一种新型圆极化贴片天线的研究

研究了圆极化微带贴片天线,通过在普通圆形贴片上开槽,提出了一种结构新颖的圆极化微带贴片天线.仿真以及实测结果表明,该天线具有较宽的3dB波瓣宽度(±50°)和良好的圆极化轴比性能,并且新型微带贴片天线的尺寸要远小于普通的圆形或圆环形贴片天线的尺寸.     

一种改进的圆极化三角形口径耦合贴片天线

提出并设计了一种改进的宽带圆极化三角形口径耦合微带贴片天线。该天线由L形微带线、三角形缝隙和三角形贴片组成。通过L形微带线形成圆极化,三角形缝隙和三角形贴片形成单向辐射,缝隙和贴片印刷在不同的介质基片上以提高天线增益并缩减口径尺寸,同时在三角形贴片上切去一个角改善天线的圆极化特性。用HFSS设计了一款L波段的口径耦合贴片天线。仿真结果表明,天线的阻抗带宽26.5%,圆极化带宽22.5%,平均增益7.7 d B。     

单点馈电高增益圆极化三角形微带贴片天线设计

提出了一种单点同轴线馈电小型化高增益圆极化三角形微带贴片天线的设计方法。通过在三角形贴片的中心开一个十字形槽获得圆极化及尺寸缩减,同时在接地板上开三个同尺寸三角形槽提高天线的增益,通过调节三角形槽的尺寸在保持圆极化的情况下准确调节天线的谐振频率。HFSS仿真数据表明,当天线工作于2.43 GHz时,阻抗带宽和圆极化带宽分别为120 MHz(4.9%),30 MHz(1.2%),增益为3.5 d B。与传统的小型化方形贴片天线相比,该天线具有更小的贴片面积和更宽的工作带宽。     

三频双圆极化北斗天线的设计

设计了一款新型的小型化多频段圆极化北斗天线。天线采用双层层叠结构设计,上层天线采用矩形贴片切角开缝的方法,实现北斗系统L频段的左圆极化;下层天线利用复合左右手传输线结构进行设计,通过在矩形贴片中间位置加入非对称十字和直角折线槽结构,同时在四角位置加入90o折线结构和金属过孔,实现北斗系统B1频段、S频段以及GPS L1频段的右圆极化。天线尺寸为39 mm×39 mm×6.8 mm。仿真结果表明该天线各项指标均满足北斗系统对天线性能的要求。     

小型双频圆极化微带天线

随着卫星组合导航技术的发展,可同时接收多个频段信号的卫星接收天线的设计得到了广泛重视。设计了一种双频圆极化微带天线,该天线能够工作在GPS的L1(1.575 GHz)频段和RNSS B3(1.268 GHz)频段。该天线双层贴片之间采用相同的介电常数,天线使用单个探针馈电。与常规的双频圆极化微带天线相比,该天线在两层贴片之间没有空气层,因此天线尺寸小,结构更加紧凑,便于加工。     

一种小型宽带宽波束圆极化微带天线设计

介绍了一种小型宽带宽波束圆极化微带天线设计。该天线采用双层短路贴片,通过旋转结构设计结合多点馈电技术,实现了微带天线的宽带宽波束圆极化辐射。仿真与测试结果表明：VSWR〈2的阻抗带宽为15.9%（1.45～1.7 GHz）,半功率波束宽度和3 dB轴比波束宽度在8.6%（1.45～1.58 GHz）的频带内均大于100°,天线尺寸仅为0.43λ×0.43λ×0.035λ。     

一种寄生阵列宽带圆极化天线的设计

该文设计了一款C波段单馈寄生阵列的宽带圆极化天线。此天线采用紧邻的双层F4B介质基板,通过在方形驱动贴片上开槽及采用寄生阵列的设计实现了圆极化。对天线结构的设计步骤进行说明,研究了各结构对天线阻抗带宽和轴比带宽的影响,并研究了寄生贴片切角长度和驱动贴片上的缝隙宽度对天线轴比和带宽的影响。对天线的圆极化方向图进行了仿真。仿真结果表明,在5.5 GHz时实现了右旋圆极化,最大增益为8.1 dBi。加工并测试了宽带圆极化天线,测试结果与仿真结果基本相符,天线实测的阻抗带宽为1.3 GHz,轴比带宽为1.26 GHz。设计的叠层天线具有结构紧凑,装配简单和轴比带宽大的优点。     

一种新型V型槽圆极化微带贴片天线

提出了一种基于非对称V型槽加载的探针馈电圆极化单层钻石形微带贴片天线。通过调节V型槽的槽宽、槽长、开槽倾角及馈电点位置可实现微带贴片天线的圆极化辐射。研究了V型槽尺寸对微带贴片天线性能的影响。结果表明:介质厚度为0.051λ_0(λ_0为中心工作波长)时,天线的阻抗带宽大于9%(VSWR≤2),圆极化带宽为3%(AR≤3),最大增益可达6.29 d Bi,最小轴比小于0.5 d B。     

小型化缝隙加载圆极化及宽带微带贴片天线设计

提出了一种十字形缝隙加载的小型宽带及圆极化微带贴片天线的设计方法。该天线通过在方形贴片上加载一个大尺寸的十字形缝隙实现天线的尺寸缩减,介质基片采用由FR4和空气层组成的层叠结构,在缝隙中嵌入L型枝节,只需通过调整枝节上同轴线馈电点的位置来获得圆极化或宽带阻抗匹配。ANSYS HFSS仿真分析表明,天线的圆极化带宽（AR≤3 dB）为1.7%,阻抗带宽（VSWR≤2）为5.8%,天线在宽带范围内具有稳定的增益,峰值增益为7.8 dB,同时贴片面积缩减了52.3%。改变馈电点的位置可调节两个谐振频率使天线阻抗带宽达到9.4%,比传统的微带贴片天线阻抗带宽提高了114%。     

单馈点宽带圆极化微带天线设计

设计了一种单点馈电的宽带圆极化微带天线。针对微带天线带宽窄的问题,采用双层矩形贴片的层叠结构,通过辐射贴片之间的谐振耦合使天线的频带展宽,得到了良好的效果。在保证天线增益性能的基础上,增加了天线圆极化带宽。采用商用仿真软件HFSS对天线结构尺寸进行了优化设计,仿真结果显示,该天线工作于L波段时,VSWR<2的阻抗带宽达到10%,轴比特性良好,且在整个带宽范围内,天线增益和辐射方向图保持良好的一致性。     

Compact circularly-polarised circular microstrip antenna withcross-slot and peripheral cuts

Novel compact circular-polarisation (CP) operation of a circular microstrip antenna, with a cross-slot in the patch centre and a pair of peripheral cuts at opposite sides of the patch boundary, is proposed and experimentally studied. For operation at a fixed frequency, the proposed antenna using a single probe feed, can have an antenna size reduction of ~20% as compared to regular size CP operation of a circular microstrip antenna. Details of the experimental results are presented and analysed     

Circularly polarised microstrip antenna array using proximitycoupled feed

A 2×2 circularly polarised (CP) microstrip antenna array using a proximity coupled feed and sequential rotation is described. As compared with a previously presented single-element circularly polarised microstrip antenna with a cross-slot, the new array achieves a much wider impedance bandwidth of 11.18% and has an axial ratio bandwidth of 4.1%. The return loss, radiation patterns and axial ratio of the antenna array were measured and are presented     

Adjustable axial ratio of single-layer circularly polarised patch antenna for portable RFID reader

A novel single-layer, proximity-fed technique for a slot-coupled circularly polarised square patch antenna operated in the ultra-high frequency band is presented. In the proposed design a pair of radiating square patches with a cross-slot and a microstrip feed line are both etched on the top of a microwave substrate, and a coupling arrowshaped slot is etched on the bottom of this substrate. Simulated and measured results indicate that the proposed structure can achieve circular polarisation operation. Proper adjustment of the feed coupling gap distance between the patch and the feed line results in good impedance matching and circularly polarised radiation, and an impedance bandwidth (VSWR <= 2) of about 3.74% and a 3 dB axial-ratio bandwidth of about 1.62% were obtained.     

Small slot-coupled circularly-polarised microstrip antenna withmodified cross-slot and bent tuning-stub

A novel design of small slot-coupled circularly-polarised circular microstrip antenna with a modified cross-slot cut in the patch and a bent tuning-stub aligned along the patch boundary is proposed and experimentally studied. Results show that, for fixed circular polarisation (CP) operation, the antenna proposed can have an antenna size reduction of ~80%, as compared to a regular-size CP design. The significant size reduction of the proposed antenna is due to the novel modified cross-slot cut in the patch, and CP operation is obtained using a bent tuning-stub incorporating a properly oriented coupling-slot in the ground plane of the microstrip feed line     

Inclined-slot-coupled compact dual-frequency microstrip antennawith cross-slot

A design using an inclined-slot-coupling feed for dual-frequency operation of a rectangular microstrip antenna with a cross-slot is described. Results show that, for a given dual-frequency operation, a reduction in antenna size of ~40% can be achieved by using this design. Also, the frequency ratio of the two frequencies is very slightly affected by the cross-slot length, and mainly determined by the aspect ratio of the patch, making the design simpler and easier to implement     

宽带圆极化微带天线的几种实现方法

在简要概述圆极化微带天线工作原理的基础上,重点介绍了目前国内外较为先进的圆极化微带天线实现宽带的多种方法,包括微带贴片天线、缝隙天线,以及采用PBG结构的圆极化天线。这些方法分别采用单点馈电,多点馈电或多元组合实现圆极化,均有效拓展了圆极化天线的阻抗匹配带宽和圆极化轴比带宽。参考一些实例验证了这些方法的可行性,然后展望了其可能的发展趋势。     

单层贴片圆极化天线的小型化研究

本文介绍了微带天线的小型化的发展和圆极化天线的特性。在微带天线腔模理论的基础上,通过附加缝隙微扰单元 实现单馈点的单层贴片的圆极化天线,并在此基础上,采用在天线表面开槽嵌缝的手段,设计出一款小型化的圆极化天线。 通过仿真实验,对比两种天线的结果,可以看出本文设计的两款天线均能满足圆极化性能的要求,而经过嵌缝的天线实现了 天线小型化的目的。     

Circularly polarised aperture coupled microstrip antenna

The orthogonal mode of an aperture coupled rectangular microstrip antenna can be coupled to the aperture-excited mode with coplanar microstrip lines to provide a compact circularly polarised element with a single aperture feed. An equivalent circuit model was developed for the analysis and design of this element, and a working version was used to demonstrate the concept. The features of this antenna are compared with several other circularly polarised microstrip antennas     

Circularly polarised patch antenna array using proximity-coupledL-strip line feed

A microstrip antenna array for circular polarisation (CP) using a proximity L-strip line feed is proposed and experimentally investigated. By placing a cross-slot with unequal slot lengths on the circular patch, circular polarisation can be excited. Also, a sequential rotation technique is adopted for the design of this CP antenna array to widen the bandwidth. The impedance and axial ratio bandwidth values are 78 and 16.15%, respectively. The boresight axial ratio is 0.4 dB at 1.91 GHz     

Design of wideband circularly polarized aperture-coupled microstripantennas

Two variations of a novel feeding technique for a wideband circularly polarized aperture-coupled microstrip antenna are described. Prototype designs for wideband linearly polarized elements are first presented, and then used for circularly polarized designs. Techniques used for design of the feed network are detailed, for both series feed and parallel feed versions. Experimental results are shown for each antenna, and results for the two designs are compared. The impedance and axial ratio bandwidths for these antennas are among the best yet achieved for microstrip antenna elements. Several design variations are also discussed