一种超宽带平面天线的设计研究

设计一种小型超宽带平面天线,该天线为共面波导馈电的宽槽天线,其辐射贴片采用矩形与椭圆结构相结合的形式,并采用导带的圆形过度方法进行阻抗变换。在-10dB时的反射损耗带宽覆盖3.1～10.6GHz的频带范围,满足FCC所要求的超宽带无线通信带宽的要求,具有较好的应用前景。     

利用科赫分形解耦的四端口紧凑型QSC UWB MIMO天线

提出一种利用共面波导(Coplanar Waveguide, CPW)馈电的四端口紧凑型准自互补(Quasi-self-complementary, QSC)超宽带(Ultra-Wideband, UWB)多输入多输出(Multiple-input Multiple-output, MIMO)天线。此UWB MIMO天线的整体尺寸为40 mm×30 mm×0.8 mm,由4个六边形准自互补辐射单元对称排列而成,印刷在介质板的一侧。介质板另一侧印刷科赫分形解耦枝节和新型正六边形双开口谐振环(double-split ring resonator, DSRR)阵列,分别提升低频和高频处天线单元间的隔离度。实验与测试结果表明,此天线的工作带宽为3.1 GHz～15.5 GHz,在大部分工作频段内,隔离度达到20 dB以上。此外,天线在整个工作频带内具有良好的辐射特性和稳定的增益。包络相关系数小于0.04,表明该天线能够很好地满足极化分集特性,可用于便携式UWB MIMO无线通信系统。     

一种新型的双陷波UWB天线研究与设计

为了有效地抑制窄带信号对超宽带系统的干扰,设计了一种新型双陷波平面超宽带天线,地板采用新型的缺陷地结构来扩展带宽,并通过在八边形天线的辐射贴片上加载互补开口谐振环、在馈线上开U形缝隙,使得天线在3.7～4.1 GHz和5.1～5.9 GHz频段内实现双陷波特性.分析了实现天线陷波的原理,研究了天线的尺寸参数对陷波的影响,并对所设计的天线进行了实物加工和测试.结果显示,该天线能够有效地抑制卫星C波段和无线局域网系统的干扰,远场方向图和增益特性良好,在整个超宽带系统工作带宽内具有较好性能,是一种能广泛应用于超宽带系统的新型超宽带天线.     

宽带接地共面波导的时域测量方法研究北大核心CSCD

宽带接地共面波导是校准示波器宽带探头的核心器件。为了准确测量示波器探头的带宽指标,获得宽带接地共面波导传输特性成为实现高精度校准的关键。运用时域自动网络分析仪的测量原理,基于飞秒激光激励皮秒电脉冲技术,采用二次测量法,构建了接地共面波导二次时域测量系统,通过两次测量的方式解算出宽带接地共面波导的冲激响应,从而得到频域带宽指标。以阵列通孔结构仿真设计接地共面波导,采用二次测量法测量加工样品,3 dB带宽达54.2 GHz,与仿真结果相比具有较好的一致性。定标后的宽带接地共面波导可以作为标准器件,用于示波器宽带探头的校准,其测量结果可有效溯源至脉冲波形参数国家基准。     

新型半模基片集成波导漏波天线

 为了设计一种结构简单、可靠性高的全向天线,提出了一种基于半模基片集成波导技术的漏波天线.这种天线是在半模基片集成波导结构的H壁增加4个对称振子形成的漏波辐射结构.使用电磁仿真软件对提出的天线结构进行了精确的建模,分析了介质厚度对天线带宽的影响,并对天线结构进行了优化,最后制作了天线测试样片进行实验验证.所设计的天线具有较宽的带宽和准全向辐射的特性,在7.3~9.7 GHz频段内具有良好的辐射性能,最大增益为5.8 dBi,测试结果验证了设计的有效性．     

基于交叉缝隙的陷波可重构超宽带天线

本文设计了一种基于交叉缝隙的陷波可重构超宽带天线.通过采用3×3圆形超表面,有效拓展了天线的工作带宽.通过在矩形接地面上刻蚀两组交叉缝隙,并控制缝隙中设置的二极管的通断实现了天线的陷波可重构.所设计的天线尺寸较小,控制方式简单.结果表明,所设计的天线可以工作在超宽带和陷波模式下,超宽带模式的-10 dB带宽为3.5 G...     

一种低交叉极化小口径超宽带天线的设计

在高精度近场法天线测量、平面波发生器应用等场合,工作频段通常受限于近场探头。为了克服开口波导探头的带宽限制,出现了基于Vivaldi天线的超宽带、小口径天线作为近场探头。然而,常见的Vivaldi天线是非对称结构,导致交叉极化性能较差。设计了一款低交叉极化小口径超宽带天线,采用5层对称结构改进了传统Vivaldi天线的非对称性,利用贝塞尔曲线设计渐变槽辐射结构、加载电阻和贴片以及刻蚀矩形斜槽,减小了交叉极化比和天线驻波,改善了天线辐射方向性图。该探头口径宽70 mm、长201 mm,在0.9～6 GHz频段内天线仿真所得交叉极化比优于40.9 dB,增益为-5.5～9.53 dBi,端口反射系数幅度低于-10 dB,其辐射方向性图在全频段不开裂、主波束指向不变。     

共形于圆柱载体的串联阵列天线性能研究

本文提出一种新型的可共形于圆柱载体的阵列天线.采用共面波导(CPW)串联馈电的方法实现了较宽的工作带宽.在此基础上,研究了圆柱形载体对该共形阵列天线性能的影响.结果表明:没有载体时,共形阵列天线的-10dB带宽为2.1~3.45GHz(相对工作带宽48.6%),最大增益为5.4dBi.加载相对介电常数介于1~8之间、厚度介于0~12mm之间的柱形圆管载体后,该共形阵列天线依然满足覆盖无线局域网(WLAN)2.4~2.48GHz的带宽要求,并且可以在-60℃~100℃的环境温度下工作,满足目前复杂的无线通信设备的使用需求.     

一种具有5.8GHz WLAN深度抑制特性的超宽带全向天线

为超宽带室内定位系统设计了一种具有5.8 GHz WLAN深度抑制特性的超宽带单陷波全向天线.采用“倒箭头”形贴片作为辐射单元,在矩形地面上刻蚀矩形开路槽和直角三角形截断,获得了宽的阻抗带宽;在辐射贴片上刻蚀1个半波长C形槽,并在地面上刻蚀1个半波长RSCSRR槽对,实现了5.8 GHz WLAN信号的深度抑制.仿真结果表明,天线的阻抗带宽为3.10 GHz～10.60 GHz, 5.8 GHz陷波处的电压驻波比达7.59.实测的S₁₁曲线与驻波比曲线与仿真结果吻合良好,验证了陷波的有效性;4 GHz, 6.5 GHz, 9 GHz频点的实测方向图表明天线在整个超宽带频段内具有良好的辐射特性和全向性,满足超宽带室内定位系统天线的设计需求.     

超宽带陷波差分天线

本文提出了一种具有阻带特性的超宽带(UWB)差分天线.通过在超宽带天线的接地板上增加两个对称的C形金属带(TSCSCS),实现超宽带的阻带特性,通过调整TSCSCS的长度可以调节阻带的中心频率,同时,TSCSCS也提高了天线在高频段的增益.天线的测量结果表明,天线的带宽为3.25~10.8GHz,阻带为5.9~7.25 GHz.在整个工作频带内,天线的辐射方向图较稳定且有较高的增益,最高增益达5.53dBi.     

Design of a Compact Monopole Antenna for UWB Applications

In this paper, a low cost, highly efficient and low profile monopole antenna for ultra-wideband (UWB) applications is presented. A new inverted triangular-shape structure possessing meander lines is designed to achieve a wideband response and high efficiency. To design the proposed structure, three steps are utilized to achieve an UWB response. The bandwidth of the proposed antenna is improved with changing meander lines parameters, miniaturization of the ground width and optimization of the feeding line. The measured and simulated frequency band ranges from 3.2 to 12 GHz, while the radiation patterns are measured at 4, 5.3, 6 and 8 GHz frequency bands. The overall volume of the proposed antenna is 26 × 25 × 1.6 mm3 ; whereas the FR4 material is used as a substrate with a relative permittivity and loss tangent of 4.3 and 0.025, correspondingly. The peak gain of 4 dB is achieved with a radiation efficiency of 80 to 98% for the entire wideband. Design modelling of proposed antenna is performed in ANSYS HFSS 13 software. A decent consistency between the simulated and measured results is accomplished which shows that the proposed antenna is a potential candidate for the UWB applications.     

Super Compact UWB Monopole Antenna for Small IoT Devices

This article introduces a novel, ultrawideband (UWB) planar monopole antenna printed on Roger RT/5880 substrate in a compact size for small Internet of Things (IoT) applications. The total electrical dimensions of the proposed compact UWB antenna are 0.19 λ_o × 0.215 λ_o × 0.0196 λ_o with the overall physical sizes of 15 mm × 17 mm × 1.548 mm at the lower resonance frequency of 3.8 GHz. The planar monopole antenna is fed through the linearly tapered microstrip line on a partially structured ground plane to achieve optimum impedance matching for UWB operation. The proposed compact UWB antenna has an operation bandwidth of 9.53 GHz from 3.026 GHz up to 12.556 GHz at −10 dB return loss with a fractional bandwidth (FBW) of about 122%. The numerically computed and experimentally measured results agree well in between. A detailed time-domain analysis is additionally accomplished to verify the radiation efficiency of the proposed antenna design for the ultra-wideband signal propagation. The fabricated prototype of a compact UWB antenna exhibits an omnidirectional radiation pattern with the low peak measured gain required of 2.55 dBi at 10 GHz and promising radiation efficiency of 90%. The proposed compact planar antenna has technical potential to be utilized in UWB and IoT applications.     

A Compact Rhombus Shaped Antenna with Extended Stubs for Ultra-Wideband Applications

Ultra-wideband (UWB) is highly preferred for short distance communication. As a result of this significance, this project targets the design of a compact UWB antennas. This paper describes a printed UWB rhombus-shaped antenna with a partial ground plane. To achieve wideband response, two stubs and a notch are incorporated at both sides of the rhombus design and ground plane respectively. To excite the antenna, a simple microstrip feed line is employed. The suggested antenna is built on a 1.6 mm thick FR4 substrate. The proposed design is very compact with overall electrical size of 0.18λ × 0.25λ (14 × 18 mm²). The rhombus shaped antenna covers frequency ranging from 3.5 to 11 GHz with 7.5 GHz impedance bandwidth. The proposed design simulated and measured bandwidths are 83.33% and 80%, respectively. Radiation pattern in terms of E-field and H-field are discussed at 4, 5.5 and 10 GHz respectively. The proposed design has 65% radiation efficiency and 1.5 dBi peak gain. The proposed design is simulated in CST (Computer Simulation Technology) simulator and the simulated design is fabricated for the measured results. The simulated and measured findings are in close resemblance. The obtained results confirm the application of the proposed design for the ultra-wide band applications.     

V-Shaped Monopole Antenna with Chichena Itzia Inspired Defected Ground Structure for UWB Applications

Due to rapid growth in wireless communication technology, higher bandwidth requirement for advance telecommunication systems, capable of operating on two or higher bands with higher channel capacities and minimum distortion losses is desired. In this paper, a compact Ultra-Wideband (UWB) V-shaped monopole antenna is presented. UWB response is achieved by modifying the ground plane with Chichen Itzia inspired rectangular staircase shape. The proposed V-shaped is designed by incorporating a rectangle, and an inverted isosceles triangle using FR4 substrate. The size of the antenna is 25 mm×26 mm×1.6 mm. The proposed V-shaped monopole antenna produces bandwidth response of 3 GHz Industrial, Scientific, and Medical (ISM), Worldwide Interoperability for Microwave Access (WiMAX), (IEEE 802.11/HIPERLAN band, 5G sub 6 GHz) which with an additional square cut amplified the bandwidth response up to 8 GHz ranging from 3.1 GHz to 10.6 GHz attaining UWB defined by Federal Communications Commission (FCC) with a maximum gain of 3.83 dB. The antenna is designed in Ansys HFSS. Results for key performance parameters of the antenna are presented. The measured results are in good agreement with the simulated results. Due to flat gain, uniform group delay, omni directional radiation pattern characteristics and well-matched impedance, the proposed antenna is suitable for WiMAX, ISM and heterogeneous wireless systems.     

Size reduction and bandwidth enhancement of snowflake fractal antenna

A new small-size and wideband fractal antenna in the shape of a snowflake is proposed. Various iterations of this fractal antenna with probe feed and capacitively coupled feed are compared and an optimised design is presented. It is shown that, with an air-filled substrate and capacitive feed, an impedance bandwidth >49% and, with a slot-loading technique, a reduction of about 70% in patch surface size compared with an ordinary wideband Koch fractal antenna are achievable. The simulation via a finite-element programme, and measured results on the return loss and the E and H-plane radiation patterns of the proposed antennas are presented and shown to be in good agreement.     

Compact coplanar waveguide-fed ultra-wideband monopole-like slot antenna

A simple and compact coplanar waveguide (CPW)-fed ultra-wideband (UWB) monopole-like slot antenna is presented. The proposed antenna comprises a monopole-like slot and a CPW fork-shaped feeding structure, which is etched onto an FR4 printed circuit board (PCB) with an overall size of 26 mm x 29 mm x 1.5 mm. The simulation and experiment show that the proposed antenna achieves good impedance matching, consistent gain, stable radiation patterns and consistent group delay over an operating bandwidth of 2.7?12.4 GHz (128.5%). Furthermore, through adding two more grounded open-circuited stubs, the proposed antenna design features band-notched characteristic in the band of 5?6 GHz while maintaining the desirable performance over lower/upper UWB bands of 3.1?4.85 GHz/6.2?9.7 GHz.     

Sectorised antenna array and measurement methodology for indoor ultra-wideband applications

A new sectorised antenna array (SAA) and measurement methodology are proposed for indoor ultrawideband (UWB) applications. The proposed SAA comprises of one centre element and six side elements. The one centre element and six side elements are arranged in a semi-spherical antenna array configuration. The measurement system and methodology for the coverage of the SAA are developed. The measured bandwidth of the SAA for voltage standing wave ratio (VSWR) <2 is 37.5%, ranging from 3.06 to 4.47 GHz. The boresight gain is more than 5.2 dBi across the impedance bandwidth. The proposed SAA is able to provide omni-directional pattern with an average gain of 5.2 dBi over the angles (0-3608). The discone reference antenna is used to measure the coverage of the proposed SAA. The proposed measurement study shows that the proposed SAA offers omni-directional coverage desirable in UWB indoor location and short-range communication systems.     

Multilayer bandstop filter for ultra wideband systems

A multilayer broadside-coupled microstrip-slot-microstrip structure is used to design a bandstop filter with a wide passband for ultra wideband (UWB) applications. The design procedure for the proposed filter is based on the conformal mapping technique and the even- and odd-mode analysis. The theoretical analysis indicates that value of the coupling factor between the top and bottom layers of the structure can be used to control the width of the stopband, whereas centre of that band can be controlled by the length of the coupled structure. To limit the passband of the proposed bandstop filter to 3.1 ?10.6 GHz, which is the specified bandwidth for UWB systems, a broadside-coupled bandpass filter is integrated with the proposed device. The simulated and measured results show that the proposed device achieve ,0.5 dB insertion loss across most of the passband and .20 dB insertion loss at the stopband. The device also shows a flat group delay across the passband with ,0.15 ns peak-to-peak variation. Hence, it is a suitable choice for the UWB systems that require a distortionless operation.     

一种改善超宽带MIMO天线隔离性能的方法

多输入多输出(Multiple-InputMultiple-Output,MIMO)技术是现代通信技术的发展趋势,为移动通信的迅速更迭提供了极大支持.设计了一种二端口的超宽带MIMO天线,其-10 dB阻抗带宽从3.3 GHz扩展到9.1 GHz.通过在天线接地板上蚀刻一条宽缝隙,并在其中添加音叉型枝节,改善了超宽带M...     

Multipatches multilayered UWB microstrip antennas

The authors present multipatches multilayered ultra-wideband (UWB) microstrip antennas. The antenna comprises a driven patch radiator with five parasitic patch radiators. Two antennas with different dielectric substrate combinations are studied. The antenna with low-high-low dielectric constant substrate combination (Antenna no. 1) has an improved performance in terms of impedance bandwidth, gain, overall antenna size and beam-squinting over the antenna with low-low-low dielectric constant substrate combination (Antenna no. 2). The low-high-low dielectric constant combination consisting of three dielectric substrates, namely low dielectric constant (ϵr = 3.38) for both bottom and upper substrate but, high dielectric constant (ϵr = 6.15) for middle substrate. Five parasitic patches and multi-dielectric layers are used for wide impedance bandwidth and less boresight gain variation with frequency. A measured 10 dB return loss bandwidth of 48% with boresight gain .5.0 dBi is achieved. Antenna no. 1 can have 8% wider impedance bandwidth, 40% overall area reduction and less beam-squinting compared with Antenna no. 2.