Compact CPW-fed dual-band antenna

A novel coplanar waveguide (CPW) antenna is proposed for dual-band WLAN applications. It comprises a rectangular patch, a rectangular notch cut at the lower edge of the patch and a CPW transmission line. The rectangular patch together with the ground plane of the coplanar waveguide radiates at the lower frequency band, 2.4 GHz for IEEE 802.11b/g, while the rectangular notch resonates in the upper band, 5.2/5.8 GHz for IEEE 802.11a. The designed antenna is only 32 × 5 mm, which can provide stable omnidirectional radiation patterns with an average gain of 2 dBi in both the bands. The antenna is very compact and suitable for 2.4 and 5.2/5.8 GHz WLAN operations.     

一种小型化双频天线的设计与分析

提出了一种小型化宽频带双频天线的设计。该天线由一个E形微带贴片和一个偶极子天线组合而成,产生高低2个频率,且低频段带宽可控。仿真的-10dB阻抗带宽分别为83MHz(2.4～2.485GHz)和812MHz(5.1～5.912GHz)。能够覆盖IEEE802.11b/g(2.4～2.483GHz)和IEEE802.11a(5.15～5.825GHz)工作频段,并对仿真结果进行了分析。同时给出的设计双频段宽带小型化天线的方法,可以对高低2个频段分开设计,对工程实践有一定的指导意义。     

A compact microstrip fed dual polarised multiband antenna for IEEE 802.11 a/b/g/n/ac/ax applications

A compact microstrip fed dual polarised multiband monopole antenna for IEEE 802.11 a/b/g/n/ac/ax communication based applications is presented. The antenna is circularly polarised in IEEE 802.11 b/g bands while linearly polarised in IEEE 802.11 a/n/ac/ax bands. The asymmetric U-shaped slot in the ground plane of proposed antenna is used to introduce the necessary 90° phase shift between two orthogonal electric field vectors necessary for circular polarisation. The Ω-shaped slot on patch is used to introduce a band elimination notch between the usable frequency bands. The radiation characteristics of the proposed antenna (at 2.4 GHz) can be changed from left hand circular polarisation (LHCP) to right hand circular polarisation (RHCP) by replacing asymmetric U-shaped slot with its mirror image on the opposite side of ground plane. The proposed antenna has a wide impedance bandwidth of 110.8% and can also be used in various applications including worldwide interoperability for microwave access (WiMAX) and IEEE 802.11p standard based V2V (Vehicle to Vehicle) communication.     

Compact dual-band patch antenna using spiral shaped electromagnetic bandgap structures for high speed wireless networks

This paper presents a compact dual-band slot antenna for 1.8/2.4 GHz WLAN applications using electromagnetic bandgap (EBG) structures. The slotted rectangular radiating element is surrounded by a spiral-like EBG. The antenna size is very compact (60 mm × 60 mm × 3.27 mm), and can be integrated easily with other RF front-end circuits. The working frequency of the patch antenna falls inside the EBG which will lead to the suppression of the surface waves. It is demonstrated that the proposed antenna can completely cover the required bandwidths of IEEE 802.11b/g and IEEE 802.11a with satisfactory radiation characteristics. The simulation is carried out using the finite integration time domain method (FITD) analysis technique. The EM simulated return loss, gain, directivity, radiation pattern, antenna efficiency and VSWR are presented for proposed antenna array. Good agreement is achieved between the simulated and measured results.     

Compact coplanar waveguide fed ultra wideband antenna with a notch band characteristic

A coplanar waveguide (CPW) fed ultra-wideband (UWB) antenna with a notch band characteristic is presented for 2.4 GHz and UWB applications. The bandwidth is broadened by embedding two inverted L-shaped slots in the CPW ground and the notch band is achieved by etching a rectangle slot in the CPW ground. The notched band can be controlled by adjusting the length of the rectangle slot and the two inverted L-shaped slots. Experimental and numerical results show that the proposed antenna with compact size of 28 × 21 mm², has an impedance bandwidth range from 2.38 GHz to 12.0 GHz for voltage standing-wave ratio (VSWR) less than 2, expect the notch band frequency 5.0–6.0 GHz for HIPERLAN/2, IEEE 802.11a (5.1–5.9 GHz) and C-band (4.4–5 GHz) for satellite and military applications.     

用于WLAN的双频天线的设计与实现

提出了一种应用于无线局域网（WLAN）的新型双频天线。该天线采用微带线馈电的方法,其辐射面呈阶梯形,接地面为＂工＂型宽缝结构,可以覆盖IEEE802.11a/b/g（2.4～2.484GHz,5.15～5.825GHz）频段标准。其回波损耗小于10dB的阻抗带宽在2.4GHz频段可达160MHz（2.4～2.56GHz）,在5GHz频段的可达1.32GHz（5.05～6.37GHz）。整个天线在42mm×52mm、介电常数为4.5、厚度为1.5mm的FR4介质基片上实现。结果表明,该天线具有十分良好的应用潜质。     

基于复合辐射器的WLAN/WiMax多频CPW微带天线

提出了一种图形结构简单,可同时工作于WLAN和WiMax频段,且具有甚好的带宽性能的新型结构微带天线。该天线辐射器由三角形、矩形和圆形辐射单元组合而成,采用共面波导(CPW)进行馈电,并利用微扰量加载调谐天线的工作频率。由此设计制作的天线实测结果表明:在802.11b/g(2.4～2.4835GHz)频段,相对阻抗带宽为34%,回波损耗优于-10dB的频段覆盖为2.03～2.87GHz;在WiMax(3.4～3.7GHz)频段,相对阻抗带宽为37%,回波损耗优于-10dB的频段覆盖为3.17～4.37GHz;在802.11a(5.15～5.825GHz)频段回波损耗优于-10dB的频率范围覆盖为4.91～6.83GHz。该天线尺寸为65mm×50mm×2mm,可以集成应用于相关微波电路系统中。文中还给出了天线的设计尺寸,并对仿真和实测结果进行了对比与讨论。     

Switched WLAN-wideband tapered slot antenna

A switched band antenna that has a capability to operate in dual-band WLAN mode (2.4-2.485 GHz and 5.725-5.875 GHz), a single band WLAN mode of 2.4-2.485 GHz and a wideband mode (2.2-7.2 GHz) is presented. The antenna is based on a tapered slot antenna, which has a defected ground structure containing two switchable ring and two rectangular slots to provide a switched band property. Measurement results on a prototype antenna, with an ideal switch, fully demonstrate the performances of the proposed designs. The proposed antenna is suitable for use in a base station or an access point for WLAN and wideband applications and may be also useful in future multimode radio systems.     

Dual-band triangular patch antenna with modified ground plane

A triangular patch antenna with a parasitic element over a modified small ground plane is presented. The antenna operates at two frequency bands with bandwidths exceeding 20% at the 2.45 and 5 GHz network bands. The ground is modified by cutting a large rectangular slot in it that allows tuning of the frequency bands and adjustment of the band spacing ratio     

Ultra-Wideband and Uni-Directional Radiation Slot Antenna for Multi-Band Wireless Communication Applications

In this paper, a ultra-wideband slot antenna is proposed and developed for multi-band wireless communication applications. The radiating slot is fed by a microstrip line with a microstrip fork shaped tuning stub and backed by a finite metallic reflector. The frequency characteristic and radiation performance of the proposed antenna are successfully optimized and the related prototypes are fabricated and tested. The measured results show that the impedance bandwidth can cover the band from 1.85 to 6.1 GHz with return loss of better than 10 dB. The obtained patterns display a high gain and uni-directional radiation patterns within interested bands. With these features, the proposed structure is suitable for application in wireless communication systems, where a single antenna is needed to operate at multi-bands simultaneously, such as PCS (1.85–1.99 GHz), UMTS (1.92–2.17 GHz) and all WLAN bands (2.4–2.48 GHz, and IEEE802.11a WLAN applications: 5.15–5.35 and 5.725–5.825 GHz).     

Ultra-wideband tapered slot antenna with band cutoff characteristic

A novel ultra-wideband (UWB) tapered slot antenna (TSA) is proposed that has both enhanced impedance bandwidth enough to cover UWB systems and band cutoff characteristic of 5 GHz WLAN band limited by IEEE802.11a and HIPERLAN/2. To achieve these two characteristics of wide bandwidth and partial band cutoff at the TSA, a broadband microstrip-slotline transition with multi-arm stubs and /spl lambda//4 short stubs, respectively, is used. From measured results, it is observed that wide bandwidth of about 2 octaves from 2.8 to 11.09 GHz for the VSWR<2 is achieved, while 5.05-5.93 GHz is cutoff with the radiated power of this cutoff band effectively suppressed as about -9 dB for the peak power level of other bands.     

Macro-micro frequency tuning antenna for reconfigurable wireless communication systems

A small-sized (radiator sime10times8 mm) microstrip monopole antenna for reconfigurable macro-micro frequency tuning is presented. The proposed antenna operates in WiBro (2.3-2.4 GHz) and WLAN 802.11a/b (2.4-2.48 GHz/5.15-5.35 GHz) service bands with a constant antenna gain. Two frequency tuning diodes, a pin diode and a varactor, are incorporated into a meander type radiator. The pin diode is used for frequency switching (macro-tuning) between 2 GHz band and 5 GHz band. In addition, the varactor is used for frequency tuning (micro-tuning) within wireless service bands (2.3-2.48 GHz and 5.15-5.35 GHz) to produce constant antenna gain     

Controllable Band‐Notched Slot Antenna for UWB Communication Systems

We propose a slot antenna consisting of a rectangular slot on the ground plane, fed by a microstrip line with a rectangular‐ring‐shaped tuning stub that can be deployed in ultra‐wideband (UWB) communication systems to avoid interference with wireless local area network (WLAN) communication. Our antenna can achieve a single band‐notched property from the 5 GHz frequency to the 6 GHz frequency owing to a controllable band notch that uses L‐ and J‐shaped parasitic elements. The antenna characteristics can be modified to tune the band‐notched property (4 GHz to 5 GHz or 6 GHz to 7 GHz) and the bandwidth of the band notch (1 GHz to 2 GHz). Furthermore, the shifted notch with enhanced width of the band notch from 1 GHz to 1.5 GHz is described in this paper. The UWB slot antenna and L‐ and J‐shaped parasitic elements also provide the band‐rejection function for reference in the WiMAX (3.5 GHz) and WLAN (5 GHz to 6 GHz) regions of the spectrum. Experiment results evidence the return loss performance, radiation patterns, and antenna gains at different operational frequencies.     

一种小型陷波多用途超宽带天线

提出了一种小型陷波多用途超宽带微带天线。该天线与一般的宽缝隙微带天线类似,通过在矩形调谐支节上开V形缝隙获得了陷波特性。通过数值仿真和实验测量,对天线的阻抗特性、方向图和增益进行了研究。结果显示该天线在2.4到11GHz频段内驻波比小于2,在5.15~5.95 GHz范围内具有陷波特性。同时该天线还可覆盖2.4GHz无线局域网(WLAN)频段,在整个工作频段内有良好的辐射方向特性。     

Compact One-Sixth Mode Substrate Integrated Waveguide Based Antennas for Wireless Communication and Public Safety Systems

The authors have chosen a hexagonal SIW cavity and designed it to resonate at the fundamental TM₀₁ mode at 5.9 GHz. The cavity is then bisected along its diagonal to produce a semi-hexagonal half-mode substrate integrated waveguide antenna, having a center frequency of 5.57 GHz lying within IEEE 802.11a WLAN U-NII 2C band. The half-mode SIW antenna depicts a gain of 5.5 dBi. A furthermore division of the full mode parent hexagonal resonator into six equal parts, each an equilateral triangle, constitutes the one-sixth mode of the parent cavity. This one-sixth mode SIW antenna operates at the resonating frequency of 5.4 GHz unlicensed band producing a gain of 5.38 dBi and finds suitable application in wireless communication systems. The antenna is further miniaturized with the inclusion of double T-shaped slot. This miniaturized antenna resonating at 4.96 GHz with a gain of 4.99 dBi is very apt in its use for public safety systems in the IEEE 802.11j 4.9 GHz band. Each of the structures is studied parametrically in great detail and the antenna prototypes are fabricated on Arlon AD270 substrate. HFSS software is used to simulate and analyze all of the antenna parameters. The simulated and measured results tallied against are found to be in good agreement with each other.     

Modified inverted-L monopole antenna for 2.4/5 GHz dual-band operations

A novel compact modified inverted-L monopole antenna for dual-band operation is proposed. The proposed antenna is designed to operate in 2.4 GHz (2400-2484 MHz) and 5 GHz (5150-5825 MHz) bands for WLAN applications in IEEE 802.11a/b and HIPERLAN/2 systems. The method to realise the desired dual-band operation is by introducing a meandered wire and a conducting triangular section to a conventional inverted-L monopole, which results in a small antenna size of 7/spl times/18 mm/sup 2/. Good impedance bandwidth performance is also observed.     

基于T型谐振器的抗干扰矩形波导缝隙阵列天线设计

介绍了一种抗干扰矩形波导缝隙阵列天线的设计方法,仿真、设计并加工了一款基于T型谐振器的四缝隙矩形波导缝隙阵列天线. 通过在矩形波导下壁引入周期性的T型谐振器,有效提升了天线的抗干扰能力. 测试结果表明,该天线的?10 dB阻抗带宽为10.3%（5.5～6.1 GHz）,增益为11.5～12.8 dBi,天线效率为72.1%～87.3%。与传统矩形波导缝隙阵列天线相比较,本文设计天线在抑制频段 7.9～9.6 GHz的抗干扰能力提升了32.2～69.3 dB,适用于多频段、多任务的无线通信、雷达系统等.     

A miniaturized metamaterial slot antenna for wireless applications

A novel miniaturized five band metamaterial inspired slot antenna is reported. The proposed design consists of a ring monopole and metamaterial Rectangular Complementary Split Ring Resonator (RCSRR) as the radiating part, two L and one T–shaped slot as the ground plane, respectively. Miniaturization in the proposed design is accomplished by metamaterial RCSRR, and also, it helps the antenna to operate at 2.9 and 5.2 GHz frequency bands. The aforementioned miniaturization process leads to about 46.8% reduction in volume of the proposed design, as compared to the conventional antenna. The pass band characteristics of the metamaterial RCSRR through waveguide medium are discussed in detail. In order to enhance the operating abilities of the miniaturized antenna, slots are etched out in the ground plane, thereby making the miniaturized antenna further operate at 2.4, 5.6 and 8.8 GHz, respectively. The proposed design has an active patch area of only , with dB bandwidth of about 4.16% (2.35–2.45 GHz), 5.71% (2.63–2.76 GHz), 10.25% (4.44–4.92 GHz), 6.25% (5.42–5.77 GHz) and 2.39% (8.68–8.89 GHz) in simulation, and about 6.86% (2.25–2.41 GHz), 5.01% (2.55–2.7 GHz), 9.16% (4.58–5.02 GHz), 5.38% (5.79–6.11 GHz) and 5.42% (8.44–8.91 GHz) in measurement. The antenna has good impedance matching, acceptable gain and stable radiation characteristics across the operational bandwidths.     

Bit error rate analysis of Wi-Fi and bluetooth under the interference of 2.45 GHz RFID

IEEE 802.11b WLAN (Wi-Fi) and IEEE 802.15.1 WPAN (bluetooth) are prevalent nowadays, and radio frequency identification (RFID) is an emerging technology which has wider applications. 802.11b occupies unlicensed industrial, scientific and medical (ISM) band (2.4-2.483 5 GHz) and uses direct sequence spread spectrum (DSSS) to alleviate the narrow band interference and fading. Bluetooth is also one user of ISM band and adopts frequency hopping spread spectrum (FHSS) to avoid the mutual interference. RFID can operate on multiple frequency bands, such as 135 KHz, 13.56 MHz and 2.45 GHz. When 2.45 GHz RFID device, which uses FHSS, collocates with 802.11b or bluetooth, the mutual interference is inevitable. Although DSSS and FHSS are applied to mitigate the interference, their performance degradation may be very significant. Therefore, in this article, the impact of 2.45 GHz RFID on 802.11b and bluetooth is investigated. Bit error rate (BER) of 802.11b and bluetooth are analyzed by establishing a mathematical model, and the simula-tion results are compared with the theoretical analysis to justify this mathematical model.     

一种双频双圆极化共面波导馈电缝隙天线

一种新型加载两个开口环形接地导带的双频共面波导（CPW）馈电缝隙天线,被提出来实现双旋向圆极化辐射。从天线信号带伸入槽隙的水平矩形调谐短截线用于改善频带内的阻抗和轴比。对天线进行仿真和实物测量。实验结果表明,该天线的10 dB 回波损耗阻抗带宽分别是,在1.55 GHz 频段为27.69％（1.4~1.85 GHz）,在2.55 GHz频段为26.17％（2.075~2.7 GHz）。在1.55 GHz的频段和2.55 GHz频段所测量的3 dB轴比带宽分别是20.51％（1.4~1.72 GHz）和13.44％（2.36~2.7 GHz）。其辐射极化方向分别是低频段右旋圆极化和高频段左旋圆极化,天线在两频段内的峰值增益分别是3.69 dB和3.81 dB。实物测试结果与仿真结果基本吻合。