Novel Wideband Directional Dipole Antenna on a Mushroom Like EBG Structure

A new method to design thin wideband directional dipole antennas on electromagnetic bandgap (EBG) structure is introduced. At the heart of this method is the idea to understand and properly utilize the complex interactions between the dipole impedance and the EBG reflection phase characteristics. Using the proposed technique a thin wideband printed dipole is designed, fabricated and tested. The antenna can satisfy applications, such as Digital Communication System (DCS, 1.71-1.88 GHz), Global System for Mobile Communication (GSM, 1.85-1.99 GHz), Personal Communication System (PCS, 1.85-2.05 GHz), Universal Mobile Telecommunication System (UMTS, 1.92-2.17 GHz) and Wireless Local Area Network (WLAN, 2.4-2.485 GHz) within VSWR les 2.5:1. Antenna peak gain varies from 5.5 to 8.3 dBi from 1700 to 2500 MHz while the front to back (F/B) ratio is higher than 15 dB for an overall antenna size of 102 mm by 76.4 mm by 5.9 mm.     

Octa-band internal monopole antenna for mobile phone applications

A low-profile monopole antenna covering the following frequency bands is proposed for mobile phone applications: Global System for Mobile Communications (GSM-900), Digital Communication System (DCS), Personal Communication Services (PCS), Universal Mobile Telecommunications System (UMTS), Wireless Broadband (WiBro), Bluetooth, Satellite-Digital Multimedia Broadcasting (S-DMB), and Wireless Local Area Network (WLAN) frequency bands in the 5.0 GHz range. Multiple resonators in a compact configuration have been used to realise the octa-band internal antenna within a volume of 2.08 cm³ that is very attractive for multifunctional slim handsets. Measured performances of a prototype antenna have been compared to predicted results.     

Compact PIFA for Mobile Terminals Supporting Multiple Cellular and Non-Cellular Standards

A novel multiband planar inverted-F antenna (PIFA) covering ten frequency bands has been proposed for personal wireless communications terminals. The design is based on the combination of various techniques that are used for designing multiband/broadband antennas. We used a shorted parasitic patch efficiently coupled to the driven patch, a quarter-wave resonator connected to the feed strip in parallel with the main patch, and four slits in the main radiator to excite various current modes in the antenna structure. The antenna is designed within a volume of 4.0 times 2.0 times 0.8 cm³ and it can be used to serve the following wireless communication systems: Global System for Mobile Communications (GSM-900), Digital Communications System (DCS), Personal Communication Service (PCS), Universal Mobile Telecommunications System (UMTS), WiBro at 2.35 GHz, Bluetooth, Satellite-Digital Multimedia Broadcasting (SDM-B) at 2.65 GHz, WiMAX at 3.5 GHz, and the two bands (5.15-5.35 GHz and 5.725-5.875 GHz) for the wireless Local Area Network (WLAN) standards. A prototype antenna was fabricated and tested for input reflection coefficient and radiation performances. The measured and simulated results have been presented and discussed. Important geometrical parameters determining the multiband performances of the antenna have been explained in the paper.     

Transparent and conformal wheel-shaped fractal antenna for vehicular communication applications

In this article, a low cost, compact conformal antenna is proposed for vehicular communications applications. The concept of fractal geometry is applied in this design to make the model more attractive in its appearance as well as to attain desired bands in the vehicular communication spectrum. It is fabricated on a transparent and flexible poly vinyl chloride material of size 55 mm × 40 mm × 3 mm. The proposed antenna is intended to operate in GSM-1800/1900, Digital Communication System (DCS-1800), Personal Communication Service (PCS-1900), Universal Mobile Telecommunications System (UMTS), Long-Term Evolution (LTE2600), Industrial, Scientific, and Medical radio band (ISM 2.4G), Wireless local area network (WLAN), Bluetooth, World Interoperability for Microwave Access (WiMAX), IEEE802.11p protocol based Vehicle-to-everything, Dedicated short-range communications (DSRC) and Wireless Access in Vehicular Environments (WAVE) communications bands. The prototype of the antenna in its planar and conformal versions exhibit the wideband characteristics and their measured results show good agreement with that of obtained simulation results. The virtual analysis of platform mounted characteristics of the proposed antenna at two different locations of the vehicle (vehicle roof-top and on side-view mirror) are performed in ANSYS Savant simulation tool and the corresponding far-field radiation performance is characterized.     

Internal Patch Antenna With a Thin Air-Layer Substrate for GSM/DCS Operation in a PDA Phone

A thin dual-band internal patch antenna for Global System for Mobile Communication, 890-960 MHz/Digital Communication System, 1710-1880 MHz (GSM/DCS) operation in a Personal Digital Assistant (PDA) phone is presented. The antenna can generate two wide resonant modes for GSM (890-960 MHz) and DCS (1710-1880 MHz) operation, yet it requires an air-layer substrate of thickness 4 mm only, which is among the thinnest internal mobile phone antennas that have been reported. The antenna's top patch comprises a resonant narrow strip supporting a longer resonant path for GSM operation and a resonant subpatch supporting a shorter resonant path for DCS operation. By including a suitable widened end portion for the narrow strip and a suitable tapered end portion for the subpatch, increased bandwidths for the proposed thin internal mobile phone antenna are obtained. Detailed design considerations of the proposed antenna are described. In addition, the user's hand effects on the performances of the proposed antenna are studied     

Multiband monopole antenna loaded with Complementary Split Ring Resonator and C-shaped slots

This paper presents a compact semi circular monopole antenna loaded with Complementary Split Ring Resonator (CSRR) and two C-shaped slots is proposed for Global System for Mobile Communication (GSM), Worldwide Interoperability for Microwave Access (WiMAX) and C-band applications. The size of the proposed antenna is 20 × 20 × 0.5 mm³. The resonance frequency of WiMAX (3.73 GHz) is achieved by introducing CSRR slots on the ground plane. To realize multiband characteristics for GSM (1.77 GHz), WiMAX (2.6 GHz) and C-band (4.15 GHz), two C-shaped slots of quarter wavelength are introduced in radiating element. The extraction procedure of negative permittivity for the proposed CSRR is discussed in detail. The proposed antenna is fabricated and measured. Simulated and measured results are in good agreement. Omni directional radiation pattern is obtained in H-plane and bi directional radiation pattern is obtained in E-plane. Parametric study of CSRR and C-shaped slot are examined to obtain best results. The proposed antenna has significant advantages, including low profile, miniaturization ability, and good impedance matching.     

一种槽耦合的双频双极化微带天线

设计了一种适用于基站天线的双频双极化微带天线单元,该天线单元采用槽耦合、多层贴片和对称馈电的结构形式。用商业软件Ansoft对天线的电特性进行仿真计算,制作了实验模型,测试结果优于仿真结果。天线在880-960MHz的GSM（全球移动通信系统）频段和1710～1880MHz的DCS（数字蜂窝系统）频段上的反射损耗均大于10dB,在两个频段上极化互相垂直的两个端口的隔离度均大于24dB。     

加载新型复合左右手传输线单元的宽带单极子天线设计

提出了一种新颖的一维复合左右手传输线(CRLH-TL)单元,并将其加载到传统微带馈电的单极子天线上,设计出一种宽带的变形单极子天线。该宽带天线工作在1.67~2.67GHz,相对带宽达到了46%,有效地覆盖了DCS(Digital Cellular System,1710~1880MHz)、PCS(Personal Communication Service,1850~1990MHz)、Wi-Fi(Wireless Fldelity,2400~2480MHz)等多个通信频段。首先,利用CRLH-TL的相位补偿效应,结合传统单极子天线的自身谐振,得到多个谐振工作频点;然后,通过参数优化,使得其中的两个工作频点相互靠近形成一个更宽的工作频段,并且在工作频段内获得了较好的增益和稳定的方向图。最后,对所设计的天线进行实物加工并测试,测试结果与仿真结果吻合良好。     

An Adaptive Digital Front-End for Multimode Wireless Receivers

The ongoing evolution from 2G to 3G and beyond requires multimode operation of wireless cellular transceivers. This paper discusses the design of an adaptive wireless receiver for multimode operation and power efficiency. This is achieved by sharing digital signal processing stages for all operation modes and adapting them such that performance requirements are met at a minimum power consumption. The flexibility a digital front-end introduces in combination with an analog zero-intermediate-frequency receiver is studied with respect to the main cellular communication standards (Global System for Mobile Communication, Enhanced Data Rates for Global Evolution, Wide-Band Code-Division Multiple Access (WCDMA)/High-Speed Downlink Packet Access, and CDMA2000 and satellite navigation systems (Galileo), with considerations of impacts on the capability of an implementation of a software-defined radio. The proposed approach is verified by simulations exhibiting an error-vector magnitude of 2.9% in Universal Mobile Telecommunications System mode while the estimated power consumption can be reduced by 62% versus full featured mode at reasonable degradation in modulation quality.     

Offset-fed complementary split ring resonators loaded monopole antenna for multiband operations

A miniaturized multiband monopole antenna based on rectangular-shaped Complementary Split Ring Resonators (CSRRs) with offset-fed microstrip line is proposed for Global System for Mobile Communication (GSM) and Wireless Local Area Network (WLAN) applications. The proposed antenna is fabricated on a FR-4 substrate having a dielectric constant (ɛ_r) of 4.4 within a small size of 19.18 × 22.64 × 1.6 mm³. CSRRs in the monopole antenna create a multiband characteristics and bandwidth improvement, which is analyzed by use of the precise quasi-static design equations and electromagnetic simulation software (HFSS version 13). By selecting a proper offset-fed microstrip line, it is capable to achieve 50 Ω characteristic impedance and good impedance matching. The parameter extraction procedure of the metamaterial property of the CSRRs is enlightened in detail, by which the negative permittivity existence and the new resonance frequencies are verified. Simulated and measured result coincides with each other. The measured H-Plane (azimuthal plane) exhibits omnidirectional radiation pattern and E-plane (elevation plane) shows a dipole like bidirectional radiation pattern. The proposed antenna has adequate advantages, including simple design, small size, lower return loss and capable of multiband operations.     

A Survey on Media Independent Handover (MIH) and IP Multimedia Subsystem (IMS) in Heterogeneous Wireless Networks

One challenge of wireless networks integration is to provide ubiquitous wireless access abilities and seamless handover for mobile communication devices between different types of technologies (3GPP and non-3GPP), such as Global System for Mobile Communication, Wireless Fidelity, Worldwide Interoperability for Microwave Access, Universal Mobile Telecommunications System and Long Term Evolution. This challenge is critical as mobile users are becoming increasingly demanding for services regardless of the technological complexities associated with them. To fulfil these requirements for seamless vertical handover (VHO) two main interworking frameworks have been proposed by IEEE Group and 3GPP for integration between the aforementioned technologies; namely, Media Independent Handover IEEE 802.21 and IP Multimedia Subsystem, where each of them requires mobility management protocol to complement its work, such as Mobile IP and Session Initiation Protocol, respectively. Various VHO approaches have been proposed in the literature based on these frameworks. In this paper, we survey the VHO approaches proposed in the literature and classify them into four categories based on these frameworks for which we present their objectives and performances issues.     

一种新型毫米波磁电偶极子天线阵列设计

该文将磁电偶极子天线作为辐射阵子,并应用一种共面波导馈电网络,研究并设计了一种新型44毫米波天线阵列。这种设计不仅具有很宽的阻抗带宽和增益带宽,而且价格低廉易于生产。仿真和测试结果表明,此天线阵列的相对阻抗带宽为54.5%, 3 dB增益带宽为37.1%,在工作频带内(40.2~70.0 GHz),最大增益为18.1 dBi。而基于其他技术设计的44毫米波天线阵列(如微带天线、偶极子天线)工作频带宽度一般在20%左右,增益一般在16~17 dBi。所以该文提出的天线阵列设计具有明显的优势。另外,仿真设计结果和实测的电参数数据有较好的一致性。     

馈源阵面排列对偏置多波束天线特性的影响

以３７单元馈源阵为例,就用于卫星移动通信系统中的偏置多波束天线进行分析探讨：在原有两种馈源阵阵面排列形式的基础上,又提出了第三种排列形式,即馈源阵的球面排列形式,并对这三种形式下偏置多波束天线的远场特征进行了计算比较,得出了一些有益的结论;另外,将馈源阵阵面适当地偏离焦点也可使多波束天线的远场特性得以改善。     

一种宽带WLAN贴片天线

文中提出了一种单馈的宽带贴片天线应用于无线局域网络通信。该天线由方形贴片、电抗性阻抗表面以及电磁带隙结构组成。文中提出同时加载电抗性阻抗表面和电磁带隙结构能够实现小型化以及宽带化。电抗性阻抗表面作为接地平面能够降低天线的谐振频率。电磁带隙结构能够提高天线的阻抗带宽。测试结果表明所提出的WLAN贴片天线的相对带宽为22.3%(S₁₁=-10 dB),覆盖4.77～5.97 GHz,可以获得6.3～7.2 dBi增益。与现有宽带小型化天线相比,该天线在保证宽带小型化的前提下仍具有较高增益,且辐射性能具有较高的一致性,十分有利于其应用。该天线能够覆盖IEEE 802.11a标准所规定的5 GHz频段,能够实现无线局域网之间的高速数传。     

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.     

新型低剖面阿基米德螺旋天线设计

设计了一款低输入阻抗的阿基米德螺旋天线。在传统阿基米德螺旋天线的始端加入宽度一定的指数螺蜷线,天线的输入阻抗得到降低,从而放松了对指数渐变微带线馈电巴仑的长度要求。该天线的输入阻抗为75Ω,这使得指数渐变微带巴仑的长度仅为22.5mm即可充分满足天线在2～10GHz频率范围内的馈电要求。天线采用深度为22.5mm(约为最大工作波长的15%)的反射背腔,测试结果表明:在2～10GHz的频率范围内,天线驻波比小于2.5,天线主辐射方向上的轴比小于4dB,方向图对称性良好。     

一种超高频射频识别读写器天线

本文提出了一种适用于我国UHF RFID读写器的宽带圆极化叠层微带天线,通过选用廉价FR4板、空气层介质和对角线切角的正方形贴片组成叠层结构,采用S型水平蜿蜒带条激励主辐射贴片的馈电方式,展宽了天线的阻抗带宽和轴比带宽.所提出的S型水平蜿蜒带条馈电技术,实现了对称的辐射方向性图.给出了天线设计思路,并利用电磁仿真软件分...     

UMTS overview

The Universal Mobile Telecommunications System (UMTS) as specified by the Third Generation Partnership Project (3GPP) was formally adopted by the ITU as a member of its family of IMT-2000 Third Generation Mobile Communication standards in November 1999. This paper provides some background to the UMTS standard and an overview of the system architecture. Some information about the current status of technology trials is provided as well as predictions for the services that future UMTS networks are likely to deliver to the end user     

Multiband Microstrip-Fed Right Angle Slot Antenna Design for Wireless Communication Systems

This paper presents a novel multiband microstrip-fed right angle slot antenna design technique for multiple independent frequency bands. The new technique uses various slot sizes at various appropriate positions. We first propose a tri-band slot antenna consisting of three right angle slots. Then, a quad-band slot antenna is developed with four right angle slots which achieves slant ±45° linear polarization, omnidirectional pattern coverage, good antenna gain, and acceptable impedance bandwidths over all the operating frequency range. Moreover, an open-circuited tuning stub is introduced to achieve good impedance matching. Both proposed antennas are designed on a ground plane of RT/duroid 5880 substrate with a thickness of 1.575 mm. The real measurable results show that the desired frequencies used in wireless communication systems, namely, WLAN and WiMax, are efficiently achieved.     

Fractal based ultra-wideband antenna development for wireless personal area communication applications

This paper presents a bandwidth enhanced, compact planar ultra-wideband antenna design for wireless personal area communication (WPAN) applications. The proposed antenna has fractal based geometry and is constructed using several iterations of a pentagon slot inside a circular metallic structure. The partial ground plane of the basic radiator is tapered, defected and a U slit is etched out from the microstrip feed to improve the −10 dB |S11| bandwidth. The proposed fractal based antenna has an impedance bandwidth from 2.9 GHz to 15 GHz with low profile configuration and is fabricated on FR4 substrate with dimensions of 32 mm × 32 mm × 1.6 mm. To authenticate the designed prototype, the antenna is fabricated and tested for impedance and radiation characteristics. The designed antenna has stable radiation characteristics in the operating band. Furthermore, the antenna is validated for its applicability in WPAN, by calculating fidelity factor through time domain analysis along with the transmission coefficient and group delay measurements.