一种新型宽带圆极化介质谐振器天线设计与实现*

设计了一种宽带圆极化介质谐振器天线,为一种鼠笼形的宽带一分四90毅相移功分微带馈电网络,采用缝隙耦合对介质谐振器顺序旋转耦合馈电。天线结构紧凑、加工简单,仿真和实测结果吻合良好,其阻抗带宽和低于3dB的轴比带宽重叠部分在1.09 GHz-1.83GHz、为50.7%。增益大于3dB 及轴比小于3dB 的波束宽度均达到90°。天线工作频率覆盖四大导航系统,包括中国的北斗系统、美国的GPS 系统、欧洲的伽利略(GALTLEO)系统和俄罗斯的格洛纳斯(GLONASS )系统的频段,天线可应用于全球卫星导航定位系统和无线宽带通信系统中。     

一种低剖面宽带二维宽角扫描圆极化阵列天线

针对现有圆极化平面阵列的扫描角受限和三维宽角扫描阵列体积大的问题,设计了一种基于阵因子方向图和单元因子方向图互补的低剖面宽角扫描圆极化阵列天线.该阵列单元采用新型圆极化正交偶极子天线,并由其组成多个圆环子阵,每一子阵内单元的法向均偏离阵列法向一个固定倾角并等间距排布在"涟漪"状金属地板上.这种阵列排布方式使得在主波束扫描至大角度时天线单元因子增益可以补偿阵因子的增益下降.设计的一个64元阵列天线的实测结果表明:在8~9 GHz工作带宽内,且波束扫描覆盖0°~±62°,各阵元的有源驻波比均小于2.1,中心频点扫描增益起伏小于1.71 dB,扫描波束的圆极化轴比小于2 dB.     

基于零阶谐振器的低剖面宽带锥状波束微带天线研究

提出一种利用零阶谐振器实现锥状波束天线带宽展宽的新技术。天线将4个零阶谐振器加载到圆形贴片内,从而引进新的谐振,大大增加天线的带宽。该技术将天线的带宽从4.86%扩展到12.8%。天线增益达到5 dBi,最大辐射方向为36°。该天线具有结构简单、加工容易、剖面低和成本低的优点,在整个频段内具有良好的锥状波束特性,而且波束稳定性良好。     

介质谐振天线的发展

介绍了介质谐振器及其特点，并详细地分析了当前已有的各种介质谐振天线和新型介质谐振天线。     

一种低剖面宽带宽角扫描阵列天线的设计

基于超材料技术理念,在考虑阵元间互耦效应下,优化设计了一种低剖面宽带宽角扫描阵列天线,使该阵列剖面为最低工作频率的四分之一波长,相对带宽达55%下,工作频段内中心阵元的平均工作效率高达87%以上,30o扫描角范围内的平均有源驻波系数小于2.0,其阵元方向图E面、H面的半功率波瓣宽度大于60o。研制的6伊8阵列样机测试结果说明了阵列天线具有良好的宽带宽角扫描特性,同时该天线具有结构紧凑、重量轻和易于实现的特点,在相控阵雷达天线中有很大的应用价值。     

圆极化倾斜波束介质谐振天线设计

基于非对称结构设计思想,以表面倾斜的高介电常数介质谐振器为辐射单元,采用改进的正交不等长缝隙结构耦合馈电,设计制作了一种圆极化倾斜波束介质谐振天线。通过对介质谐振器表面倾斜角度和馈电缝隙的参数优化,扩展了天线的频带宽度,实现了宽频带圆极化倾斜波束辐射。仿真结果表明:天线在同时满足S11<-10 d B、3 d B轴比和30°波束倾斜条件下的带宽为18.2%。同时,由于采用高介电常数介质谐振器,天线剖面高度降低到0.165λ。实测结果和仿真结果吻合较好,验证了该设计的有效性。     

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。     

基于超表面的宽带低剖面圆极化天线设计

设计并制备了一种基于超表面的宽带低剖面圆极化天线。该天线由上下两层构成,下层是传统的线极化缝隙微带天线,上层是由方形切角单元构成的超表面。分析了超表面将线极化波转换成圆极化波的工作原理,并对影响天线圆极化带宽的参数进行了优化。仿真结果表明:加载超表面后,不仅使天线辐射圆极化波,还扩展了天线的阻抗带宽,天线相对阻抗带宽达到17%,3 dB轴比带宽达到7.2%。为了验证设计的有效性,加工、测试了天线实物样品,并与仿真结果进行了对比。实测结果与仿真结果吻合较好,说明该天线具备宽带圆极化特性。最终天线整体尺寸仅为0.4λ×0.4λ×0.03λ,天线的剖面较低,非常有利于与载体共形的应用。     

一种低剖面的宽带双极化超表面天线

提出了一种低剖面的宽带双极化超表面天线。天线由正交微带线馈电,通过方形驱动贴片激励上层超表面层。该超表面由4×4的方形贴片构成。当垂直/水平极化端口激励时,超表面天线工作在TM₁₀/TM₀₁和反向TM₂₀/TM₀₂模。为了拓展天线的带宽,在超表面上额外刻蚀了4条较宽的缝隙,并在驱动贴片两侧加载了2个寄生条带。此外,将微带线略偏移馈电边的中心,以提高天线的隔离度。天线剖面仅为0.065λ₀(λ₀为中心频率在真空中的波长)。加工和测试了天线样品,测试结果表明,天线的反射系数|S₁₁|<-10 dB带宽为43.8%(8.76～13.74 GHz),带内隔离度大于16.8 dB,增益在5.5～9.2 dBi范围,交叉极化为-14.4 dB。考虑加工误差后,仿真结果与测试值较为吻合。     

低剖面宽带圆极化天线阵列

基于双馈双线极化微带天线,结合威尔金森功分器、T形结功分器及顺序旋转馈电的优点,设计了一种新型低剖面宽带圆极化2×2天线阵列。把辐射贴片和馈电网络集成在同一介质层,有效地利用了介质空间,降低了天线的剖面,增加了天线的带宽。4个天线单元顺序旋转90°,利用一分四T形结功分器给4个单元等幅、相位依次相差90°馈电。根据Ansoft''s HFSS仿真结果,制作了样机。样机实测结果和仿真结果吻合。实测结果表明,该天线阵驻波带宽可以达到27.78%,3-dB轴比带宽可以达到52%,最大增益为14.19 dB。     

Cross-T-shaped dielectric resonator antenna for wideband applications

A new dielectric resonator antenna (DRA) is introduced for wideband applications, where the wideband of this DRA design comes from three factors: a compact cross-T-shaped dielectric resonator, a conformal inverted-trapezoid patch as a feed mechanism, and a copper-clad substrate as a baseboard. Measured results demonstrate that the proposed DRA achieves an impedance bandwidth of about 71.8% for VSWR les 2, covering a frequency range from 3.56 to 7.57 GHz. This antenna also provides a stable broadside radiation pattern and a gain range of 3.2-7.3 dBi across the operating bandwidth.     

Experimental investigation for wideband perforated dielectric resonator antenna

A wideband perforated dielectric resonator antenna (PDRA) is presented. The effective permittivity of the dielectric resonator is altered by drilling holes into a circular ring lattice inside the DRA. The PDRA is equivalent of having an annular ring with lower permittivity outside the cylindrical disk, resulting in enhanced impedance bandwidth. The measured bandwidth of a prototype PDRA with relative permittivity 10.2 is 26.7% (S/sub 11/<-10 dB).     

Ultra wideband monopole/dielectric resonator antenna

A hybrid antenna is presented, consisting of an annular dielectric resonator antenna combined with a quarter-wave monopole to simultaneously act as a radiator and a loading element, producing an ultra wideband response. A prototype antenna is designed and a 3:1 bandwidth is demonstrated.     

Compact dielectric resonator antenna for WLAN applications

A new dielectric resonator antenna (DRA) with reduced size for WLAN applications is presented. The proposed antenna consists of a rectangular dielectric resonator with partial vertical and horizontal metallisations which is coupled to a microstrip line through a rectangular aperture in the ground plane. A 9.6 reduction coefficient is obtained compared to the volume of an equivalent isolated DRA. An experimental 12% bandwidth is also achieved in spite of the compact size.     

Rectangular dielectric resonator antenna for ultrawideband applications

A new dielectric resonator antenna (DRA) is introduced for ultrawideband applications. A rectangular dielectric resonator, a bevel feeding patch and an airgap between the DR and ground plane are used to obtain an ultrawideband impedance bandwidth. The effective dielectric constant and the Q-factor can be reduced by using the airgap and the bevel-shaped feeding mechanism, which can provide a smooth transition from one resonant mode to another. Measured results demonstrate that the proposed DRA has a wide bandwidth from 2.6 to 11 GHz with VSWR less than two, covering the frequency range of more than 120%. Experimental and numerical results are carried out and discussed, showing good agreement.     

A wideband high gain dielectric resonator antenna for RF energy harvesting application

A novel high gain and broadband hybrid dielectric resonator antenna (DRA) is designed and experimentally validated. To obtain the wide impedance bandwidth, the proposed antenna geometry combines the dielectric resonator antenna and an underlying slot with a narrow rectangular notch, which effectively broadens the impedance bandwidth by merging the resonances of the slot and DRA. An inverted T-shaped feed line is used to excite both antennas, simultaneously. It supports amalgamation of different resonant modes of the both, DRA and slot antenna. The measured results show that the proposed antenna offers an impedance bandwidth of 120% from 1.67 to 6.7 GHz. The antenna gain is next enhanced by a reflector placed below the antenna at an optimum distance. On engineering the height and dimension of this reflector the antenna gain is improved from 2.2 dBi to 8.7 dBi at 1.7 GHz. Finally, antenna operation is attested experimentally with a rectifier circuit in the frequency range of 1.8–3.6 GHz, where various strong radio signals are freely available for RF energy harvesting. The measured maximum efficiency of the rectifier and rectenna circuit were found to be 74.4% and 61.4%, respectively.     

一种基于超表面的低剖面宽带透镜天线

提出一种新型的基于超表面的低剖面宽带高增益透镜天线,该透镜采用宽带的电偶极子天线作为馈源,设计中心频率工作在10 GHz.针对超表面透镜在不同位置的折射率的需求,同时提出了一种新型的非谐振超材料单元,该单元由三层介质板组成,中间一层是印有十字形带状线的双层印刷板.通过改变上下两层介质的介电常数,可以达到不同的折射率变化范围,从而实现透镜的中间层和阻抗匹配层对折射率的需求.所提出的透镜天线设计方法可以获得21 dBi的最高增益以及58%的-10 dB阻抗带宽.更重要的是所提出的具有高折射率的超材料单元可以实现只有0.32λ₀的透镜厚度,大大减小了透镜的剖面.最后进行了加工实验,对所提出的方法和仿真结果进行了验证,实验结果表明,透镜天线的实测带宽、方向图和增益都与仿真理论结果有较好的吻合度.     

加载多层介质谐振器的宽带背腔缝隙天线设计

提出并设计了一种工作于X波段的新型宽带背腔缝隙天线,通过在缝隙外侧加载多层介质谐振器,有效扩展了天线带宽并显著提高了天线增益.设计的天线中心频率为10 GHz,-10 dB回波损耗带宽约为40％;带内增益5～9.5 dBi,比未加载多层介质谐振器的背腔缝隙天线提高2～3 dB.实测结果同设计结果基本吻合,有效验证了该设计的正确性.     

超宽频单极子陶瓷介质谐振器天线设计与仿真

设计了一种尺寸小、频带宽、结构简单的单板子陶瓷介质谐振器天线,该天线经由在单板子周围加一个环形的介质谐振器而成.该设计主要通过在环形谐振器中使用高介电常数的陶瓷材料降低天线的尺寸,利用环形谐振器与单板子谐振频率之间的耦合展宽天线的频带.利用仿真软件HFSS为该天线建立模型并进行优化仿真,得到了最佳的天线设计参数,优化所...     

120 GHz on-chip multi-mode wideband dielectric resonator antennas for THz applications

This work discusses the design methods of 120 GHz on-chip dual-mode and three-mode dielectric resonator antennas (DRAs) based on a standard CMOS technology. The bandwidths of the DRAs are expanded by merging adjacent modes with similar radiation patterns. The impedance bandwidth of 18.6% with the peak gain of 6 dBi is achieved for the proposed on-chip dual-mode DRA. In addition, the impedance bandwidth of 20.1% with the peak gain of 6.9 dBi is achieved for the proposed three-mode DRA. To the best of authors’ knowledge, the on-chip multi-mode DRAs are first proposed. The impedance bandwidth of the proposed three-mode on-chip DRA is wider than the other on-chip DRAs using planar feeding with on-chip ground. The proposed antennas are promising for terahertz applications due to the merits of wide band, high gain and high radiation efficiency.