具有感应反馈环的超高频RFID标签天线设计

针对标签天线在RFID系统中的重要性,基于微带天线设计和电磁场散射理论,设计和分析了一种具有感应反馈环的超高频段RFID标签天线。天线的谐振频率为915 MHz,尺寸为78 mm×23 mm,天线显示近线性相位特性,在电压驻波比小于2的条件下,天线的阻抗带宽为100 MHz。可以通过调整感应反馈环的长度来调整天线的谐振频率,天线的增益为2.5 dBi左右。通过仿真和测量可知,这种天线能较好地满足RFID超高频段标签的要求。     

一种基于平面八木天线的小型化宽带滤波天线

设计了一种基于平面八木天线的小型化宽带滤波天线。平面八木天线由偶极子天线、引向器和反射器组成,其中反射器由地板充当。通过引入一个多模谐振器,使整个天线实现滤波响应。与传统的八木天线相比,所设计的滤波天线具有更宽的带宽,并且对高次谐波的抑制良好(抑制至16 GHz),同时在通带边缘体现出较高的选择性。仿真结果表明,该滤波天线的阻抗带宽为5.4~7.0 GHz,并在此带宽内实现了稳定的增益,平均增益约为3.7 dBi。滤波天线的整体尺寸为0.5λ_0×0.7λ_0(W×L),其中λ_0为中心频率6 GHz在自由空间的波长。     

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。     

类Minkowski分形天线的分析与设计

为了实现一款天线在ISM2.4G(2.4～2.483 5 GHz)、Bluetooth、GPS、WLAN(2.4～2.48 GHz)等多频段同时工作,设计了基于分形理论的类Minkowski分形微带天线,方案中对原有的Minkowski分形结构和接地板进行改进。通过仿真分析与优化设计使得天线尺寸缩减至90 mm×71 mm×1.6 mm,谐振频率为2 GHz,工作在0.93 GHz～3.02 GHz频段,相对带宽为105.82%,最大增益可达1.89 dB。最终天线能够进行良好的阻抗匹配,对天线带宽进行展宽,达到了超宽频带天线的要求。     

穿戴式平面印刷PIFA的设计

为了实现穿戴式计算机系统的无线通信,本文对PIFA(平面倒F天线)的结构和原理进行了研究,并实际设计了一种工作于无线局域网 2.45GHz频段的穿戴式平面印刷PIFA,选用特征阻抗为84Ω的微带线进行馈电,一是便于天线穿戴于人体,二是为了实现天线的阻抗匹配;实际制作的天线尺寸为40×40×2mm3,在中心频率2.45GHz处获得1.5%的相对阻抗带宽,增益达2.7dBi;从回波损失曲线和辐射方向性图两个方面将实际制作的PIFA的测量结果与CST仿真结果进行了对比分析,结论是:采用PIFA天线具有小尺寸和低剖面结构的优点,且加工简单、成本低,可用于穿戴系统的无线通信设备.     

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。     

一种超宽带能量收集整流天线设计

为了更好地利用空间无线电波RF能量,设计了一款覆盖谐振频率为1～14 GHz宽带天线,并针对2.4 GHz进行整流天线设计.天线主体为一个圆形贴片,在地面通过开圆形槽的方式,改变辐射单元表面电流强度,实现宽带谐振和增强辐射的作用.天线在2.4 GHz处为最佳谐振点,此频段对应的最大增益为6.26 dBi.为了使整流天线...     

一种超高频 RFID 标签天线结构分析

本文对一种超高频 RFID 标签天线结构进行了仿真分析,优化后的标签天线在负载芯片时,功率反射损耗小于-10dB 的频率范围是900MHz-931MHz,我国和美国允许的频段都包括在内,并且在915MHz 达到最小值-37dB.标签天线能够全向辐射,其远场的增益是2.08dBi.文中讨论了天线各部分尺寸对天线性能的影响,为优化天线的阻抗提供了依据.     

一种应用于微波探测的双频天线的设计

为增加火灾探测天线频带范围,基于微带贴片天线,采用凹槽加载技术,设计了中心频率在Ku(12.4～18.0 GHz)波段的双频微带单元天线.利用HFSS软件对其建模、仿真及优化,结果表明,该单元天线在14.8 GHz和16.1 GHz时回波损失达到最小值,且回波损失小于-10 dB的带宽分别为600MHz和390 MHz.利用该单元天线,进而设计了一款2×2阵列天线,实测结果表明:该阵列天线具有很好的双频谐振特性,在14.3～14.9 GHz和15.7 ～16.1 GHz频带内既保留了原单元天线好的回波损耗特性,又提高了增益,使两个频段最大增益分别达到13.7 dBi和11.3 dBi.     

穿戴系统中的天线设计

采用U型缝加载技术,设计了一种用于穿戴系统的双频平面倒F天线(PIFA),分别工作于GSM(全球通)的900 MHz和WLAN(无线局域网)的2.45 GHz频段,两个频段的相对阻抗带宽分别为10%和5%;在两个谐振频点处,天线的增益分别为0.4 dBi和1.7 dBi.天线具有低剖面结构、重量轻、结构简单等优点,完全满足穿戴系统中长、短距离无线通信要求.     

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。     

A compact implantable RFID tag antenna dedicated to wireless health care

Implantable tag antennas are an integral component of contemporary pervasive patient monitoring setups envisioned to reduce the medical errors and improve the quality of health care facilities. These tags, embedded into the human body, transmit critical patient information to the external equipment via a wireless communication link. This research article presents an implantable compact folded dipole antenna of size 10 mm × 15 mm × 2 mm, designed to operate in the industrial‐scientific‐medical band (2.4‐2.48GHz). A three‐layered phantom representing the human arm is used to evaluate the subcutaneous antenna performance. The tag antenna embedded in the middle of the fat layer offers a maximum gain of ?16.3 dBi. The tag antenna performance as a function of implant position and phantom dimensions is analyzed. Link budget calculations show that with the achieved antenna gain the link power exceeds the required power by 38.37 dBm, and hence wireless communication is viable.     

Novel broadband bow‐tie antenna with high‐gain performance using electromagnetic coupling feed

A novel broadband bow‐tie antenna with high‐gain performance throughout the operating band is proposed and investigated in this article. This folded sectorial bow‐tie antenna is fed by a Г‐shaped strip balun, and the electromagnetic coupling feed mechanism is easy to optimize the impedance matching. The study of proposed antenna performance with different geometric parameters has been conducted. The final design is fabricated and measured, and the results exhibit a good impedance bandwidth of approximately 93.3% for VSWR≤2 ranging from 1.35 to 3.71 GHz, stable gain of 8.43‐10.02 dBi, and unidirectional radiation patterns over the whole operating band. Broadband coverage, stable high‐gain performance, and the simple structure make this antenna an excellent candidate for wireless communication systems.     

一种新型3G系统超宽带室内双向天线研究

设计了一种用于第三代移动通信系统的新型室内双向天线。通过采用渐变球激励的形式,解决了环形天线平衡馈电和阻抗匹配的问题,在节省复杂匹配网络的同时得到了很宽的工作带宽,不需附加额外的匹配网络,天线电压驻波比小于1.5时,阻抗带宽达到100%。天线工作在800 MHz~2 500 MHz,低频段增益可达5 dBi,高频段增益可达8 dBi,满足2G和3G移动室内通信在商务写字楼和宾馆酒店走廊两侧覆盖要求,与现有采用全向天线覆盖的方法相比可有效降低室内移动通信网络的建设成本,提高整个通信网络的容量和质量。     

Additively manufactured trapezoidal grooves for wideband and high gain Ku‐band antenna

Grooves around aperture antennas are known to be instrumental in obtaining directive antenna patterns. The shapes of the grooves are often restricted to rectangular or triangular due to manufacturing difficulties in traditional metal machining, and because of this reason, the effect of groove shape on antenna performance is often overlooked. The aim of this study is to analyze different groove shapes with the help of additive manufacturing. Waveguide slot fed, dual cavity aperture antenna with grooves is designed and the effect of groove shapes on antenna performance is studied at Ku band. Two antennas with and without grooves are built using 3D printing technology. Measured antenna performance reveals 5 GHz bandwidth covering 10 to 15 GHz for Ku‐band satellite communications and part of the X‐band applications. Proposed antenna achieves 13.25 dBi peak gain at 14 GHz and the gain is better than 11.25 dBi over the entire Ku‐band uplink and downlink frequency bands.     

Metamaterial‐based antennas for integration in UWB transceivers and portable microwave handsets

Two planar antennas based on metamaterial unit‐cells are designed, fabricated, and tested. The unit‐cell configuration consists of H‐shaped or T‐shaped slits and a grounded spiral. The slits essentially behave as series left‐handed capacitance and the spiral as a shunt left‐handed inductance. The unit‐cell was modeled and optimized using commercial 3D full‐wave electromagnetic simulation tools. Both antennas employ two unit‐cells, which are constructed on the Rogers RO4003 substrate with thickness of 0.8 mm and ε_r = 3.38. The size of H‐shaped and T‐shaped unit cell antennas are 0.06λ₀ × 0.02λ₀ × 0.003λ₀ and 0.05λ₀ × 0.02λ₀ × 0.002λ₀, respectively, where λ₀ is the free–space wavelength. The measurements confirm the H–shaped and T–shaped unit‐cell antennas operate across 1.2–6.7 GHz and 1.1–6.85 GHz, respectively, for voltage standing wave ratio (VSWR) < 2, which correspond to fractional bandwidth of ～140% and ～ 145%, respectively. The H‐shaped unit‐cell antenna has gain and efficiency of 2–6.8 dBi and 50–86%, respectively, over its operational range. The T‐shaped unit‐cell antenna exhibits gain and efficiency of 2–7.1 dBi and 48–91%, respectively. The proposed antennas have specifications applicable for integration in UWB wireless communication systems and microwave portable devices. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:88–96, 2016.     

Millimeter‐wave antenna with wide‐scan angle radiation characteristics for MIMO applications

A three‐element quasi Yagi‐Uda antenna array with printed metamaterial surface generated from the array of uniplanar capacitively loaded loop (CLL) unit‐cells printed on the substrate operating in the band 25‐30 GHz is proposed. The metamaterial surface is configured to provide a high‐refractive index to tilt the electromagnetic (EM) beam from the two dipole antennas placed opposite to each other. The metamaterial region focuses the rays from the dipole antenna and hence increases the gain of the individual antennas by about 5 dBi. The antenna elements are printed on a 10 mil substrate with a center to center separation of about 0.5 λ ₀ at 28 GHz. The three‐element antenna covers 25‐30 GHz band with measured return loss of 10 dB and isolation greater than 15 dB between all the three ports. The measured gain of about 11 dBi is achieved for all the antenna elements. The three antenna elements radiate in three different directions and cover a radiation scan angle of 64°.     

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.