本双频毫米波阵列天线的单元,其在24.07GHz～25.35GHz和41.75GHz～43.76GHz具有较好的定向辐射特性,增益在低频端大于6dbi,高频端大于7dbi。通过分析特征模理论,在圆形贴片上通过开缝引入磁流辐射,弥补贴片天线原有的模式方向图出现多瓣的情况,以达到双频方向图近似一致,该双频贴片天线制造简单成本较低,非常适合双频定向的应用环境。     

应用于WSN的小型化微带天线的研究

基于目前对WSN(无线传感器网络)的需求,本文设计了一种工作在2.4GHz的小型化的矩形开槽微带贴片天线,由于采用了曲流技术,该天线比一般微带天线要小,当工作在2.4GHz时,其导波波长为70mm,天线尺寸为29mm×29mm,长宽均为导波波长的0.4倍。仿真与测试结果表明,实验结果与仿真结果基本吻合。天线的-10dB带宽为24MHz(2.38GHz-2.404GHz),天线的辐射特性较好,在-10dB带宽内,辐射增益均大于0dBi,而且在中心频率2.4GHz处达到最大值6dBi。     

小型化低剖面全向滤波天线设计

设计了一个小型化全向微带滤波天线。天线由带通滤波器和微带天线组成,二者共用一个地平面以减小尺寸且采用缝隙耦合方式连接,带通滤波器蚀刻在微带贴片天线的馈线位置处,引入选频滤波功能,在输入馈线前端添加一个横向矩形贴片使整个系统达到良好的阻抗匹配。与传统的微带天线相比,所设计的滤波天线在不改变尺寸大小的基础上引入了选频滤波功能,在通带边缘体现出较高的选择性。仿真与测试结果表明,该滤波天线的阻抗带宽为2.31 GHz～2.56 GHz,且通带内增益平缓,平均增益约为2.1 dBi,在工作频段内呈全向辐射特性。     

基于缝隙耦合的微带天线设计

能够同时适用于射频识别、全球微波无线互联网和无线局域网这几大主流物联网通信技术标准的宽频天线的设计要求越来越高,比如体积小、成本低等,而微带天线体积小、剖面低且可集成化程度高,适合大批量生产,但其频带较窄,使用范围受到限制。为此,提出了一种紧凑型宽频带微带贴片天线。该天线引入了L型缝隙和三角形缝隙,仿真结果表明,天线-10 dB阻抗带宽可达到100%,其工作频带为1. 5 GHz～4. 3 GHz;轴比带宽为3. 4 GHz～3. 8 GHz,圆极化带宽为11%;在该范围内的增益都在3 dB以上;整个工作频带范围内都实现了宽频带、高增益等特性,适用于射频识别、蓝牙、WLAN等频段。     

GIS局部放电检测的有源外置UHF传感器设计

针对传统无源外置局部放电超高频(UHF)传感器频带窄、增益低、容易引入噪声的问题,研究并设计了基于有源集成天线(AIA)技术的有源外置传感器.传感器通过宽频带天线接收局部放电产生的电磁波信号,在天线介质板上直接由有源对数检波器放大信号进行包络检波,省去了传统设计中的平衡不平衡转换与射频传输线,降低天线前端的匹配损耗,改善传感器的频带、噪声和增益.测试结果表明:传感器中心频率为900 MHz,驻波比小于2的频带为730 MHz ～ 1.05 GHz,传感器输出信号峰值为5V,频率为2～10 MHz.该传感器抗干扰能力强,增益高,适合GIS局部放电的检测.     

S波段微带均衡器的设计与实现

设计了一种用于低噪声放大器后端的微带增益均衡器,通过对其结构进行理论分析、设计、仿真及加工调试,完全实现了所需的目标幅频曲线,改善了输出增益平坦度。根据测试结果,该微带均衡器工作于2 GHz-3 GHz频带内的幅度在2 GHz频点最大衰减3.5 dB,3 GHz频点最小衰减0.5dB,并随频率呈递增特性,且输入输出回波损耗超过14 dB。     

基于高频结构仿真器和神经网络的双面双频宽带偶极子天线设计

为了快速地设计一款应用于无线局域网络(WLAN)的双面结构的具有双频段、宽频带、小型化特性的偶极子天线,将偶极子贴片分别放置于介质基板的两侧,并采用微带巴伦线馈电的方式,以实现更好的宽带匹配。在偶极子的两臂分别开槽,实现小型双频特性,以满足WLAN的2.45GHz和5.49GHz的双频要求。整个天线的尺寸为28mm×44mm×1.6mm。并且利用电磁仿真软件高频结构仿真器(HFSS)和神经网络(NN)联合优化天线的尺寸,加快设计过程。仿真结果表明,当S11小于-10dB时,天线在低频和高频的带宽分别可以达到470MHz(2.29~2.76GHz)和3650MHz(4.96~8.61GHz);当S11小于-14dB时,天线在低频和高频的带宽分别可以达到210MHz(2.36~2.57GHz)和770MHz(5.13~5.9GHz)。而且该天线的方向图具有良好的全向性,实物测量与仿真结果的一致性良好,可以满足WLAN的需要。     

一种宽频带复合天线设计

针对多系统载体天线数量多的问题,提出了一种基于印刷振子结构的宽频带共口径复合天线设计方法;通过两种不同形式的印刷偶极子进行共口径设计：采用平面印刷偶极子结构完成宽带高增益线极化天线,通过宽带定向耦合器实现了天线和差方向图辐射;采用十字印刷偶极子实现低增益天线的圆极化辐射;两种天线单元印刷在同一微波介质上,通过优化天线单元布局,相对位置关系和增加金属隔离环等措施,降低天线之间的相互影响,实现共口径复合天线性能满足工程应用要求;加工了天线样机,测试结果表明线极化天线在工作频带1.2～1.8 GHz范围内和差通道电压驻波比小于1.8,和通道增益大于13.5 dBi,方位差波束零值深度小于-25 dB,圆极化天线在工作频带1.2～1.8 GHz范围内电压驻波比小于1.6,增益大于6.5 dBi,轴比小于2.5 dB,与计算结果基本一致;复合天线可以满足多种无线通信系统的需求,减少了天线数量,有效节省载体平台空间,同时具有结构简单紧凑、剖面低、易于工程实现等特点,具有广阔的应用前景。     

汽车雷达微带阵列天线设计

为提高汽车雷达性能,设计了一款汽车雷达天线,采用4×8微带阵列天线形式,设计中心频率为24.1 GHz,采用指数加权的方式设计馈电网络,以降低副瓣.在HFSS电磁仿真平台上对其进行仿真、优化.仿真结果显示天线最大增益为21.4 dBi,副瓣电平低于-15 dB,H面半功率波束宽度约为10°,在24 ～ 24.5 GHz频段性能稳定.天线整体长约70 mm,宽约36 mm,体积小.将该天线应用于汽车雷达可以探测车辆和障碍物的速度、距离、角度等信息,从而实现防撞预警、盲点侦测等功能.     

A CPW‐fed band notched wideband circularly polarized ZOR antenna based on CRLH‐TL approach

This article presents design and analysis of three wide band zeroth‐order resonance antennas (antennas I, II, and III) using composite right and left‐handed transmission line (CRLH‐TL) approach. Coplanar waveguide technology, single layer via‐less structures are used to have the design flexibility. The bandwidth characteristics are analyzed by using lumped parameters of CRLH‐TL. By introducing a simple slot in the ground plane of antenna I both bandwidth enhancement and circularly polarization characteristics are achieved in antenna II. Another quarter wave L‐shaped slot has been introduced in the ground plane of antenna II to introduce a notch band in the frequency response of antenna III. Achieved measured 10 dB return loss bandwidth of antenna I and antenna II are 960 (3.3‐4.26 GHz) and 2890 MHz (2.77‐5.66 GHz), respectively. Antenna III offers measured 10 dB return loss bandwidth of 3220 MHz (2.32‐5.54 GHz) with a band notch from 2.39 to 2.99 GHz that isolates the 2.4 GHz WLAN and 3.5 GHz WiMAX band. Antenna II and antenna III have circular polarization property with measured axial ratio bandwidth of 440 MHz. The measured peak realized gain of antennas II and III is around 1.53‐2.9 dBi.     

Design of dual‐band microstrip patch antenna with right‐angle triangular aperture slot for energy transfer application

This work focusing on the dual‐band antenna design with rectifying circuit for energy transfer system technology for enhancement gain performance. The air gap technique is applied on this microstrip antenna design work to enhance the antenna gain. The work begins with designing and analyzing the antenna via the CST Microwave Studio software. After validation on acceptable performance in simulation side is obtained, the return loss, S₁₁ of the antenna is measured using vector network analyzer equipment. The rectifier circuit is used to convert the captured signal to DC voltage. This projected dual‐band antenna has successfully accomplished the target on return loss of ?44.707 dB and ?32.163 dB at dual resonant frequencies for 1.8 GHz and 2.4 GHz, respectively. This proposed antenna design benefits in low cost fabrication and has achieved high gain of 6.31 dBi and 7.82 dBi for dual‐band functioning frequencies.     

Design and Analysis of Novel Antenna for Millimeter-Wave Communication

At present, the microwave frequency band bandwidth used for mobile communication is only 600 MHz. In 2020, the 5G mobile Communication required about 1 GHz of bandwidth, so people need to tap new spectrum resources to meet the development needs of mobile Internet traffic that will increase by 1,000 times in the next 10 years. Utilize the potentially large bandwidth (30∼300 GHz) of the millimeter wave frequency band to provide higher data rates is regarded as the potential development trend of the future wireless communication technology. A microstrip patch implementation approach based on electromagnetic coupling feeding is presented to increase the bandwidth of a dual-polarized millimeter-wave antenna. To extend the antenna unit's impedance bandwidth, coplanar parasitic patches and spatial parallel parasitic patches are used, and a 22 sub-array antenna is developed using paired inverse feed technology. The standing wave at the centre frequency of 37.5 GHz is less than 2 GHz. The antenna array's relative bandwidth is 6.13 percent, the isolation is >30 dB, the cross-polarization is −23.6 dB, and the gain is 11.5 dBi, according to the norm. The proposed dual-polarized microstrip antenna has the characteristics of wide frequency bandwidth, large port isolation, low cross-polarization, and high gain. The antenna performance meets the general engineering requirements of millimeter-wave dual-polarized antennas.     

Meander line MIMO antenna for 5.8 GHz WLAN application

A four port compact low profile planar MIMO antenna with meander line radiators and with polarization diversity effect has been proposed to cover 5.8 GHz wireless local area network application. The proposed MIMO antenna has ?10 dB impedance bandwidth of 1.4 GHz (5.3–6.7 GHz) along with the compact size of 38 × 38 mm² and an envelope correlation coefficient (ECC) of less than 4 × 10^?4 in the whole band. The proposed antenna resonates at 5.8 GHz frequency, having return loss of ?43.2 dB. The isolation between diagonal and opposite ports is more than 10 and 12 dB, respectively, in the presented frequency band. The total active reflection coefficient frequency response shows more than 1.0 GHz of bandwidth in the whole band. The antenna gain is more than 4.0 dBi in the operating frequency band. The radiating elements are very close to each other to make the design very compact.     

A Multiband antenna using plus‐shaped fractal‐like elements and stepped ground plane

A multiband planar symmetrical plus‐shaped fractal monopole antenna with stepped ground plane is presented in this study. Measured results show that the proposed antenna operates with 10 dB return loss bandwidths from 1.630 to 1.88 GHz and from 4.5 to 8.5 GHz covering The Global System for Mobile Communications (GSM) 1800 MHz 2G spectrum band, 4400 to 4900 MHz 5G spectrum band adopted by Japan and China for future 5G communication in sub‐6 GHz band, 5.15 to 5.925 GHz LTE band 46, WLAN IEEE 802.11 y/a/h/j/n/P bands, and 5.8 to 7.707 GHz military band. The antenna gain varies between 1.73 and 1.97 dB in lower band and 3.6 to 5.05 dBi in upper band with radiation efficiencies more than 90% in lower band and more than 80% in upper band. The antenna has more than 64 and 28 dB isolations between the copolar and cross‐polar radiation patterns in the lower and upper bands, respectively.     

Wideband microstrip‐fed tapered slot antennas and phased array

Two wideband tapered slot antennas are designed, fabricated, and tested. The first antenna, which is fabricated on a high dielectric constant substrate (?_r = 10.2), shows a measured return loss of better than 10 dB from 1.6 to 12.4 GHz (7.7:1 bandwidth), and an antenna gain varying from 3.6 to 7.8 dBi. The second antenna is built on a low dielectric constant substrate (?_r = 2.2), and demonstrates return loss of better than 10 dB from 1.8 to 15.2 GHz (8.4:1 bandwidth). The second antenna also has improved antenna gain, from 5 to 15.6 dBi, and is used to build a wideband 1 × 4 H‐plane phased array with a total gain of 9–17 dBi and a beam steering angle of ±15° from 3 to 12 GHz. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007.     

A multistate high gain antenna based on metasurface

A multi‐state high gain antenna based on metasurface is proposed. The antenna is composed of two stacking layers and a ground plane. The metasurface is constituted by two layers with the same size. And both of the two layers contain a copper patch array which is formed by 4 × 4 square copper cells uniformly distributed along x and y directions. The metasurface antenna is excited by the aperture coupled structure. The structure is consists of an anomaly microstrip line and a narrow slot etched in the ground plane. Genetic algorithm (GA) is adopted to optimize all the parameters and obtain the best performance of the metasurface antenna. By appropriately choosing the dimensions of the antenna, the proposed antenna can be achieved with the impedance bandwidth (RL≥10 dB) of about 340 MHz (7.8% at 4.36 GHz), 180 MHz (3.6% at 5.02 GHz), and 2800 MHz (41.1% at 6.81 GHz). The peak gain of the proposed antenna is 10.1dBi, 6.9 dBi, and 10.5dBi at 4.26 GHz, 5 GHz, and 7 GHz. In addition, the proposed metasurface antenna can work in multistate, which makes it an excellent candidate for practical applications.     

An UWB trapezoidal rings fractal monopole antenna with dual‐notch characteristics

An ultra‐wideband planar fractal monopole antenna with dual‐notch characteristics is presented in this article. The microstrip fed antenna consists of nested trapezoidal rings and defected ground plane. Measured results show that the proposed antenna operates with a 10 dB return loss bandwidth from 2.2 to 10.8 GHz with notch bands at (2500‐2690) MHz and (3300‐4200) MHz covering LTE 2500, WiMAX and part of C‐band.     

Circular microstrip antenna with off‐centered Y‐slot

A novel dual‐frequency broadband design of a single‐layer single‐feed circular microstrip antenna with an off‐centered Y‐slot is demonstrated in this communication. By selecting a suitable location of the Y‐slot in the circle, the proposed antenna on glass epoxy FR‐4 substrate not only resonates efficiently at two closely spaced frequencies (2.736 and 2.868 GHz) but also offers improved bandwidth (210 MHz or 7.5%) in comparison with a conventional circular microstrip patch antenna (～2%). From the measured results, almost identical broadside radiation patterns are obtained at two resonant frequencies, and the variation of less than 1 dBi in gain values is achieved in the frequency range where broadband behavior is observed. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011.