一种等边三角形缝隙环宽带天线的设计

提出一种带有枝节槽的等边三角形缝隙环结构宽带天线.基于多模谐振原理,将天线馈源设置在三角形缝隙环中非对称位置,同时在三角形缝隙环上对称添加2个枝节槽以便形成更多谐振回路,从而激励出多个模式,得到多模谐振,提高缝隙天线带宽.仿真和实测结果基本一致.实测所设计的天线的阻抗带宽为2.11～3.32 GHz,|S11|<-10...     

小型化双枝节加载级联宽带滤波器设计

为在高频率选择性和大带宽的前提下实现小型化,提出一种紧凑非对称双枝节加载的易级联多模谐振滤波器.采用微波网络级联方法,分析优化设计了中心频率为6 GHz的单级、两级和三级多模谐振宽带滤波器.测试结果表明,该滤波器在5.41 mm×7.61 mm(0.21λg×0.29λg)有效尺寸下,带外抑制优于40 dB,损耗小于2...     

新型超宽带带通滤波器

提出了一种新型的短接环形多模谐振器,适合于构成超宽带带通滤波器。利用该多模谐振器的前三个谐振模式构成滤波器的整个通带．并提出通过改变多模谐振器阻抗比来控制该带通滤波器的相对带宽的方法。该结构具有易于级联的特性。通过级联可明显改善阻带特性。给出了一个单元以及三个单元级联后的滤波器结构以及通过仿真和实验获得的性能参数,验证了所设计的新型超宽带带通滤波器的有效性。     

宽带介质覆层Fabry-Perot 谐振腔天线设计

结合传输线理论和史密斯圆图分析,文中提出了一种利用全介质部分反射覆层构造宽带Fabry鄄Perot 谐振腔天线的方法。所设计的覆层结构在工作频带内拥有正斜率的反射相频特性,可满足谐振腔天线的宽带谐振条件。运用该方法设计了工作于Ku 频段的宽带Fabry鄄Perot 谐振腔天线,通过仿真计算和样件加工测试验证了该方法的正确性和有效性。     

北斗多模卫星导航天线设计

设计了一种可以工作在GPS L1、GLONASS 和北斗频段的多模卫星导航天线。采用“叠层结构”和引入宽带的带状线90°电桥,实现了天线的多频段工作。该天线易于调节,可以应用于不同的载体,具有与后端射频模块良好的集成性。     

面向车载鲨鱼鳍的宽频MIMO天线设计

为了解决车载通信天线工作频带窄、尺寸大等缺点,文中提出了一款应用于车载鲨鱼鳍外壳的新型小型化、宽带MIMO天线。为了实现天线的宽带特性,充分利用了印制单极子天线易于引入多谐振的特点,首先通过合理的尺寸设计,将单极子天线谐振频率设计至工作频段中;然后,使用缝隙加载技术,增加天线谐振模式数量并改善天线阻抗匹配特性,拓宽了天线带宽并实现了天线的小型化。为了验证天线实际性能,将天线安装于鲨鱼鳍外壳中进行了测试。结果表明,该天线可以覆盖824～5 000 MHz的频段范围,驻波比均小于3,增益最低1.9 d Bi、最高6.2 d B,效率均高于49.5%、最高达89.2%。该天线可满足车载通信系统对天线的宽带化和小型化要求。     

基于特征模理论的缝隙宽带天线设计

基于特征模理论,设计了一种新型微带缝隙宽带天线.该天线设计中,首先分析了三种不同天线结构的特征模态,得到初步的天线结构;然后依据该结构的特征电流分布,将天线馈源设置在多个模态的特征电流相似区域,激励出所需的目标模式,得到多模谐振,从而提高缝隙天线带宽.天线由一个长矩形缝隙和对称地镶嵌于其两侧的圆形缝隙构成,其馈源设置在...     

神经网络模型在多模多馈天线设计中的应用

文章采用人工神经网络对多模多馈天线进行建模,并应用于多模多馈天线的分析与设计中。由于神经网络具有精度高,实时调用速度快等优点,因此文章建立的多模多馈天线神经网络设计方法具有准确、可靠、省时及其它辅助设计等优点。文中的仿真结果证明了该方法在多模多馈天线分析设计中的有效性。     

短波多模多馈天线的工程设计

本文介绍了短波多模多馈天线的原理,分析了实现多模多馈的馈电网络.针对实际工程的需要,设计出满足实际需求的实体天线.经工程测试,天线性能指标良好.     

共面波导馈电的小型化双通带滤波器

提出了一种采用共面波导馈电的小型多模双通带平面滤波器,该滤波器采用内部嵌套的多模谐振器缩小了电路尺寸,利用奇偶模分析方法和弱耦合激励的方式分析了该多模谐振器的谐振特性,并依此推导出其谐振频率与物理尺寸的相互关系。为了满足滤波器的馈电,端口耦合并实现小型化,引入了异面共面波导馈电结构。文中给出了四个谐振模式的分析以及两个通带中心频率和带宽的控制机理,实现了滤波电路的频率和带宽的独立控制。最终实现了中心频率为2.39GHz 和4.34GHz,相对带宽分别为8.8%和13.4%的双通带平面滤波器。该滤波器中心频率和带宽独立设计可控,而且谐振器尺寸大小仅为0.09λg ×0.09λg 。本文所设计的滤波器结构简单、尺寸小,通带间隔离度较高、易加工制作,具有较高实用价值。     

Active Integrated Antenna Design Using a Contact-Less, Proximity Coupled, Differentially Fed Technique

A novel contact-less, differential feeding technique suitable for integrated active antenna design is demonstrated. This technique utilizes an odd mode signal to generate fringing fields on either side of a microstrip gap under the antenna. This allows electromagnetic energy to be efficiently coupled from the transmission lines to the radiating antenna. In a balanced integrated antenna amplifier configuration, the proposed non-contact feeding method removes the need for any balun or power combining network. Hence in theory, a compact RF front-end design with lower losses can be realized. This feeding method has been successfully applied to the design of simple passive microstrip patch antennas and active integrated antennas (AIA). Simulated and measured results are also included to validate the proposed feeding concept and antenna designs. The performance of the proposed differential feeding technique on a simple microstrip patch antenna has been systematically studied. The study suggests that the proposed proximity method is broadband in nature, allowing antennas operating at different resonant frequencies to be swapped without the need to change the feed dimensions and without degrading the matching performance     

Broadband calculable dipole reference antennas

A broadband calculable standard dipole antenna has been developed, with an uncertainty in the antenna factor (AF) of better than ±0.15 dB at the resonant frequency, f_res, in the frequency range 30 to 500 MHz and ±0.2 dB in the range 600 MHz to 1 GHz. For broadband operation of the dipole resonant at 60 MHz the uncertainty is ±0.2 dB over a range 0.33 f_res to 1.83 f_res. These uncertainties have been validated by close agreement of the measured insertion loss between dipole antennas above a conducting ground plane, with the loss predicted by analytical and numerical methods. The AF measured by the two-antenna method also agrees with the calculated AF. The technique was applied to reference monopole antennas for which AF was determined to an uncertainty of ±0.2 dB over the frequency range 10-100 MHz. The key achievements are: the construction of a very large and flat ground plane, validation of numerical versus analytical calculations of impedance and effective length of resonant dipoles, excellent agreement between measurements and method-of-moments calculations of the coupling between resonant dipoles, good agreement over a broad bandwidth, careful design of antennas and supports, and precision measurements     

An Equivalent Circuit Model for Broadband Modified Rectangular Microstrip-Fed Monopole Antenna

A new, simple equivalent circuit model for designing a multi-mode/broadband modified rectangular microstrip-fed monopole antennas using stepped cut at four corners (SCFC) method has been presented in this paper. The SCFC method is a method in which the four corners at the edges of the patch are cut for the purpose of designing the microstrip-fed monopole antenna. The design procedure of a single mode to a broadband microstrip-fed monopole antenna is explained in order to help understand more about the proposed equivalent circuit model and SCFC method. The computer simulation technology (CST) microwave studio and advanced design system (ADS) software are used to design and simulate of the proposed microstrip-fed monopole antennas and their equivalent circuit model, respectively. The operating bandwidth of the broadband antenna with \(\hbox {S}_{11}< -10\) dB, covers the operating frequency range from 0.9 to 2.6 GHZ that it is suitable for GSM (0.9 GHz), WiFi (2.4 GHz) and LTE (2.6 GHz) applications. For the purpose of validating the simulated results, the antennas prototype has been fabricated and measured. The comparison of the measurement and simulation results shows that, there is a good agreement between them.     

A Circuit-Theoretic Approach to the Design of Quadruple-Mode Broadband Microstrip Patch Antennas

A novel method for the design of broadband patch antennas is described. The approach taken is to broadside couple two dual-mode patch antennas, resulting in a quad resonance antenna. The equivalent circuit of the antenna is similar to that of microwave filters, thus filter design techniques maybe employed to synthesize the antenna to obtain maximum return-loss bandwidth. This is the first time an increase in the bandwidth is achieved on a relatively thin substrate antenna as a result of coupling four resonant modes using two stacked circular microstrip patches. Electromagnetic simulation and measured results demonstrate bandwidth improvement of over four times that of a single-mode design.     

Analysis of higher order regular polygonal loop antennas

Higher order regular polygonal loop antennas are analyzed. The input impedance of higher order antennas varies gradually when the operating frequency or the order of polygon changes. This behavior of input impedance provides a wide range of input impedance and many resonant points to antenna designers. The higher order regular polygonal loop antenna generally possesses higher directivity but poorer broadband impedance property. As the operating frequency becomes higher its directivity increases remarkably and the broadband property becomes more prominent. To achieve the desired properties one may select one of the many design data sets with a trade-off between broadband property and directivity     

多模反射面天线理论与技术研究

在卫星星座跟踪、远距离微波能传输等需要构建大功率均匀场的领域,都需要具有平顶波束的高增益反射面天线.受多模和混合模喇叭天线的启发,文中创新性地在反射面天线设计中引入了多模的理念.首先提出了双模反射面的思路,即在标准抛物面天线的最大辐射方向上引入相位差为180°的反相模式场,由两种模式合成平顶波束.然后,将双模的理念推广...     

一种多频宽带多模馈源的设计

为满足工程需求、实现天线的多频收发共用性能,文中基于模式匹配法设计了一款新型的多频宽带 多模馈源。该馈源集S/ X/ Ka 频段于一体,其中X/ Ka 多频段馈源采用新型的X/ Ka 宽带多模喇叭及X/ Ka、Ka/ Ka 频段宽带分波器。与已有的常规馈源相比,该馈源在Ka 频段拓展了带宽,带宽达到57%,在天线应用中各频段辐射 效率也大幅提高。采用模式匹配法进行设计,大大缩短了设计时间并保证了设计精度。该多模馈源喇叭对加工精 度要求不高,易于制造,在Ka 频段有很大优势。目前该馈源已应用于工程中,各项性能指标均优良。     

基于缝隙效应的几种宽带微带天线的设计

利用缝隙对天线带宽的影响设计了四种宽带微带天线。主要研究了缝隙的形状和大小以及与馈电的距离对天线带宽的影响。首先,宽缝机构可以较大的展宽天线的频带,如果同时配合在贴片上适当的开缝,带宽将进一步展宽;其次,相同缝隙结构的嵌套可使天线同时谐振在很多的频率,从而增加带宽。设计表明这几种微带天线都具有宽带特性,尤其是前两种天线具有超宽带（UWB）的特性,后两种天线的带宽也达到了48％以上。     

基于多模谐振加载支节的小型化双通带滤波器设计

使用多模谐振的加载支节设计了一种小型化双频滤波器。多模谐振加载支节由三条开路支节并联组成,通过调整这三根支节的长度,其前两个谐振模式可调整到一个频段内,而后两个谐振模式可以设计到另外的频段上,从而实现高隔离度的小型化双频滤波器。仿真与实测结果验证了上述设计思路。     

Broadband Active Receiving Patch With Resistive Equalization

The active integrated antenna (AIA) concept has been applied to design a broadband receiver front-end. A design procedure for active broadband patch antennas based on resistive equalization is presented. The use of the AIA has allowed the design of efficient RF front-ends by increasing its effective gain, noise figure, and merit . In addition to improving the classical parameters, the resistive equalization technique allows enlarging the bandwidths of the active antenna parameters versus the corresponding ones in passive antennas. A receiving patch antenna (with one amplifying stage) with a measured noise figure lower than 0.6 dB in a bandwidth over 38% and an effective gain improvement of 13 dB over the corresponding passive antenna has been achieved. The -parameter has also been measured for both the active and passive antenna, resulting in a relative planar of 16 dB/K, with a ripple of 0.5 dB, over a 30% bandwidth for the active antenna versus a of 22 dB/K for a typical front-end with a passive antenna over 20% bandwidth.