一种新型的超宽带锥削缝隙天线设计

提出了一种微带线-槽线馈电形式的指数锥削缝隙天线,在辐射臂的外边缘引入半椭圆形缝隙来进一步提高天线低频段的定向性,获得了高增益和超宽带性能。利用HFSS12软件进行仿真,天线的极化方式为垂直极化,在2~13 GHz的工作频段内电压驻波比＜2,增益最高达11 dB,具备良好的定向性,仿真与实测结果基本吻合,表明该设计是有效、可行的。     

基于圆波导缝隙的双极化水平全向阵列天线设计

设计了一种具有水平全向辐射特性的双线极化圆波导缝隙阵列天线。利用双模式转换器馈电，以提供天线所需的TM₀₁及TE₀₁模式，并抑制波导内其余高次模和基模的传输；通过沿圆波导周向交错排列的矩形横缝及纵缝，分别实现垂直和水平极化；其中将横向矩形缝隙设计为平行双环结构来增加带内谐振点，进而拓展天线的工作带宽；此外，将两种缝隙沿波导轴向进行组阵，并在天线阵列末端设计了匹配结构用以减小TM₀₁模式所带来的能量反射。仿真结果表明：该天线两种极化方式电压驻波比小于2的驻波带宽为2.75 GHz～2.95 GHz,并且整个工作频段内，两种极化方式下的增益均超过7.5 dB,水平面内不圆度小于1.8 dB,可适用于气象雷达领域。     

基于电阻和槽加载的小型化超宽带Vivaldi天线

设计了一种小型化超宽带Vivaldi天线.该Vivaldi天线采用共面结构,以降低交叉极化电平.为了向低频拓展天线的工作带宽,实现小型化设计,首先在传统的微带线转槽线的巴伦基础上加载电阻;其次,在辐射臂上加载7对不同长度的槽.整个天线的尺寸为0.32λL×0.24λL(高×宽,λL为最低工作频率波长).仿真和测试结果都说明该天线的工作带宽为fL～12fL,增益在0dBi ～ 10dBi.该天线可以应用于对尺寸和带宽有严格要求的电子对抗领域.     

一种超宽带长槽阵列天线单元设计

针对地面对长槽阵列天线阻抗带宽的影响问题,设计出一种在激励偶极子上实施加载的超宽带长槽天线,其阻抗匹配带宽显著增加,最终得到了超过3. 5:1 的阻抗匹配带宽;在扫描范围内具有稳定辐射特性。该天线具有超带宽、剖面低、易共形等特点,在超宽带小型化相控阵天线中有良好应用前景。     

一种新型X波段超宽带介质谐振器天线的设计

设计了一种新型的超宽带介质谐振器天线。该天线采用微带-槽耦合馈电方式,通过在地板上开矩形槽,背面由50Ω的微带线中心馈电,从而展宽带宽。采用类似T型层叠结构,产生两种频率相近的模式,从而显著提高天线的阻抗带宽。仿真结果显示,该新型超宽带介质谐振器天线工作于X波段,天线的相对阻抗带宽达到47.37%,频段内平均增益超过7.2 d Bi,天线方向图对称性良好。天线的整体辐射特性良好,且结构简单,易于实现,可应用在微波通信、雷达等领域。     

一种小型的双极化共形天线设计

设计了一种小型的双极化共形天线,该天线由四个倒F 天线和一对差分微带线功分器组成,其中,四个倒F 天线等间距顺序排列在环形介质板上,相对位置上的倒F 天线通过差分馈电产生双线极化。采用电磁仿真软件Ansoft HFSS 17对该天线进行了设计和仿真,结果表明:该天线工作在495 MHz~505 MHz 频带内满足驻波比小于2,在工作带宽内实现了双线极化辐射特性,并且具有稳定的增益。天线主体尺寸为0. 25λ×0. 25λ×0. 11λ(λ 表示中心频率在自由空间中的波长),有效地实现了小型化。此外,文中提出的天线采用共形设计,天线附着在圆柱形腔体壁上,几乎不占用腔体内部空间,更容易集成到其他系统中,对于多天线系统的设计具有良好的参考价值。     

采用新型背腔的对数周期缝隙天线

针对超宽带雷达探测系统,提出了一款具有定向辐射性能的背腔式对数周期缝隙天线.该天线由一种具有超宽带匹配特性的渐变共面波导馈电.通过在缝隙天线背面设置谐振腔,使缝隙天线具有定向的辐射方向图.根据矩形谐振腔的特点,设计了一种新型结构的谐振腔,使得天线的驻波比(Voltage Standing Wave Ratio,VSWR)小于2.5.仿真与实测结果表明:天线在整个频带(0.9~5GHz)内具有稳定的定向辐射方向图,新型谐振腔和吸波材料的使用使天线最低工作频率可到0.9GHz,可使天线在整个频带内得到较高的天线增益.设计的天线适于应用在导航、探测以及超宽带(Ultra-wide Band,UWB)雷达等领域.     

具有双阻带特性的新型超宽带天线研究

通过在天线上开设不同形状和尺寸的槽,设计和制作了一种新型的采用微带馈电且具有双阻带特性的平面超宽带天线。通过HFSS对天线仿真并分析,总结出了槽结构参数对天线阻带特性的影响规律。仿真和实测结果表明,除阻带外,天线在3.015~13.27频带上的VSWR小于2,相对带宽达126%,在3.25~3.6GHz、5.15~5.825 GHz具有良好的阻带特性,较好地避免了系统与Wimax及WLAN之间的干扰。该设计天线在工作频段内具有很好的辐射方向性和增益,满足超宽带通信的需求。     

一种应用于平方公里中频阵的八角环天线阵

结合平方公里中频孔径阵列的应用场景,文中提出了一种基于电阻膜频率选择表面的超宽带八角环天线单元。其通过在八角环天线阵列与接地板之间加载方环形电阻膜频率选择表面,对由金属地板在对应频点因反相叠加而产生的驻波峰值有效抑制,进而拓宽了天线带宽以及降低了天线剖面。仿真结果表明:加载电阻膜频率选择表面后,天线阵元最终在±45°扫描范围内获得了5:1的阻抗匹配带宽,且天线的剖面降低了约27%。此外,在整个工作频带内天线阵元具有稳定的有源方向图、较宽的半功率波瓣宽度以及较好的极化性能。     

一种小规模超宽带相控阵天线设计

目前基于阵元间强耦合效应已设计出超宽带相控阵天线,但是其规模较大。针对规模小或者在扫描方向上规模小,如何增强阵元间耦合而实现超宽带相控阵天线的问题,采用平衡对踵Vivaldi天线(BAVA)作为天线单元,优化天线单元辐射金属的形状,并采用镜像法布阵天线单元设计出一个小规模4×16的斜极化超宽带相控阵天线。仿真和试验结果表明,采用的方法可以增强小规模超宽带相控阵天线的阵元间耦合效应,实现频率0.8f0~2.0f0驻波比小于2,法向增益达17.34~23.0 dBi,在±45°范围内实现无栅瓣扫描。该小规模超宽带相控阵天线已在实际工程中应用。     

改进型超宽带Vivaldi天线设计与仿真

在传统Vivaldi天线结构的基础上,设计了两种适用于宽带信号收发系统的改进型渐变槽Vivaldi天线以及同轴馈电型对踵Vivaldi天线,并利用电磁仿真软件HFSS对这两种Vivaldi天线的性能进行优化分析.通过对不同结构Vivaldi天线的对比分析结果可以看出改进型渐变槽Vivaldi天线和同轴馈电型对踵Vivaldi天线在频段、带宽、驻波比等方面均达到宽带传输系统的设计要求.     

新型强耦合宽带双圆极化阵列天线

空间飞行器由于受到动力和负载的限制, 需要尽可能使搭载的天线轻质小型化.文中提出了一种新型强耦合双圆极化轻质天线.天线单元采用H型缝隙耦合和增加寄生贴片方法, 提高了天线带宽.同时, 通过在辐射贴片、寄生贴片上开圆形槽, 以及金属反射板栅格化的处理, 明显地减轻了天线的质量.采用这种新型天线单元, 设计了8单元的宽带双圆极化阵列天线.仿真结果表明:该阵列天线的中心频率为433 MHz, 左旋和右旋圆极化的相对轴比(Axial Ratio, AR)带宽(AR < 3 dB)分别达到了24.4%和23.2%, 有效实现了小型轻质化宽频带双圆极化阵列天线.     

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。     

Fractal based ultra-wideband antenna development for wireless personal area communication applications

This paper presents a bandwidth enhanced, compact planar ultra-wideband antenna design for wireless personal area communication (WPAN) applications. The proposed antenna has fractal based geometry and is constructed using several iterations of a pentagon slot inside a circular metallic structure. The partial ground plane of the basic radiator is tapered, defected and a U slit is etched out from the microstrip feed to improve the −10 dB |S11| bandwidth. The proposed fractal based antenna has an impedance bandwidth from 2.9 GHz to 15 GHz with low profile configuration and is fabricated on FR4 substrate with dimensions of 32 mm × 32 mm × 1.6 mm. To authenticate the designed prototype, the antenna is fabricated and tested for impedance and radiation characteristics. The designed antenna has stable radiation characteristics in the operating band. Furthermore, the antenna is validated for its applicability in WPAN, by calculating fidelity factor through time domain analysis along with the transmission coefficient and group delay measurements.     

Compact omnidirectional band-notch ultra-wideband antenna

A novel ultra-wideband printed monopole antenna with a band-notch characteristic and stable omnidirectional radiation is presented. The antenna design adopts a bevelled square patch as a monopole, a double-feed technique and a microstrip feeder embedded with an inverted U-shaped slot. Good agreement between simulation and experiment shows that the proposed antenna achieves an impedance bandwidth of 3.05-5.15 and 6.02-10.84 GHz for VSWRles2, a stable omnidirectional radiation and a low cross-polarisation level.     

Electromagnetic band gap coupled tri-notched miniaturized ultra-wideband antenna loaded with slot and parasitic strip

An electromagnetic band gap (EBG) coupled miniaturized tri-notched printed ultra-wideband (UWB) monopole microstrip antenna having dimensions of 22 mm × 26 mm × 1.6 mm loaded with a slot in radiating patch and a parasitic strip in the ground plane has been presented. The proposed structure incorporates a square-shaped metallic radiating patch with a square EBG structure adjacent to the microstrip feed line, a U-shaped meandered slot over the radiating element, and a U-shaped parasitic resonator at the ground plane beneath the radiating element, to reject the C-band satellite downlink (3.7 to 4.2 GHz), WLAN frequency band (5.15 to 5.85 GHz), and X-band satellite downlink (7.25 to 7.75 GHz) frequency bands, respectively. The designed antenna operates in the frequency range from 3 to 11.1 GHz, with an impedance bandwidth of 8.1 GHz and a percentage bandwidth of 114%. Modification steps incorporating into the reference antenna to achieve the desired design objectives have been discussed, along with parametric studies. The proposed design has been simulated using Ansys HFSS, and measurement has been taken using standard measurement technique and compared with the simulated results.     

Novel Design of a High-gain and Wideband Fabry-Pérot Cavity Antenna Using a Tapered AMC Substrate

A high-gain and wideband electromagnetic bandgap (EBG) resonator antenna with a tapered artificial magnetic conductor (AMC) ground plane is presented. The proposed EBG resonator antenna is comprised of a frequency selective surface (FSS) superstrate with a strip dipole array and an AMC ground plane with tapered rectangular patches. The realized gain and the bandwidth of the antenna can be improved simultaneously by using the tapered AMC where the phase difference of the reflected waves from the patches with different length is within 180° and the destructive interference among them can be considerably reduced. The maximum gain is increased about 2∼3 dB and the bandwidth is improved about 2.5 times compared to when the uniform AMC is used.     

A 60-GHz Wideband Slot Antenna Based on Substrate Integrated Waveguide Cavity

This paper proposes a new wideband W-band substrate integrated waveguide (SIW) cavity-backed slot (CBS) antenna. The SIW cavity suppresses the backward radiation and ensures this antenna have a very low profile (only about 4% of the operating wavelength). Several techniques, such as slot resonator with semicircular end, quarter-wavelength microstrip resonator, are introduced to improve impedance matching. The studied results demonstrate that this antenna has wide operating bandwidth in 54.3–67 GHz (about 20.9% of the fractional bandwidth), unidirectional radiation pattern and good linear polarization characteristic. These properties are very suitable for RF front-end system-on-package (SoP) design in millimeter wave wireless communication systems.