低轨卫星通信终端微带天线设计与实现

针对低轨卫星通信系统中微带天线的特性要求,首先利用高频结构仿真软件HFSS建立微带天线模型,并对该模型运用电磁理论和优化理论进行仿真优化,得到了最佳的微带天线结构和电参数.然后根据设计参数研制了符合要求的中心频率为398 MHz的微带天线,并且缩减尺寸至可以植入卫星通信中的便携式终端设备.利用矢量网络分析仪对该天线各参数实测结果表明,研制的微带天线的性能与实际要求的指标吻合,证明了设计的有效性.     

适用于太赫兹通信系统的E形微带天线设计

设计了一种用于太赫兹通信系统的E形微带天线,并利用高频结构仿真软件(HFSS)对设计天线进行仿真。E形微带天线通过在矩形微带天线上加载两条平行缝隙槽以获得宽频带特性。仿真结果表明设计天线的-10dB相对带宽达到29%(从1.394THz到1.87THz),同时给出了该天线的驻波比曲线图和增益曲线图。研究结果显示该E形天线结构简单,能够满足无线通信系统的要求。     

基于双三角形谐振环结构左手材料的矩形微带贴片天线

设计了一种双三角形谐振环结构的左手材料,通过理论计算和仿真实验证明了其具有电磁左手材料性质;将双三角形谐振环结构的左手材料加载在矩形贴片微带天线上,并给出了矩形微带贴片天线的结构参数;利用HFSS仿真软件对比了加载左手材料前后矩形贴片微带天线的性能,仿真结果表明,左手材料的加载提高了天线的带宽,增大了天线的增益,有效地抑制了旁瓣。     

一款用于无线胶囊内窥镜的微带天线设计与仿真

基于时域有限差分方法,采用真实人体数字三维模型,仿真了天线在人体消化道内辐射情况,分析了天线结构参数对天线辐射性能的影响。针对无线胶囊内窥镜(Wireless Capsule Endoscopy,WCE)在人体消化道内工作特点,设计了一款能够用于发送消化道内图像数据的WCE微带天线,该微带天线谐振频率为500 MHz,输入回波损耗S11-10 dB时相对带宽为8%,带内VSWR2.0,最后采用仿真优化后的结构参数和材料制作了天线,并进行了测试,得到了满足实际应用要求的微带天线。     

一种Peano结构的圆极化微带天线设计

在天线结构优化设计中,为了改善电磁带隙结构下阵元间距过大造成天线阵极化特性和增益性能下降的问题,提出设计了一种Peano结构下的圆极化微带天线.使用直接传输方法分析有限周期的一阶Peano结构的表面波带隙,将电磁带隙结构放在微带天线周围,通过减小电磁带隙结构和天线的间距,优化天线结构和天线的参数,缩小阵元之间的间距.仿真结果表明,与传统的电磁带隙结构微带天线相比,改进设计能有效减小圆极化天线阵中阵元间距,抑制阵元之间的互耦,提高阵元的方向性和天线阵性能.     

一种卫星导航终端多频圆极化微带天线的设计

设计了一种覆盖北斗一代发射L频段、接收S频段、北斗二代B1频段和GPS的L1频段多频圆极化微带天线。天线采用叠层结构来实现多频段的覆盖,各频段采用单点馈电的方式,利用辐射贴片切角实现天线的圆极化特性。天线进行了仿真设计、实物制作、指标测试和功能测试,结果表明,该天线工作带宽、圆极化特性和增益均满足卫星导航终端天线的指标要求,能够应用于北斗/GPS卫星导航终端。     

新型电磁材料结构的微带天线设计

使用基于Matlab的遗传算法程序结合HFSS仿真,设计了一种具有表面波带隙特性的新型电磁材料结构,将其用于微带天线能够抑制表面波、提升增益.对优化记录进行保存和查询,有效地加快了算法优化进程.通过仿真对比表明:添加该新型电磁材料结构后的微带天线工作在5.8 GHz时,增益提升1.8dB,背瓣降低3.8dB,提升了天线对电磁信号的采集能力.     

新型锯齿结构微带天线在整流天线中的应用

提出了一种新型带有V形锯齿结构的圆形微带天线,相比于传统的圆形微带天线,该结构微带天线在2GHz的S11值能够达到-26.9dB,二次谐波S11值能够达到-0.2 dB,三次谐波S11值能够达到-3 dB。由于这种良好的抑制高次谐波的作用,在组成整流天线时,可以省掉结构复杂、体积较大的滤波器。并且采用这种结构的天线,具有采用分形技术设计微带天线所获得的缩小天线尺寸的效果。对由该结构组成的整流天线进行仿真和实验测试,获得了超过2.7 V的DC电压,证明了其应用到整流天线中的可行性。     

一种易调谐的小型GPS微带天线设计

提出了一款新颖的易调谐小型GPS微带天线结构。采用正方形贴片作为辐射单元,通过切角微扰实现右旋圆极化辐射;在贴片中心开槽和四周开缝,利用贴片曲流技术减小天线的尺寸;使用同轴中心馈电加载微带匹配段,实现阻抗的匹配。文章给出了天线的设计思路,并进行了大量的电磁仿真优化,最终对天线进行了加工实验。实验结果表明,在设计的频带内,天线具有较好的阻抗匹配和圆极化辐射特性。该天线具有结构紧凑、易于调谐的特点,具有良好的应用前景。     

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。     

一种宽频带四单元微带天线阵设计*

综合运用了H型缝隙耦合馈电技术和引入空气层技术展宽了天线的频带,设计出一个工作在Ku波段的宽频带微带天线单元并组成四单元阵列。该天线由两层介质板构成,并利用180°反相馈电抑制了高次模的耦合激励,降低了交叉极化电平。使用三维电磁场仿真软件(Ansoft HFSS)对微带天线进行仿真优化,仿真结果表明,天线单元性能良好,相对阻抗带宽(S11≤-10 dB)为8.5%,增益为8.05 dB。四单元天线阵列相对阻抗带宽(S11≤-10 dB)达到16.6%,增益为13.7 dB。天线阵列性能良好,设计方法具有很好的可扩展性。归纳总结出的介电常数计算式也具有普遍性。     

用于卫星通信的Ku波段宽带双频双极化微带天线阵

利用口径耦合馈电、错位倒相馈网技术和单层微带贴片结构设计出一种用于卫星通信的Ku波段宽带双频双极化微带四元天线阵。用电磁仿真软件CST2008对天线阵的电特性进行了仿真和优化。四元天线阵实测结果表明:水平极化端口在11.21GHz～13.47GHz频率范围内VSWR燮1.5,相对阻抗带宽为18.3%;垂直极化端口在13.43GHz～14.88GHz频率范围内VSWR燮1.5,相对阻抗带宽为10.24%。工作频带内两端口隔离度<-35dB,最大增益为13.2dB,与仿真结果一致。     

Prediction of slot‐position and slot‐size of a microstrip antenna using support vector regression

This article presents a synthesis modeling scheme of rectangular microstrip antenna with support vector regression (SVR) scheme. Here, radiating patch and ground surface is loaded with two asymmetrical slots and two symmetrical slots, respectively. The position of the slots on the radiating patch as well as the size of the slots on the ground surface are predicted using SVR model and artificial neural network (ANN) model. A good convergence rate has been addressed in synthesis model by employing the adaptive step‐size. A comparison between SVR model and ANN model is presented where SVR is more accurate and faster than ANN. The suggested SVR approach is also validated by fabricating and characterizing a prototype of microstrip antenna. A very good agreement is observed in measured, simulated, and predicted results. The predicted microstrip antenna has displayed quite good agreement between measured and simulated performance parameters.     

用双负材料改善微带天线阻抗带宽

针对微带天线带宽较窄的问题,采用基于有限元法的HFSS软件,设计1种以双负材料为衬底的微带天线．仿真计算其反射系数,并给出测试结果．对仿真与测试结果进行比较分析表明,相对于同样尺寸以普通材料为衬底的微带天线,以双负材料为衬底的微带天线的带宽展宽约为50％,在中心频率的相对带宽也达到16．6％．     

Bandwidth-reconfigurable filtering microstrip patch antenna using contactless varactor-loading scheme

A bandwidth (BW)-reconfigurable filtering microstrip patch (MP) antenna is investigated in this paper. Two pairs of slots with different lengths are etched on the patch to not only bring two radiation nulls for good filtering performance but also generate additional high resonant mode for extending the operating BW of the antenna. A contactless varactor-loaded microstrip line embedded in the middle layer of the two stacked substrates of the MP antenna is constructed as a tuning structure so that the MP mode and the lower radiation null can be adjusted simultaneously. As a result, the fractional BW (FBW) of the filtering antenna can be reconfigured with a BW agility of 55.3% while the high selectivity is maintained. For demonstration, a prototype is implemented and tested. The simulated and measured results with good agreement are presented.     

Design optimization of a pattern reconfigurable microstrip antenna using differential evolution and 3D EM simulation‐based neural network model

In this work, design optimization of a varicap diode loaded antenna consisting of four identical rectangular microstrips is presented as a pattern reconfigurable antenna at 5.2 GHz. The microstrips are printed on the front of a FR4 substrate with the dimensions of 40 mm × 25 mm and ε _r = 4.6, h = 1.58 mm and probe‐fed via a coupling using a rectangular microstrip line symmetrically placed between them. In first stage, S₁₁ of the antenna are obtained as its real and imaginary parts as continuous functions of geometry of the microstrip components within 3 to 7 GHz using multi‐layer perceptron (MLP) trained and validated by 3D EM simulated data. In order to determine the most suitable (MLP) architecture and training algorithm, 20 different MLP architectures are tested. Then, S₁₁ are optimized with respect to the geometry parameters using differential evolution algorithm and MLP based model. The antenna is prototyped with the optimally selected parameters and measured. From the comparison of simulation and measurement results, it can be observed that the measurement results agree with the simulation results, thus it can be concluded that the proposed antenna is a simple and successful design subject to the design purposes with together its design methodology.     

树枝状结构超材料在微带天线上的应用仿真

针对普通微带天线增益低、方向性差的缺点,提出一种树枝状结构超材料微带天线模型,为提高性能,利用以有限积分为主的CST软件对树枝状结构负磁导率微带天线模型和树枝状结构左手材料覆层微带天线模型进行了仿真研究。仿真结果表明,相对于普通微带天线,负磁导率材料基板天线增益提高了,并使有效辐射功率得到提高。同时,树枝状结构左手材料覆层天线的增益提高了1.2dB,相当于天线的有效辐射功率提高了31.8%,E面和H面主瓣半功率波束宽度分别收缩了45.8°和44.8°。树枝状结构负磁导率材料和左手材料可以抑制天线激发的表面波,对天线发射的电磁波进行会聚效率更高。新型天线可用于导弹、卫星及飞机飞行器等。     

A wideband frequency agile fork‐shaped microstrip patch antenna with nearly invariant radiation patterns

A wideband frequency agile fork‐shaped microstrip patch antenna is presented. Its operating frequency is tuned by incorporating four varactor diodes, which are placed symmetrically on the patch. The operating mechanism of this antenna is also briefly discussed. The full wave analysis simulated results show that the operating frequency can be tuned from 1.47GHz to 1.84GHz (frequency agility of 26.50%) with nearly invariant radiation patterns while achieving acceptable gain throughout the operating frequency range. Finally, the proposed fork‐shaped antenna was fabricated and measured for its impedance matching and gain radiation patterns. Measurement results show reasonable agreement with the simulated data. © 2016 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:623–632, 2016.     

Analysis of one wide‐band and high gain patch microstrip antenna using the FDTD method

We present results of a recent investigation into a wide‐band and high gain patch microstrip antenna using the finite‐difference time‐domain (FDTD) method. The substrate–superstrate resonance technique was used to increase the antenna element gain. An aperture‐coupled rectangular patch microstrip antenna with two superstrate layers was designed, and the effect of the finite ground plane on the gain of the antenna element was analyzed. The antenna was fabricated and tested. The measured results are presented in comparison with the simulated ones. ©1999 John Wiley & Sons, Inc. Int J RF and Microwave CAE 9: 468–473, 1999