四臂螺旋天线设计与实现研究

文章介绍了四臂螺旋天线的结构特性和几何尺寸、螺旋模式;设计了一种小型四臂螺旋天线,采用巴伦平衡结构的自相移馈电方式馈电,将螺旋臂印刷在高介电常数陶瓷柱上,减小了天线的体积,通过仿真分析,该种天线具有良好的宽波束和圆极化特性。     

一种新型高增益小型化四臂螺旋天线

针对卫星通信、卫星导航设备中四臂螺旋天线低仰角增益低、馈电网络尺寸不能满足安装要求的问题,设计了一种新型四臂螺旋天线,采用折叠式威尔金森(Wilkinson)移相馈电网络馈电,采用类八臂渐变式螺旋臂的方法提升天线低仰角增益。天线仿真和测试结果吻合良好,结果显示,在±60°~±90°低仰角范围内天线增益提高了1~2 dB,天线轴比保持在2以内,馈电网络高度降低了1.5 cm。该四臂螺旋天线具有低仰角高增益、圆极化特性良好、尺寸小等特点。     

一种新型宽波束圆极化天线的设计

本文提出了一种新型的螺旋结构的天线，将角锥螺旋与四臂螺旋的结构巧妙的结合起来，并采用了自相移结构及渐进式的平衡馈电，经有限元法对其辐射特性进行分析和实测，结果都说明该种天线在实现宽波束圆极化的同时展宽了频带，且结构简单。     

宽频带圆极化缝隙螺旋天线的设计

研究了一种宽阻抗带宽和宽圆极化轴比带宽的缝隙螺旋天线。天线印制在由FR4 介质基板构建的 方形柱状结构的内外表面,两组长短不同的缝隙螺旋臂印制在介质基板外表面并延伸至天线顶部;一条弯折的微带 线作为馈电网络印制在介质基板内表面,通过对各缝隙耦合馈电,实现天线宽阻抗带宽和轴比带宽。实测结果表 明:天线尺寸为0. 111λ0 ×0. 111λ0 ×0. 221λ0(λ0 为北斗B2 中心频率1. 207 GHz 对应的自由空间波长),S11 ≤ -10 dB 的阻抗带宽为1. 158~1. 778 GHz,轴比≤3 dB 的圆极化带宽为1. 133~1. 918 GHz。该天线采用缝隙螺旋结构,通过 简易的馈电网络实现天线小型化和宽频带特性,在卫星导航系统中具有较好的应用前景。     

基于共形馈电网络的新型双频四臂螺旋天线

针对卫星地面手持终端系统对天线高效率宽波瓣的应用要求,文章提出一种新型双频印刷一体化四臂螺旋天线结构,通过两种方式提高其双频辐射效率:第一,每组辐射振子分成两个支路,分别以不同的长度、宽度和螺旋角度绕制以减少振子间耦合,同时覆盖两个不同的频点;第二,馈电网络和辐射振子进行一体化设计,提高其馈电效率。测试结果表明:在两个间距很近的频点(1.1倍频程)能够分别实现4.3dBi(低频)和4.2dBi(高频)的右旋圆极化增益,且4dBi以上右旋圆极化增益相对频带宽度分别为6%(低频)和5%(高频),圆极化3dB波瓣宽度均达到130°以上。该天线的双频点、宽波束、高效率性能适合于卫星通信手持终端系统应用。     

一种可调式自相移印制四臂螺旋天线

船载海事卫星(INMARSAT)通信天线波束宽度较窄,且在风浪下船体摇晃难以与低仰角处卫星进行通信。提出一种带有开槽巴伦的可调式自相移四臂螺旋天线,避免了馈电网络造成的横向面积过大等问题。天线长振子臂长度可微调,结合调整开槽巴伦上的移动环,可以局部改变天线通信频带。通过基于有限元算法的HFSS仿真和实验,得出该天线具有宽波束特性,3 dB 波瓣宽度约为165°。另外,可以实现左右圆极化互相转换,在较宽的角度下,天线轴比低于6 dB。该天线既可以作为海事卫星通信天线,又可以作为北斗、GPS 导航天线和测浪高所用的左旋圆极化天线。     

卫星导航终端的小型化方形四臂缝隙螺旋天线

设计了一种卫星导航终端的小型化四臂缝隙螺旋天线。天线为方形柱状结构,四条缝隙螺旋臂印制在介质基板外表面,馈电网络印制于介质基板内表面进行耦合馈电;馈电网络为弯折的微带线结构,并延伸至天线底部实现同轴馈电。天线尺寸为23.6 mm×23.6 mm×53.0 mm,实测结果表明,|S11 |≤-10 dB 的阻抗带宽为7.63%(1.512~1.632 GHz),轴比≤3 dB 的圆极化带宽为3.35% (1.556~1.609 GHz),在北斗B1频段中心频率(1.561 GHz)和GPS L1 频段中心频率(1.575 GHz)处增益分别达到4.31 dBi 和4.84 dBi。该天线采用缝隙螺旋结构,并通过简易的馈电网络耦合馈电实现螺旋天线的圆极化,结构小巧简单,适合批量生产,可应用于卫星导航系统终端设备。     

一种新型双频宽波束四臂螺旋天线的设计

根据移动卫星通信和卫星导航定位中对天线宽波束、圆极化和低仰角增益等要求,设计了一种新型的双频四臂螺旋天线,通过将工作于不同频段的两副结构类似的天线以内外共轴的方式形成一个整体来实现双频工作。天线通过开槽线巴伦实现平衡馈电,利用四臂螺旋自身的结构特点构造了90°自相移结构,获得了较好的宽波束圆极化特性。测试结果表明。实测和仿真结果基本一致,天线在两个频段都实现了较好的宽波束圆极化特性。     

宽波束四臂螺旋天线的设计

针对卫星通信中天线方向图的圆极化宽波束需求,给出了一种四臂螺旋天线的设计方法。通过无限巴伦实现平衡馈电,并利用四臂螺旋自身的结构特点构造了90°自相移结构,获得了较好的圆极化特性。采用Ansoft HFSS软件进行仿真及优化设计,加工了两种尺寸的天线实物,测试结果表明,实测和仿真结果较一致,两副天线的3dB波束宽度分别达到124°和180°。     

内外径馈电的八臂缝隙螺旋天线

设计一种新型串行馈电的双频段八臂缝隙螺旋天线。在天线缝隙螺旋臂的内径端对谐振于一个频段的四臂实行串行馈电,在外径端对谐振于另一个频段的四臂实行串行馈电,两个频段的螺旋臂互相交错以保证天线的轴对称性。这种结构的天线可实现双频段双接口输出,且双频段的圆极化方式任意组合。设计制作了GPS双频天线原型,测试结果表明,双频段上天线的法向增益大于5.7dBic,5°仰角以上的增益大于-6dBic,相位中心稳定度小于6mm。     

Design of a broadband planar cavity-backed circular patch antenna

This paper presents a design of a low-profile cavity-backed circular patch antenna for broadband applications. By using substrate integrated waveguide (SIW) based cavity and feeding mechanism, a planar cavity-backed patch antenna is realized. The proposed study demonstrates that a wide impedance bandwidth can be achieved by employing a rectangular SIW-based cavity underneath the conventional circular patch. Additionally, to generate circular polarization (CP), the patch has been reduced diagonally and shorted by a via-probe. Finally, a CP SIW-based antenna is designed and operating for a wide impedance bandwidth of 23.10% below −10 dB criteria, ranging from 9.09 GHz to 11.40 GHz and axial-ratio (AR) bandwidth of 270 MHz (10.30–10.57 GHz). The proposed design is fabricated by means of a printed circuit board (PCB) procedure. The simulated results are validated with the experimental one which agrees well with each other in the terms of S₁₁, antenna gain, AR and radiation patterns. Moreover, the proposed design exhibits unidirectional radiation characteristics with the measured peak gain of 6.6 dBic while maintaining planar integration.     

一种小型化缝隙圆极化印刷天线

设计了一种小型化的方形缝隙圆极化（CP）平面印刷天线,该天线采用在方形缝隙的四个边上均加载尺寸相同的矩形缝隙,使其具有更低的谐振频率;在方形缝隙的任一个加载缝隙里插入与外围地相连的细金属带条以产生微扰,激励出一对相位差90°的差分正交简并模,从而辐射圆极化波。对天线模型进行了优化设计和实物加工,测试结果表明,缝隙加载后天线谐振频率降低了约10%,验证了该小型化措施的有效性;另外该天线在3%的带宽内轴比<3 dB,具有良好的圆极化特性。     

Circularly Polarized Square Ring Slot Antenna with Arrow‐Shaped Structure

A novel design of a compact square‐ring slot microstrip antenna for achieving circular polarization (CP) operation is proposed and experimentally studied. By using an arrow‐shaped slot structure as a radiating element, the resonant frequency of the proposed antenna is significantly lowered, which can lead to a large size reduction for fixed frequency operation. The CP radiation characteristics are achieved by loading with proper asymmetry, which can be placed diagonally. A prototype of the proposed design is implemented and its performance is measured. Measured results show that radiation patterns with good CP characteristics are obtained at the resonant frequency.     

Frequency notched wide slot antenna for UWB/2.4 GHz WLAN applications

A compact frequency notched microstrip slot antenna for ultra-wideband (UWB) /2.4 GHz-band wireless local area network (WLAN) applications is proposed. The antenna is similar to a conventional microstrip slot antenna; however, by introducing a cross wide slot and a meandered-slotted stub, both compact size and frequency notched function can be achieved. It has been studied both numerically and experi- mentally for its impedance bandwidth, surface current distribution, radiation patterns, and gain. As will be seen, an operation bandwidth of over 4.61 ranging from 2.39 to 11.25 GHz for return loss lower than having a frequency notched band ranging from 4.75 to 5.85 GHz has been achieved, and good radiation performance over the entire frequency range has also been achieved.     

Circularly polarized antenna array with a new sequential phase feed network utilizing directional coupler

This is a presentation of a new design of circularly polarized (CP) antenna array having a wide axial ratio (AR) bandwidth and high-gain. It uses an innovative feed network which consists of compact directional couplers and a delay line describing a new kind of sequential phase (SP) feed network. Furthermore, in this work, we report and discuss the features of the feed network and single element. In the following, the single element antenna and the 2 × 2 CP antenna array are designed, prototyped and tested. The antenna array is designed by a multilayer microstrip structure with a compact size of 75 × 52 mm². Moreover, a metal reflector is utilized to enhance the antenna gain and achieve a unidirectional radiation pattern over the operating frequency band. According to the experimental results, the CP antenna array has a return loss (RL) bandwidth of 2.42 GHz (5.83–8.25 GHz), AR bandwidth of 1.11 GHz (6.76–7.87 GHz), and peak gain of 12.15 dBic. It seems that the performance of the proposed design is admirable for C-band frequency.     

SIW 耦合馈电阵列天线

提出一种新型宽带、结构紧凑的基片集成波导(SIW)背腔阵列天线的设计方法。所设计的SIW 阵列由紧密相连的背腔构成馈电网络,每个背腔上开宽缝作为辐射单元。SIW 背腔天线单元紧密排列,主要通过单元间感性耦合窗耦合馈电。SIW 背腔既是辐射单元又能实现能量分配,不需加载额外的馈电网络,因此该阵列结构十分紧凑。工作在20 GHz 频段的2×2 SIW 耦合馈电阵和4×4 SIW 耦合馈电阵已加工实现,仿真和测试结果表明所提出的SIW阵列设计方法简单、阵列结构紧凑、天线辐射性能良好。另外,本文研究了高增益大规模阵列天线的组阵方法。在2×2 SIW 耦合馈电阵的基础上,采用8×8 SIW 并联馈电网络加载天线子阵的方法设计了16×16 宽带高增益SIW 阵列天线并进行了加工测试。结果表明,采用这种组阵方法,天线阵阵元排布紧密,天线具有带宽宽、增益高、损耗低等优点。     

一种面向无线通信应用的宽频带圆极化天线阵

提出了一种新型宽频带2×2方形缝隙槽圆极化天线阵.天线阵包含一个连续旋转馈电结构、4个非对称U型馈电枝节和一个方形槽接地板.与传统圆极化天线阵所采用的L型馈电枝节不同,首次提出了一种新型非对称U形馈电枝节来改善天线的圆极化性能.利用这些枝节和缝隙槽作为微扰元素,缝隙槽天线阵可以激发多重圆极化谐振模式,进而产生宽频带的圆...     

Design and acceptance test of compact planar monopole antenna for LTE smartphone considering SAR,TRP, and HAC values

Eight different types of compact multiband planar antennas are proposed in this work for covering several long‐term evaluation (LTE) and Wi‐Fi bands in a smartphone antenna design. Gradual inclusion of several sections of a radiator on an inexpensive FR4 substrate is presented for receiving multi‐LTE bands with a handset device. Along with the presently available LTE bands, this antenna design approach also includes upcoming LTE in unlicensed spectrum and LTE licensed‐assisted access. Various techniques such as partial ground, branch line slit, parasitic structure, and meandered lines are used to achieve desired resonant frequencies, bandwidth, matching, and miniaturization. The final type of eight antennas has been implemented in the real‐world mobile phone handset. The interaction between the mobile handset and the human phantom model has been analyzed at few specific frequencies for evaluating specific absorption rate (SAR) and total radiated power (TRP) in a simulated manner. The same type is also studied as a hearing aid compatibility (HAC)–supported wireless device. The simulated results show the SAR and HAC values are at the acceptance level for this proposed design. A prototype model is developed and few parameters are measured for validation.     

一种宽带双极化赋形抛物盒喇叭天线

对空探测的雷达天线要求天线具有宽频带、全极化、高增益、方位面宽波束覆盖、俯仰面余割波束覆盖的特点,需要最大限度平衡大空域覆盖与高增益之间的矛盾,实现资源的最有效利用。本设计在传统抛物盒喇叭的基础上,在X 波段40%带宽范围内实现了一种方位面和俯仰面差异悬殊的波束性能,同时利用波导正交馈电技术实现双极化。仿真和试验均表明,设计的抛物盒喇叭天线在方位面能够实现30°波束覆盖,俯仰面实现0°~60°的大空域余割赋形波束。同时抛物盒喇叭还具有结构紧凑、馈电效率高的特点,有利于实现天线的小型化、轻型化设计。     

一种基于介质加载的地球覆盖波束天线设计

地球覆盖波束天线为低轨卫星与地面终端之间的数据传输建立了通道,文中研究了一种新型的介质 加载地球覆盖波束天线。基于介质加载的方法,文中提出了一种圆极化地球覆盖波束天线设计,该天线由馈电网 络、馈源和介质三部分组成,介质包括底部圆柱部分和顶部半球部分,馈源集成于介质内部。设计的地球覆盖波束 天线工作在C 波段,轴向0°~64°范围内增益在0 dBic 以上,40°方向增益为5. 2 dBic。天线尺寸紧凑,辐射波束具有 较好的空间截止特性,可满足立方星应用。