一种U型宽带微带天线的设计与制作

对微带天线频带的展宽方法进行了研究,借助于时域有限差分法进行数值计算.经过反复修改设计,选择了在接地板"开窗"的方法,并且贴片设计为"U"型结构.对天线的散射参数、方向图等参数进行了仿真分析;用聚四氟乙烯玻璃漆布敷铜板作为原材料、对天线进行了实际制作;用AV3616XA射频微波网络分析系统对天线进行了测试.均得到了较好的结果,相对带宽达到了27%.     

天线运动参数的自动测量

天线运动参数如天线扇扫范围、天线扇扫速度、天线环扫速度等参数的测量通常采用手动计时器测量.提出了采用计算机及FPGA技术进行天线运动参数的自动测量,介绍了天线扇扫范围、天线扇扫速度、天线环扫速度的测量原理、实现方法并给出了测量电路的电路框图.分析了各参数的软件算法,并给出了计算公式.最后进行了测量误差分析,并给出了实际的测试结果.采用该测量系统减少了测量时间,简化了测量方法,提高了测量精度,解决了天线运动参数的自动测量问题.     

基于FDTD法的小型化微带天线设计

以微带天线小型化为目标,进行设计研究.利用FDTD法对几种平面贴片天线进行分析,通过比较各天线散射参数的频域响应寻找一种既能保持微带天线原有优点,又可实现小型化的方案.使得天线能够满足个人通信手持终端设备对体积和重量的严格要求.     

基于微遗传算法的超宽带天线(阵)优化

为满足天线的不同设计要求,提高设计效率,采用时域有限差分法（FDTD）,并与微遗传算法（MGA）结合,用于超宽带天线的优化设计.分析表明,用微遗传算法比遗传算法收敛快.以TEM喇叭天线为例证明了该方法的有效性.用FDTD分析了超宽带电磁脉冲经同轴线馈电在平行板传输线和超宽带天线中的传输过程,得到了天线的时域信息.由天线的时域信息计算天线的性能参数,再用归一化的性能参数构造适应度函数,最后用微遗传算法优化天线结构.     

基于实测载荷谱的ATP天线梁随机振动疲劳分析

为提高某地铁转向架ATP天线梁结构疲劳寿命,对天线梁结构进行随机振动疲劳分析.依据某地铁天线梁的动应力测试数据,并结合部件焊接接头的S-N曲线,研究天线梁结构的疲劳寿命;建立天线梁结构的有限元分析模型,并在实测载荷谱作用下,对天线梁结构进行随机振动分析与疲劳寿命预测,分析结果表明:天线梁疲劳薄弱部位与基于在线动应力测试的结果一致,不满足设计要求;依据随机振动疲劳分析优化的新型天线梁结构经过线路测试与分析,其结构满足350万公里的运营要求.     

基于隐式参数化模型的地铁车体轻量化设计

为实现地铁新车型前期快速的概念设计和性能评估,引用“分析驱动设计”理念对重庆6号线地铁的MP车体进行了隐式参数化建模;并录入车体的17个主要钣金件进行设计分析。以板厚为设计变量,筛选出模态和刚度对质量相对灵敏度较大的7个车体钣金件,进行基于响应面法的多目标轻量化优化设计;车体的刚度、模态等多项性能指标达到了良好的轻量化效果。研究结果表明：所引入“分析驱动设计”理念的车体隐式参数化建模及基于响应面法的多目标优化方法能应用于车体结构的轻量化设计,具有较好的工程指导意义。     

一种基于超介质的超宽带天线设计

提出一种基于超介质加载的超宽带天线.超介质结构由提供负介电常数的电容加载带(CLS)和提供负磁导率的开口谐振环(SRR)共同构成.针对原始窄带微带天线的特性,使用电磁仿真软件HFSS对超介质进行结构设计,使其能够在超宽带频带内产生均匀分布的多谐振点.对超介质进行电磁参数提取,其同时实现双负特性.研究超介质加载个数对展宽天线带宽的影响,确定加载个数.对天线进行辐射贴片开槽、缺陷地处理,实现多频带融合.最终设计的超宽带天线阻抗带宽达到2.89～12.07 GHz,相对带宽达到127.72％,是原始天线的54倍.对天线进行制作,实测结果与仿真结果基本吻合.     

基于NSGA-Ⅱ的宽带天线匹配网络设计

针对天线宽带匹配网络的设计,各种不同的方法相应地被提出,其中对天线的输入阻抗进行匹配是一种有效的方法.利用精英保留非劣排序遗传算法(NSGA-Ⅱ)设计宽带天线匹配网络,实现网络输入端口反射系数和传输功率增益的多目标优化.仿真实验表明,所设计的宽带天线匹配网络具有随天线阻抗变化灵敏度低的优点,天线效率达到50％以上,证明了NSGA-Ⅱ算法的有效性.     

井下无线数据交换器天线研究与设计

根据石油工业工程需要,研究开发了一套用于井下流量、温度、压力监测的无线数据交换系统,系统通过无线方式从井下提取已采集的数据并实时传送给地面监测系统.在该系统中,天线作为井下无线数据交换的核心部分,起着决定性的作用.文中针对这一应用介绍了天线的设计方法、工作方式及参数计算举例,给出了经过优化设计后的天线各参数值,实验结果验证了其有效性.     

钻孔灌注桩的可靠性设计方法分析

用“校准法”对现行《桥规》桩基可靠度水准进行了校准计算,并确定了桩的目标可靠指标;提出了单桩承载力的表达式和设计参数。     

Bandwidth Numerical Analysis of Triangular Patch Antenna Fed by L-Shaped Probe

IntroductionA triangular patch antenna's major weaknessis its intrinsic narrow bandwidth.Some techniqueshave been suggested for widening its bandwidthsuch as the employmentof a thicker substrate witha coaxial feed[1] ,which will limit the achievablebandwidth due to the increased inductance of thelonger probe. Recently a novel feeding approachemploying an L- shaped probe has been devel-oped[2 ] ,butno numerical analysis has been provid-ed.Physically this L- shaped probe introduces a ca-pacitan…     

拱形基板微带贴片天线性能分析

提出了一种新型微带贴片天线,对不同角度下天线的反射损耗、带宽和方向图进行了仿真.与普通微带贴片天线相比,这种新型天线的相对阻抗带宽(S11衰减到-10dB)一般在20%以上,个别角度下能达到43%,而且方向图有较大变化.     

E型贴片微带天线性能分析

在矩形微带贴片天线的基础上,通过在贴片上开两条对称的缝隙而得到E型贴片.讨论了E型贴片缝隙的长度、宽度和相对位置对天线的输入阻抗、带宽、谐振频率的影响.通过适当的改变缝隙的参数,可以实现宽频带阻抗匹配,减少外围电路设计的复杂性.     

Design of Cross-Shaped CPW-Fed Ultrawideband Slot Antenna

A new design of ultrawideband(UWB) antenna of coplanar waveguide(CPW)-fed is proposed. The antenna is composed of a cross-shaped patch and house-shaped slot with the minimum dimension of 21 mm ×20 mm × 1.6 mm. The analysis of S11, VSWR, radiation pattern and surface current is discussed with HFSS simulation software, and also the effect of parameters is presented. Experimental results show that the bandwidth of the antenna covers 110.67%(3.3—11.6 GHz) of UWB range with return loss better than 10 dB. And the good impedance matching in frequency band confirms the antenna is a good candidate for the application of wireless system.     

Link Budget Analysis for Massive-Antenna-Array-Enabled Terahertz Satellite Communications

Broadband satellite communications can enable a plethora of applications in customer services, global nomadic coverage and disaster prediction and recovery. Terahertz (THz) band is envisioned as a key satellite communication technology due to its very broad bandwidth, astrophysical observation advantages and device maturing in recent years. In this paper, a massive-antenna-array-enabled THz satellite communication system is proposed to be established in Tanggula, Tibet, where the average altitude is 5.068 km and the mean-clear-sky precipitable water vapor (PWV) is as low as 1.31 mm. In particular, a link budget analysis (LBA) framework is developed for THz space communications, considering unique THz channel properties and massive antenna array techniques. Moreover, practical siting conditions are taken into account, including the altitude, PWV, THz spectral windows, rain and cloud factors. On the basis of the developed link budget model, the massive antenna array model, and the practical parameters in Tanggula, the performances of signal-to-noise ratio (SNR) and capacity are evaluated. The results illustrate that 1Tbit/s is attainable in the 0.275—0.37 THz spectral window in Tanggula, by using an antenna array of the size 64.     

Multi-Band Hybrid Mobile Phone Antenna Based on Electromagnetic Coupling

This research presents a multi-band hybrid mobile phone antenna based on electromagnetic coupling,which can be applied to mobile handheld devices, occupying a small board space of 39.7 mm × 15.6 mm on the system circuit board. By adding resonant and coupled branch instead of multi-feed on the traditional bent antenna,this design provides four wide operating bands of 0.772—0.998 GHz, 1.540—1.600 GHz, 1.680—2.270 GHz and2.300—2.690 GHz with the hybrid feature of planar inverted-F antenna(PIFA), L-shape, U-shape and S-shape structures, which cover nine-band, i.e., GSM850, GSM900, GPS1575, DCS1800, PCS1900, IMT200, LTE2300,LTE2600 and Blue Tooth/Wi-Fi. Ansoft software HFSS is used in this research to make the antenna performance better and the operating principle of the proposed antenna is described in detail. Result of simulation reveals that the maximum gains of these four wide bands are 2.20,-0.99, 4.01 and 4.05 dBi, respectively. Moreover, this research also tests the return loss(S11) of the fabricated antenna with the vector network analyzer and the result is in accordance with the simulation result on the whole. There are four wide resonant frequencies which cover nine-band of wireless wide area network(WWAN), wireless local area network(WLAN) and long term evolution(LTE), when the available bandwidth is better than 6 d Bi return loss.     

铁道车辆天线梁的随机振动疲劳评估

引发天线梁破坏的主要原因是受到经构架端部传递的随机振动激扰.为考察天线梁在随机激扰下的疲劳可靠性,首先将结构动力学、随机振动和材料疲劳理论进行结合,研究了随机振动疲劳分析方法,在此基础上,依据标准IEC 61373,采用有限元软件ANSYS Workbench对天线梁进行随机振动仿真,最后采用Steinberg法对其应力较严重部位进行疲劳损伤评估.经分析,得到天线梁的总体损伤为0.56,满足Miner线性累计损伤准则,表明天线梁的疲劳设计符合标准的相关要求.     

最小二乘配点法分析微带天线问题

本文利用加权余量法中的最小二乘配点法分析了任意形状的微带天线, 文中以圆形天线为例进行了数值计算,所得结果与实验结果十分吻合。