Compact 5G Vivaldi Tapered Slot Filtering Antenna with Enhanced Bandwidth

Compact fifth-generation(5G)low-frequency band filtering antennas(filtennas)with stable directive radiation patterns,improved bandwidth(BW),and gain are designed,fabricated,and tested in this research.The proposed filtennas are achieved by combining the predesigned compact 5G(5.975–7.125 GHz)third-order uniform and non-uniform transmission line hairpin bandpass filters(UTL and NTL HPBFs)with the compact ultrawide band Vivaldi tapered slot antenna(UWB VTSA)in one module.The objective of this integration is to enhance the performance of 5.975–7.125GHz filtennas which will be suitable for modern mobile communication applications by exploiting the benefits of UWB VTSA.Based on NTL HPBF,more space is provided to add the direct current(DC)biassing circuits in cognitive radio networks(CRNs)for frequency reconfigurable applications.To overcome the mismatch between HPBFs and VTSA,detailed parametric studies are presented.Computer simulation technology(CST)software is used for the simulation in this study.Good measured S11 appeared to be<−13 and<−10.54 dB at 5.48–7.73 and 5.9–7.98GHz with peak realized gains of 6.37 and 6.27 dBi,for VTSA with UTL and NTL HPBFs,respectively which outperforms the predesigned filters.Validation is carried out by comparing the measured and simulated results.

Ultra-wideband bilateral tapered slot-line antenna fed by coplanar waveguide

In order to broaden the bandwidth of a tapered slot- line antenna （TSA）, a bilateral tapered slot-line antenna （BTSA） with a new feeding structure of coplanar waveguide （CPW） is developed. Based on the fact that the bandwidth limitation of TSA mainly depends on its feeding structure, an improved CPW-based feed structure etched on the backboard of the BTSA is adopted to perform traveling-wave transition. Both the simulation results and measurement data verify that the proposed feeding structure results in ＂high-pass＂ frequency response for antenna impedance matching. The voltage standing wave ratio （VSWR） is less than 2：1 when the frequency is higher than 3 GHz. The antenna gain exceeds 7 dBi with good radiation patterns when the bandwidth is from 4 to 16 GHz. This ultra wideband （UWB） antenna with a compact size is specially available for the electronic systems of counter-measure and microwave imaging.

Millimeter wave dielectric loaded exponentially tapered slot antenna array using substrate integrated waveguide for gigabit wireless communications

A new and upcoming application is the use of 60 GHz antennas for high date rate point-to-point connections to serve Gigabit(Gi-Fi)w ireless communications.The design of M illimeter w ave(M m W)antennas has to cope w ith the unadorned influences of manufacturing tolerances and losses at 60 GHz.In this paper,the concept of Substrate Integrated Waveguide(SIW)and Exponentially Tapered Slot(ETS)antenna w ere used together to design a high gain,efficient planar dielectric loaded antenna for M m W Gi-Fi w ireless communications at 60 GHz.The SIW is used to feed the antenna and a dielectric is utilized in front of the antenna to increase the gain.The dielectric loaded ETS antenna and compact SIW feed w ere fabricated on a single substrate,resulting in low cost and easy fabrication.The antenna w ith elliptical shaped dielectric loaded w as fabricated using printed circuit board process.The measured gain of the single element antenna is 10.2 dB,w hile the radiation efficiency of 96.84%is obtained at 60 GHz.The Y-junction SIW pow er divider is used to form a 1×4 array structure.M easured gain of the 1×4 array antenna is 13.3 dB,w hile the measured radiation pattern and gain are almost constant w ithin the w ide bandw idth of the antenna.

Design and Implementation of Step-Constant Tapered Slot Antennas for UWB Application

This paper presents the analytical design and high performance of step-constant tapered slot antenna (STSA) for ultra-wideband application. The return loss, radiation pattern, antenna gain, and level of cross polarization of this antenna are presented and analyzed. Utilizing Rogers (RO3006) substrate having a relative permittivity of 6.15, the proposed antenna provides the ultra-wideband (UWB) from 3.1 GHz to 10.6 GHz. It is observed that the return loss and gain are increased with increasing the step size. It has been observed from the simulation results incorporating CST microwave studio commercial software version 2015, the optimum return loss, directivity and gain are ?43 dB, 10.52 dBi and 10.20 dB, respectively, for 15 step size. Therefore, the newly proposed antenna will be a decent candidate for ultra-wideband application.

Broadband Feed for Low Cross-Polarization Uniplanar Tapered Slot Antennas on Low-Permittivity Substrate

A broadband feeding technique for the uniplanar tapered slot antenna (TSA) is presented. The TSA operates at a center frequency of 6.5 GHz with a 7 GHz bandwidth (107 percent). The antenna and feed are realized with a broadband microstrip-to-slotline transition on a low permittivity high frequency substrate, Rogers RT/Duroid 5880. The input impedance of the system is designed for 50 Ω compatibility with other system components, and the cross polarization is kept below –30 dB. The developed TSA system was simulated with commercially available electromagnetic software and manufactured. Measured results validate the design process and the antenna’s performance.

一种用于浅层探冰雷达的改进型宽带小型化TSA天线

该文介绍了一种用于高分辨率浅层探冰雷达(工作于500 MHz-2 GHz)的小型化TSA天线。该天线采用共面波导到槽线的转换结构实现馈电,天线的两侧边采用波纹结构,构成波纹结构的金属细条带的长度从馈点端到辐射孔径端逐渐减小。仿真结果表明,比之传统的TSA天线,该天线的工作频带可向低频扩展,同时低频段端射向增益能够提高3 dB。测试结果表明,除550 MHz附近的一个窄频带(S11<-8.2 dB)外,天线的阻抗带宽(S11<-10 dB)大于10:1。此外,在500 MHz-2 GHz内测量得到的端射向增益大于3.9 dBi,测量得到的辐射方向图与仿真值有较好的一致性。

一种X-KU波段TSA天线设计

渐变开槽天线(Tapered Slot Antenna)具有宽频带、结构灵巧、易于电路集成和组成相控阵列等优点,但是通过分析和设计常规的指数型TSA天线,发现其存在后瓣和旁瓣较大、增益较低的缺点。通过改进天线整体结构和局部开槽的方法,优化了常规TSA天线表面和渐变槽线边缘的电流分布,并利用HFSS设计了一付工作于X波段、KU波段改进型TSA天线,与设计的常规天线TSA相比,天线主辐射方向3dB波瓣宽度增大,最大增益提高,后瓣和副瓣得到了一定的抑制。

12-20GHz的TSA天线

该文设计并实现了一个用于超宽带(UWB)系统的TSA天线。计算结果与测量结果表明:工作频段为12-20GHz;天线的半功率波束宽度大于40°,方向图随频率的变化很小;天线的最大增益随频率增大而变化,基本呈增大趋势。该TSA天线基本满足UWB系统对天线的要求。

TSA增益的影响因素

文中设计了3个相同介质的超宽带渐变线天线(A、B和C),并在9 GHz～18 GHz范围内,比较了它们的增益。结果表明,渐变线天线的表面上渐变槽线以及辐射口径上场相位分布的均匀性对增益的影响很大。渐变槽线的长度D及开口宽度H分别增大到5.2倍和2.5倍,天线的增益在频段内增大了至少3.92 dB,因此渐变槽线开口方式对增益有重要影响。同时,天线辐射口径上的相位分布均匀,对于提高天线增益也是至关重要的。

TSA线性阵列的脉冲辐射特性分析

传统的超宽带天线概念是在频域下定义的,有些不能作为时域脉冲天线使用。首先介绍了TSA天线的工作原理,及其线性阵列的脉冲辐射特性,在时域上用逼近法对TSA天线脉冲辐射场进行了分析。在此基础上,分析了阵单元等间距和非等间距放置对线性阵列方向图的影响,并研究了在脉冲触发延迟时线性阵列的辐射特性。实验结果表明,当阵列的电尺寸一定时,阵单元非等间距放置不仅得到很好的方向图,而且旁瓣也得到了抑制;通过控制阵单元脉冲触发延迟时间,可以实现对天线阵列进行电子扫描。

Analysis and Design of Tapered Slot Antenna for Ultra-Wideband Applications

The tapered slot antenna, such as Vivaldi, has been widely used due to its ultra-wideband, high gain, simple feed structure, and easy fabrication. However, there is no rigorous analytical theory for this type of antenna. This paper analyzed the metal parts of a tapered slot antenna in a conical coordinate system with the medium analyzed in rectangular coordinates. This mixed mode gave an approximate analytical form for the tapered slot antenna with the field distribution and radiation characteristics. A planar tapered slot antenna was proposed according to the results of the analysis methods. Measured and simulated results demonstrate the antenna performance. The antenna shows good impedance matching over a wide bandwidth of 9 GHz, from 2 GHz to 11 GHz, and good radiation patterns. It is suitable for ultra-wideband applications.

Design and Analysis of Antipodal Vivaldi Antennas for Breast Cancer Detection

This paper presents the design and analysis of antipodal Vivaldi antennas(AVAs)for breast cancer detection.In order to enhance the antenna gain,different techniques such as using the uniform and non-uniform corrugation,expanding the dielectric substrate and adding the parasitic patch are applied to original AVA.The design procedure of two developed AVA structures i.e.,AVA with non-uniform corrugation and AVA with parasitic patch are presented.The proposed AVAs are designed on inexpensive FR4 substrate.The AVA with non-uniform corrugation has compact dimension of 50×50 mm2 or 0.28λL×0.28λL,whereλL is wavelength of the lowest operating frequency.The antenna can operate within the frequency range from 1.63 GHz to over 8 GHz.For the AVA with parasitic patch and uniform corrugation,the overall size of antenna is 50×86 mm2 or 0.24λL×0.41λL.It can operate within the frequency range from 1.4 GHz to over 8 GHz.The maximum gain for AVA with non-uniform corrugation and AVA with parasitic patch and uniform corrugation are 9.03 and 11.31 dBi,respectively.The corrugation profile and parasitic patch of the proposed antenna are optimized to achieve the desired properties for breast cancer detection.In addition,the proposed AVAs are measured with breast phantom to detect cancerous cell inside the breast and the performance in detecting cancerous cell are discussed.The measured result can confirm that the proposed AVAs can detect unwanted cell inside the breast while maintaining the compact size,simple structure and low complexity in design.

渐变槽天线端射特性优化设计

该文在优化渐变槽天线结构基础上,采用栅形开槽和加载周期结构,设计了一款平面端射天线。通过数值模拟,分析了栅形开槽和周期结构对天线辐射特性的影响。该结构在1~3.5 GHz频带内,明显改善了渐变槽天线的端射特性。天线样机测试结果表明,该天线在1~3.5 GHz内,驻波系数小于2,增益约为7 d Bi。天线的群时延相对平坦,时域波形振铃较小,可以应用于脉冲体制雷达。

渐变槽线天线的参数分析与设计

研究了渐变槽线宽带宽角扫描天线阵列的关键参数进行了研究,提出了2种新的改善扫描驻波的方法对渐变槽线天线的研究。一是天线单元内部的结构参数,包括带状线开路段、圆形槽谐振腔、槽指数率、槽长度;另一个方面是阵列中的排布,包括阵列栅格距离、栅格形状。仿真分析借助HFSS进行,最后给出了结果,带宽大于3∶1,E面H面扫描角大于45°。

一种新型超宽带渐变槽线天线设计

设计并制作了一种新型微带馈电的渐变槽线天线.采用改进的微带-槽线过渡,更好地解决了超宽带天线的阻抗匹配问题.提出一种新型渐变辐射曲线,有效地改善了低频段的匹配特性.实物样机的测试结果表明,在0.92-14.25 GHz频带内该天线的电压驻波比小于2.0∶1,带宽比达到15.4∶1,而且其带内辐射方向图的前后比大于15 dB,交叉极化低于-18 dB.

低剖面渐变槽线天线单元设计

基于有限元仿真软件通过设置周期性边界条件的方法,分析了影响渐变开槽天线单元宽带宽角扫描性能的关键因素。通过在安装天线阵列的反射面上铺覆新型阻抗匹配材料,克服了天线高度对驻波带宽的限制,实现了天线的小型化设计。加工制作了一个20×16天线单元的实验小型面阵,并对其有源扫描驻波进行了测试。实测结果与仿真结果吻合,表明该天线在8GHz～12GHz带宽内±45°扫描范围内性能优异,可广泛应用于宽带宽角扫描相控阵天线系统。

超宽带平面渐变开槽印刷天线阵的实验研究

采用共面波导到槽线的超宽带馈电结构,研制出用于接收阵列的超宽带渐变开槽印刷天线。在外场用示波器测量H面的时域方向图,结果表明:该阵列天线适合于用作实际的超宽带雷达接收天线阵。

一种新型正交双极化渐变槽线天线

提出了一种新型的正交双极化渐变槽线天线。它具有宽频带、高隔离、低交叉极化的特性。文中首先研究了该渐变槽线单元各结构参数与天线性能的关系,以此为基础设计了正交双极化的渐变槽线天线,在4.9∶1频带范围内VSWR小于2∶1,两端口间的隔离度优于25 dB。因此,该天线可用作移动通信的基站天线。

UHF波段开槽天线宽带阻抗特性分析

该文采用时域有限差分法 (FDTD)对开槽天线在 UHF频段的宽带阻抗特性进行了分析计算。文中给出了计算所得到的一个Vivaldi天线的宽带驻波参数。通过与实验结果相比较可以看出,两者比较吻合,从而证明该文采用的分析模型和处理方法是可行有效的。根据得到的结果,开槽天线的驻波比至少在2个倍频程范围内变化不大,符合宽带工作的要求。

基片集成波导正弦渐变槽单脉冲天线

为拓展工作带宽,以传统正反渐变槽天线为基础,利用基片集成波导馈电,该文提出了两种高增益、宽频带的正弦渐变槽天线。利用矩形波导3 dB定向耦合器和90°移相器工作原理设计了半模基片集成波导单脉冲馈电网络,进而得到了对称型和非对称型正弦渐变槽单脉冲天线,带宽均超过了3.0 GHz,带内和波束最大增益在9.0 dBi左右,差波束零深在10.0 GHz处均低于-20 dB。其中,非对称型正弦渐变槽单脉冲天线具有更宽的工作频带和更平稳的天线增益,可以广泛应用于微波定向探测系统中。