Small Printed Ultrawideband Antenna With Reduced Ground Plane Effect

A small printed antenna is described with a reduced ground-plane effect for ultrawideband (UWB) applications. The radiator and ground plane of the antenna are etched onto a piece of printed circuit board (PCB) with an overall size of 25mmtimes25 mmtimes1.5 mm. A notch is cut from the radiator while a strip is asymmetrically attached to the radiator. The simulation and measurement show that the miniaturized antenna achieves a broad operating bandwidth of 2.9-11.6 GHz for a 10-dB return loss. In particular, the ground-plane effect on impedance performance is greatly reduced by cutting the notch from the radiator because the electric currents on the ground plane are significantly suppressed at the lower edge operating frequencies. The antenna features three-dimensional omni-directional radiation with high radiation efficiency of 79%-95% across the UWB bandwidth. In addition, a parametric study of the geometric and electric parameters of the proposed antenna will be able to provide antenna engineers with more design information     

Design of a Planar Ultrawideband Antenna With a New Band-Notch Structure

A novel planar ultrawideband (UWB) antenna with band-notched function. The antenna consists of a radiation patch that has an arc-shaped edge and a partially modified ground plane. The antenna that makes it different from the traditional monopole antenna is the modification in the shape of ground plane, including two bevel slots on the upper edge and two semicircle slots on the bottom edge of the ground plane. These slots improve the input impedance bandwidth and the high frequency radiation performance. With this design, the return loss is lower than 10 dB in 3.1-10.6 GHz frequency range and the radiation pattern is highly similar to the monopole antenna. By embedding a pair of T-shaped stubs inside an elliptical slot cut in the radiation patch, a notch around 5.5 GHz WLAN band is obtained. The average gain is lower than -18 dBi in the stopband, while the patterns and the gains at frequencies other than in the stopband are similar to that of the antenna without the band-notched function.     

一种改进的小型化超宽带平面倒锥缝隙天线

提出了一种改进的超宽带平面倒锥缝隙贴片天线,通过调整倒锥缝隙和倒锥贴片的形 状,在更小尺寸条件下,实现了超宽带性能。天线总体尺寸为40 mm×40 mm× 1.5 mm。采用仿真软件分析了该天线的阻抗带宽、辐射方向图及增益特性。结果显示,该 天线的回波损耗小于-10 dB的带宽为2.2 GHz到大于16 GHz,在低频段具有全 向性,在3～14 GHz频段增益随频率的变化在4～7 dB之间。     

Design of a Multiresonator Loaded Band-Rejected Ultrawideband Planar Monopole Antenna With Controllable Notched Bandwidth

We present a new multiresonator loaded band-rejected planar monopole antenna for ultrawideband applications. The proposed microstrip-fed antenna is composed of a flared metal plate, a truncated ground plane, and two pairs of folded strips. By applying the resonance nature of the folded strips and the associated cross coupling effects, the proposed antenna demonstrates bandstop-filter-like response with bandwidth controllability at the targeted rejection band. To illustrate the antenna operating mechanism more clearly, an equivalent circuit model consisting of RLC lumped resonators and J-inverters is discussed and extracted. The antenna input admittance calculated with the help of the equivalent circuit model agrees reasonably well with the simulated one obtained by the full-wave simulator. The design concept and the simulated and experimental results including the return losses, radiation patterns, and gain responses versus frequencies are carefully investigated throughout the paper. A parametric study in terms of the bandwidth tunability of the proposed design at the notched band is performed. The effects of the finite size ground plane are studied in this paper as well.      

2.4GHz ISM频段平面印刷T型单极子天线的研究与设计

研究用于2.4GHzISM频段共面波导馈电的T型单极子天线。在T型天线水平臂和垂直臂的长度和宽度的四种组合情况下,给出了输入驻波比带宽的变化曲线图,并分别设计了两个(1#和2#)天线,其结构简单紧凑,且不带底板,易于集成和平面印刷。实测结果表明:在2.4GHz频段上,1#和2#天线分别获得了12.24%和16.33%的相对带宽(VSWR≤2)。     

A Dipole Excited Ultrawideband Dielectric Rod Antenna With Reflector

A novel very compact ultrawideband dielectric rod antenna with metallic reflector is presented. The desired HE11 mode on the rod is excited by a biconical dipole fed by a broadband tapered microstrip line balun. The input reflection remains below -10 dB from 3 up to 20 GHz. The antenna exhibits a flat gain larger than 7 dBi over the whole ultrawideband frequency range from 3 to 10 GHz approved by the Federal Communication Commission. An almost constant transient performance over a wide azimuth angle of plusmn40deg is obtained with small dispersion.     

Printed Planar Antenna for Wideband Applications

A compact planar antenna operating at a frequency range of 3–16 GHz is presented for wideband applications. The antenna is composed of a square patch fed by a microstrip line and a partial ground plane with a rectangular slot. The proposed antenna is very easy to be integrated with microwave circuitry for low manufacturing cost. The flat antenna has a compact structure and the total size is 29 mm × 22 mm. The result shows that the measured impedance bandwidth (VSWR≤ 2) of the proposed antenna is 3.2–15.44 GHz, with a notch from 4.7 to 5.8 GHz. The effects of the structure parameters on impedance bandwidth are also investigated. Details of the proposed compact planar antenna design are presented and discussed.     

超宽带印制矩形单极天线设计

针对超宽带通信应用,研究影响印制单极天线阻抗带宽的主要因素,设计基于微带馈电的小型化印制矩形单极天线。按照等效性原理,采用黄金分割比设计矩形振子体;通过接地面上端引入渐变梯形或凹形结构,同时调整馈入端接地面间隙,可实现印制矩形单极天线的超宽带特性。对具有渐变梯形或凹形接地面结构的微带馈电矩形印制单极天线结构进行优化,仿真结果表明,前者的阻抗带宽为2.96～17.94GHz,后者的阻抗带宽为2.9～13.3GHz,而两者的辐射方向基本保持不变。实测结果与仿真结果基本一致,达到了超宽带通信应用的要求。     

A Pentagonal Shaped Microstrip Planar Antenna with Defected Ground Structure for Ultrawideband Applications

A new compact pentagonal microstrip patch antenna with slotted ground plane structure, developed for use in ultrawideband applications, is studied in this article. The proposed antenna is mainly constituted by a pentagonal shaped patch antenna, a defected ground plane structure, two stubs, and four slots to improve the bandwidth. The designed antenna has an overall dimension of 30?×?17.59?×?1.6 mm³, for WIMAX/WLAN/WiFi/HIPERLAN-2 /Bluetooth/LTE/5G applications with a very large bandwidth starting from 2.66 to 10.82 GHz (S₁₁?<???6 dB). A parametric study of the ground plane structure was carried out to find the final and the optimal UWB antenna, and to confirm that the antenna has good performance and broader bandwidth. The proposed antenna prototype has been fabricated. The measured results indicate that the antenna has a good impedance matching. The antenna has an electrically small dimension with a good gain, a notable efficiency, and a wide impedance bandwidth, which makes this antenna an excellent candidate for ultrawideband wireless communication, microwave imaging, radar applications, and the major part of the mobile phone frequencies as well.

     

A Novel Compact Ultrawideband Antenna

In this paper, novel compact ultrawideband (UWB) antennas are proposed and successfully demonstrated within the bandwidth with the ratio of the maximum and minimum frequency to be more than 30. The results from electromagnetics (EM) simulation and measurement show good agreement. From the EM simulation results, the electromagnetic wave could be radiated to the free space through the antenna only if the antenna impedance were matched to one of its feed systems within the bandwidth. The developed antenna with a small size of 17 $times$ 17 $times $ 12 mm$^{3}$ shows voltage standing wave ratio (VSWR) of less than 2.5 : 1 from 3 to 100 GHz for the simulated data, and less than 2 : 1 from 3 to 50 GHz for the measured data. The gain of the developed antenna is more than 2 dBi from 3.1 to 10.6 GHz in the application of high-speed wireless digital communication system.      

A Single-Layer Ultrawideband Microstrip Antenna

A single-layer microstrip antenna for ultrawideband (UWB) applications, in which an array of rectangular microstrip patches was arranged in the log-periodic way and proximity-coupled to the microstrip feeding line, is presented. In order to reduce the number of microstrip patches in the UWB log-periodic arrays, a large scale factor ${rm k}=1.1$ was firstly reported and proved to be highly effective. Furthermore, instead of using an absorbing terminal loading, a novel loss-free compensating stub was proposed. Detailed parameters study was also presented for better understanding of the proposed antennas. The impedance bandwidth (measured ${rm VSWR}≪2.5$ ) of an example antenna with only 11 elements is from 2.26–6.85 GHz with a ratio of about 3.03:1. Both numerical and experimental results show that the proposed antenna has stable directional radiation patterns, very low-profile and low fabrication cost, which are suitable for various broadband applications.      

Printed Planar Monopole Antenna Design for Ultra-Wideband Communications

This paper presents an ultra wideband (UWB) planar printed monopole antenna fed by microstrip line. The antenna configuration contains a beveled ground plane. The beveled partial ground plane improves the impedance bandwidth. The measured frequency response demonstrates that the fabricated antenna exhibits an impedance bandwidth of 7.9 GHz over 3.1 to 11 GHz for VSWR < 2. The proposed antenna has ultra-wideband characteristics with omnidirectional radiation pattern and stable gain. Ultra-wideband performance of the proposed antenna is examined through the simulated surface current distributions. Measured results confirm that the antenna is suitable for UWB applications due to its compact size and high performance characteristics.     

Analysis of Planar Ultrawideband Antennas With On-Ground Slot Band-Notched Structures

Planar ultrawideband (UWB) antennas with on-ground band-notched structures are studied in this paper. Two different slot resonators, which feature quarter-wavelength and half-wavelength configurations, are embedded into the arc shaped ground plane of the circular disk patch antennas in order to obtain the desired band-rejection around 5.8 GHz. Their principles and characteristics are analyzed and compared in detail providing designers with in-depth understanding and useful design information. By choosing the quarter-wavelength slot resonator, the first spurious stopband can be pushed up to 3 $f _{0}$ ($f _{0}$ stands for the center frequency of the notch) and this antenna retains a super wide working band which spans from 1.62 GHz to 17.43 GHz. Performance in both the frequency domain and time domain for this antenna has been investigated carefully. The transmission response of a transceiving antenna system and their corresponding transient analysis are discussed at the end of this paper.      

Triple Band Dual Polarized CPW-Fed Planar Monopole Antenna

Wireless Personal Communications - This article presents a novel, simple and planar design of a CPW-fed tri-band and dual polarized monopole antenna. The proposed structure includes inverted...     

一种新型超宽带平面天线的FDTD分析

本文分析了一种具有超宽带特性的平面喇叭天线的阻抗和辐射特性.这种平面喇叭采用了新型的平衡馈电方式,结构简单,性能良好.采用时域有限差分方法(FDTD)分析天线时,吸收边界采用了完全匹配层技术(PML),并用环路径分方法(CP)处理了喇叭脊间窄缝,计算结果与实测数据比较,两者十分吻合.     

一种结构简单且陷波特性易调节的超宽带天线

设计了一种具有陷波特性的超宽带(UWB)天线,由一个圆环形贴片和部分地板组成,通过在贴片上 刻蚀一个弧形槽可以在不改变天线尺寸的基础上实现阻带特性。利用HFSS 仿真软件对该天线进行了仿真设计,设 计结果表明天线能够在2. 8-10. 8GHz 频带内实现宽带特性,并在5. 1-6GHz 处形成阻带。在此基础上,加工和测量 了天线模型,实测结果表明天线在工作频带内具有良好的辐射方向图和稳定的增益,而且天线尺寸小、结构简单。 非常适合应用于超宽带系统。     

天线增益频带特性确定的一种简单方法

介绍了用卫星源法测量卫星通信地球站天线的特点。简述了利用3dB和10dB波束宽度确定地球站天线增益的原理和方法。提出了利用外推法确定天线增益频段特性的一种简单方法。对波束宽度法测量增益的误差进行了分析和估算,其均方根误差±0.387dB。最后给出了某工程应用的C波段15m地球站天线增益测量结果,增益测量结果与理论计算结果吻合很好。     

WLAN双频印刷天线的设计

设计了一种应用于2.4GHz和5.8GHz无线局域网的双频天线。天线由4个印刷偶极子分别组成两对阵列而成,每一对阵列分别工作在各自的谐振频率上,从而实现双频。介质板背面印刷有巴伦进行耦合馈电。该天线具有结构简单、体积小、重量轻,成本低、易于集成等优点,适用于无线局域网系统。     

Ultrawideband Double Rhombus Antenna With Stable Radiation Patterns for Phased Array Applications

A broadband microstrip-fed printed antenna is proposed for phased antenna array systems. The antenna consists of two parallel-modified dipoles of different lengths. The regular dipole shape is modified to a quasi-rhombus shape by adding two triangular patches. Using two dipoles helps maintain stable radiation patterns close to their resonance frequencies. A modified array configuration is proposed to further enhance the antenna radiation characteristics and usable bandwidth. Scanning capabilities are studied for a four-element array. The proposed antenna provides endfire radiation patterns with high gain, high front-to-back (F-to-B) ratio, low cross-polarization level, wide beamwidth, and wide scanning angles in a wide bandwidth of 103%     

Ultrawideband PIFA With a Capacitive Feed for Penta-Band Folder-Type Mobile Phone Antenna

An ultrawideband planar inverted-F antenna (PIFA) with a capacitive feed in the folder-type or clamshell mobile phone for penta-band operation is presented. The antenna is placed at the hinge position between the main and upper ground planes of the folder-type mobile phone. With the use of the capacitive feed, a very wide operating bandwidth (3:1 VSWR or 6-dB return loss) of about 1.5 GHz (from 820 to 2345 MHz) is obtained, although the antenna is with a small radiating plate of size $8times 40 {rm mm}^{2}$ and a low profile of 7.8 mm above the top edge of the main ground plane. The very wide bandwidth covers GSM850/900/1800/1900/UMTS penta-band operation for the mobile phone in the open (talk) state. In addition, when in the closed (standby) state, although the groundplane condition greatly differs from that in the open state, the impedance matching over the operating bands can still be better than 6:1 VSWR (3-dB return loss), acceptable for standby operation in the practical applications.