一种新型宽波束圆极化微带天线的设计

设计了一种新型宽波束圆极化微带天线,该天线采用四探针馈电,馈电网络由威尔金森功分器和传输线移相器组成,使四个馈电探针的相位依次相差π/2,实现了右旋圆极化辐射。通过Ansoft HFSS仿真结果表明：该微带天线结构简单、极化纯度高、全向性能好、轴比小于3dB的圆极化带宽达到27.7%,高于一般的微带圆极化天线（轴比小于3dB带宽约为15%）。天线可以很好地满足GPS通信的技术要求,也可用于无线局域网。     

左/右旋圆极化可重构微带天线

设计了一种左/右旋圆极化可重构的微带天线。在矩形微带贴片的两条边上增加枝节,贴片与枝节通过PIN 二极管开关连接,通过控制PIN 二极管的通断来改变正交模式的相位差,使天线在同一个馈电点上可实现左旋圆极化（LHCP）和右旋圆极化（RHCP）的重构。该天线在（2800±10）MHz 的频率范围内驻波比小于2,轴比小于3dB。仿真结果与测试结果均验证了该方案的可行性。     

新型小型化圆极化微带天线

本文介绍一种新颖的单馈点圆极化矩形微带天线，它利用新型磁性材料基片和开槽设计实现了小型化。文中基于时域有限差分法分析，给出了矩形贴片中心槽和边槽不同尺寸对天线输入阻抗和反射系数的影响，并得出其设计原则，同时给出了实验天线的测试结果。实验天线的圆极化轴比带宽（小于3dB)约为3.5%，而阻抗带宽（驻波比小于2）达12.6%，约为常规设计的5.5倍，而其尺寸比常规矩形微带天线减小了40％以上。可见这种设计可以满足一些实际应用（如GPS天线）的需要。     

一种新型共口径双频圆极化微带天线

设计了一种单探针馈电的共口径双频圆极化微带天线。该天线采用圆形缺口贴片形成圆极化模,并通过在其内侧开特定形状的环形槽,构造了另一个较小尺寸的圆形缺口贴片,从而形成了分别对应主模和高次模的双辐射模型,获得双频圆极化特性。对天线进行了优化设计和实物加工,测试结果表明,该天线在1280±10MHz和2280±20MHz两个频段上均获得了驻波比（VSWR）小于2和轴比（AR）小于3dB的良好的阻抗匹配和圆极化特性。     

一种新型低剖面宽带微带开槽天线的设计

针对低剖面微带天线,提出一种新型的带宽展宽方法。通过在低剖面E-形微带天线中引入分布式LC谐振电路,使得该分布式LC电路产生的谐振点与低剖面E-形微带天线的固有谐振点相互靠近,从而有效地拓宽了天线的带宽。基于该设计思想,设计出工作于AMPS频段(824～894MHz)的低剖面微带天线,该天线的空气层厚度仅为0.0344λ0,远小于国内外文献报道的同类天线。测量结果表明:设计出的低剖面微带天线工作带宽达到9%(VSWR2),而且在该阻抗带宽内具有良好的辐射特性。该设计思想同样适用于其他形式的低剖面开槽微带天线设计。     

超表面加载极化可重构双极化微带天线设计

基于超表面结构设计了一种2.555~2.655 GHz频段的极化可重构双极化微带天线。首先根据微带天线理论设计了缝隙耦合正交馈电的双极化微带贴片天线,然后提出并设计了一种方形切角的新型超表面结构,并将该超表面放置在双极化微带天线上,通过机械方式旋转超表面,实现了左、右旋圆极化和水平、垂直线极化之间的极化转换。利用HFSS仿真软件对该超表面加载微带双极化天线进行了仿真。结果表明,该双极化天线能够便捷地实现极化转换,且在两种极化状态下,天线在工作频带内的回波损耗小于–10 dB,隔离度大于20 dB,圆极化工作状态下的轴比小于3 dB,天线的整体性能良好。     

单频圆形微带贴片天线设计

基于微带贴片天线在无线引信中的应用,设计了一种中心频率为7.2 GHz的同轴馈电圆形微带天线,该天线介质基片相对介电常数为εr=4.4,回波损耗小于-20 d B,天线增益大于5 d B。根据微带天线原理,通过HFSS软件设计的天线,实验结果表明:天线谐振频率、回波损耗等性能参数符合设计要求。     

声表面波射频识别系统的阅读器微带天线设计

基于微带天线的基本理论,设计了一种适合用作声表面波射频识别系统的阅读器天线。首先,计算分析了该微带天线的基本尺寸,并利用ADS软件设计了有阻抗变换器功能的微带线,使天线输入阻抗达到50Ω;然后,利用HFSS软件进行了微带天线的建模仿真和参数优化,确定了天线的最终尺寸;实际制作天线并对其进行了测试,测试结果和仿真数据吻合较好,在谐振频率处驻波比小于2;最后,结合阅读器对标签进行了无线测试,验证了阅读器天线的可用性。     

基于光子晶体的小型微带天线的分析与设计

针对传统微带天线低频端尺寸较大的缺点,设计了一种基于光子晶体的新型微带天线结构,即通过采用在传统微带天线贴片下方挖出凹槽,将辐射板放入凹槽中,并在微带天线的介质基板中引入高度不同的周期性圆柱空气隙光子带隙（PBG）结构的设计方案。采用基于有限元方法的电磁仿真软件HFSS 10．0对所设计的天线进行了仿真。仿真结果表明,当回波损耗小于-10．0dB时,天线的工作频段分别为2．40GHz～2．51GHz和3．54GHz～3．62GHz,且天线在这两个频段内具有良好的辐射特性。与传统的微带天线相比,所设计的天线后向辐射明显降低,且其整体尺寸减少了59．19％,从而验证了这种设计方案的有效性。     

一种小型陷波多用途超宽带天线

提出了一种小型陷波多用途超宽带微带天线。该天线与一般的宽缝隙微带天线类似,通过在矩形调谐支节上开V形缝隙获得了陷波特性。通过数值仿真和实验测量,对天线的阻抗特性、方向图和增益进行了研究。结果显示该天线在2.4到11GHz频段内驻波比小于2,在5.15~5.95 GHz范围内具有陷波特性。同时该天线还可覆盖2.4GHz无线局域网(WLAN)频段,在整个工作频段内有良好的辐射方向特性。     

一种十字形缝隙耦合的Ku波段宽频带双极化微带天线

采用十字缝隙耦合,层叠贴片和微带线馈电的结构形式,设计了一种适用于Ku波段的宽频带双极化微带天线。利用电磁仿真软件CST 5.0微波工作室对天线的电特性进行仿真优化,并制作了实物模型,实测结果和仿真结果吻合良好。两馈电端口回波损耗小于-10 dB的阻抗带宽分别达到34.2%和28.7%,端口隔离度高于21.4 dB。     

Low profile wideband antenna with shaped beams for indoor DVB-H applications

A novel low profile wideband antenna for digital video broadcastinghandheld (DVB-H) indoor applications is presented. The antenna can operate in two modes (circular patch antenna mode and microstrip mode), which leads to down-tilted beams when the antenna is mounted on a wall. An antenna prototype with a height of 46 mm has been constructed and tested. The simulated and measured results show that the antenna has VSWRs less than 2.0:1 and shaped radiation beams in the DVB-H band (470?706 MHz).     

双圆极化微带天线的设计

研究了小型化双圆极化微带天线的设计方法。重点讨论了实现双圆极化、宽波束宽度微带叠层天线小型化的实现方法,并利用仿真软件进行仿真分析,在此基础上研制了样件,对其电性能进行了测量,测量结果表明:此微带天线具有圆极化、宽波束宽度和小型化的特点。     

一种用于微带半波振子天线的新型BALUN

通过将常规的空气板线BALUN微带化，从而建立一种新型微带BALUN。该BALUN引入一个并联谐振电路，可以有效补偿半波振子的串联电抗而实现微带半波振子带宽的最大化。采用此种BALUN设计制作了一个L波段微带偶极子天线单元。测试结果表明：该半波振子天线在21．8％的带宽内驻波比优于1．18，带内交叉极化优于一21dB，接近理论最大设计带宽。     

Millimeter-wave proximity-coupled microstrip antenna on an extendedhemispherical dielectric lens

A low-cost, high-gain, millimeter-wave antenna is presented. The antenna is composed of a proximity-coupled microstrip patch mounted on the back surface of a substrate lens. The antenna utilizes low dielectric constant, low-cost materials and is therefore suitable to many commercial millimeter-wave systems. A full-wave analysis was developed to analyze the performance of the printed antenna and a prototype was developed for operation at 38 GHz. The impedance bandwidth of the prototype was 8% and the gain was approximately 30 dBi across this frequency span with a front-to-back ratio greater than 60 dB     

Broadband circularly-polarised microstrip antenna with switchable polarisation sense

A circularly-polarised microstrip antenna capable of switching polarisation sense is presented. The proposed microstrip antenna has a circular radiating patch and is excited by an open-loop microstrip line through the coupling of a ring slot in the ground plane. Two ends of the open-loop microstrip line can be taken for the input ports to excite right-hand and left-hand circular polarisations, respectively. A prototype using PIN diodes to electrically switch the input ports is implemented, and the measured results show the 3 dB axial ratio bandwidth of more than 10% can be obtained at the two polarisation senses     

Broad-band dual-polarized single microstrip patch antenna with highisolation and low cross polarization

This paper presents a new design of a broad-band dual-polarized single microstrip patch antenna with highly decoupled input ports and low cross-polarization (XP) radiation. A prototype of the proposed antenna with center frequency at 1800 MHz is presented. Both the dual linear polarizations have 10-dB return-loss impedance bandwidths greater than 14% and high decoupling between the two input ports (S₂₁ less than -40 dB across the entire bandwidths) is obtained. Moreover, the XP radiation in the principal planes of the dual linear polarizations is seen to be less than -20 dB     

一种结构新型的双频双极化共口径微带天线

介绍了一种结构新型的双频双极化共口径缝隙耦合微带天线,天线工作的中心频率分别为2.1GHz(L波段)和8.6GHz(X波段),在两个工作频率采用了底馈的馈电方式.用时域有限差分法分别对L波段和X波段双极化的微带辐射单元进行了模拟分析,制作了L波段的2×2元即X波段的8×8元阵天线,同时给出了测量结果.     

Slot-coupled microstrip antenna for broadband circular polarisation

A microstrip antenna with broadband circular polarisation (CP) is presented. The proposed microstrip antenna has a circular patch and is excited by a series microstrip-line-feed configuration through the coupling of a ring slot in the ground plane. The broadband operation is achieved by coupling two CP resonant elements, which are due to the circular patch and the ring slot, respectively. A typical prototype using foam material of thickness 5 mm as the antenna substrate is constructed. Measured results show the 3 dB-axial-ratio bandwidth centred at 2500 MHz is more than 10%.     

Compact microstrip-line-fed ring monopole antenna with tuning strip for 5 GHz WLAN operation

A novel compact and simple microstrip monopole antenna for 5 GHz wireless local area network (WLAN) operation is proposed. To excite a resonant mode in the operating band, a tuning strip is added to the antenna, which consists of a rectangular ring microstrip and a top loaded vertical strip, and is fed by a 50 /spl Omega/ microstrip line. The effects of the added strip to the impedance matching have been studied. A constructed prototype of the proposed antenna has been tested and bandwidth of about 930 MHz ranging from 5.03 to 5.96 GHz, monopole-like radiation pattern, and average gain of greater than 2.6 dBi over the operating band have been obtained.