The loop antenna is configured on a printed circuit board (PCB) with the dimensions 280 mm × 280 mm. The technology is intended to be simpler and cheaper than other WPANs. To overcome these problems, a new wideband antenna element that is formed by combining a planar dipole antenna and a shorted patch antenna is acquainted. M. Olsson, B. Hagerman, M. Riback, M. Hesse, and B. Niksic, “Field trial results of 4-way receive diversity in a live GSM network,” in Proceedings IEEE 63rd Vehicular Technology Conference (VTC-Spring 2006), Melbourne, Australia, 2747−2751, May 2006. For instance, the HPBW of the antennas in both downlink and uplink significantly affects the power and interference distribution in the network, as mentioned previously. 44. See design antenna efﬁciency, 9–10 antenna geometry broadband monopolar antenna, 117–122 co-planar, 207 single-feed dual-band patch antenna, 122–124 stacked, 207 antenna hopping, 139 Antenna Interface Standards Group (AISG), 77, 78 antenna losses, 3 antenna under test (AUT), 22–23, 80–82 antennas advanced. 6 (November 2002): 1304–1312. Because of the low back radiation, the gain and beamwidth of the antenna are not noticeably changed with frequency, and the gain and efficiency of the antenna are higher than that of many other antenna elements available in the literature. Unlicensed use allowed up to 2 W ERP. The baseband model is ym = K k=1 h k x k m +wm (10.1) with ym being the received vector (of dimension n r, the number of receive antennas) at time m, and h 2, Helsinki, Finland (June 11–14, 2001): 570–574. A MIMO channel with NT transmitting antennas and NR receiving antennas potentially offers NTNR independent fading links. In this way, additional new site locations can be avoided even though a significant capacity increase is achieved. In other words, the amplitude of the backscattering from the tag can be influenced by altering the status of the ASIC, and thus the tag can reflect more or less of the incoming signal in a pattern that encodes the tag’s ID. To avoid a significant increase in the size of the antenna, two slender metal conductors are used. Due to the inherently fine temporal resolution of UWB, arrived multipath components can be 291 292 Chapter Eight sharply timed with a receiver to provide accurate time of arrival (TOA) estimation. Lett., vol. In a GSM system, the system has to handle several simultaneous carriers since the purpose of using active multibeam array antennas is to increase capacity. J. T. Matheney, L. M. Lee, and D. D. Mondul, Apparatus and method for locating objects in a Three-Dimensional Space, US patent No. However, Figure 5.4a shows that peak system capacity in the uplink can be achieved for an HPBW of 60°–90° for the three-sector per cell scheme and 35°–45° for the six-sector per cell scheme, respectively. When the ground plane is smaller than 200 mm × 200 mm, the antenna performance degrades, especially at the lower frequencies in terms of impedance, gain, and AR. Aluminum and galvanized steel with appropriate surface treatments are normally used for the antenna ground plane and casing. Further increasing the ground plane size will only enhance the antenna gain. 5, no. The phase and amplitude of each radiator has to be regulated. In order to achieve stable radiation over the entire operating band, the third approach of using complementary antennas combining an electric dipole and magnetic dipole should be explored. The 13-digit and 10-digit formats both work. The other one method of UWB positioning is to emulate a radar system in which both the range and direction of a UWB tag are mea22 sured by a single base station. Found inside – Page iThis book is written to provide readers with the fundamental concepts ofwireless communications. The configuration of this structure is very simple. We presented the antenna designs, which have been used to enhance the capacity of systems and maximize the usage of transmitted power in cellular phone networks, from an antenna engineering perspective. Similarly, the configuration of the proposed antenna fed by a squarecap is illustrated in Figure 6.24. 7.4.3 Dual-Band Outdoor P2P Antenna Array Figure 7.15 shows a dual-band antenna array operating at both the 2.4 GHz and 5.4−5.9 GHz bands. y z x Conductors Radome (a) Illustration Figure 5.18 Dual-beam antenna with parasitic conductors (b) 194 Chapter Five Without conductors With conductors 90 0 60 120 Normalized directivity [db] −10 −20 30 150 −30 −40 φ = 0 [degree] 180 −30 −20 210 330 −10 0 240 300 270 Figure 5.19 Radiation patterns of dual-beam antenna 5.3.3 SpotCell (Micro-Cell) Antenna In addition to sectors, base stations are often installed in hotspot areas. When the transmitter has no CSI, it divides its power equally among the transmit antennas to form NT independent streams, or Rx= (PT/NT)I. 7.2, that can be achieved is given by the negative of the asymptotic slope of FER for a fixed data rate, plotted as a function of SNR on a log-linear scale. Conf. This antenna system requires one individual transmitter for each antenna element or column as well as phase coherency of the branches on both the receiving and transmitting sides. Antennas Propogat., vol. AP-49, no. A similar set of antennas is used at the Wearable textile multi antenna systems allow a convenient base station to obtain a 4 × 4 MIMO link  with pairs of implementation of wireless off-body MIMO communication dual-polarized antennas on both sides. For some systems, a return loss of less than −15 dB is acceptable. 7.4.7 Three-Element Dual-Band MIMO Antenna S-parameters and correlation, dB Figure 7.27 shows a dual-band (2.4 GHz/5.1−5.9 GHz) MIMO PIFA array arranged in a triangular fashion as well as its impedance, correlation, and radiation performance. Generally, the data rate of a wireless communication link increases with a larger bandwidth, but decreases with mobility. 33. 1 (January 2001): 41–44. 5, (2006): 41−44. Introduction and Overview. Bluetooth provides a way to connect and exchange information between devices such as mobile phones, telephones, laptops, personal computers, printers, global positioning system (GPS) receivers, digital cameras, video game consoles, and so on, over the unlicensed ISM 2.4-GHz band. This allows each frequency band to be tuned independently while retaining impedance matching and radiation performance at both frequency bands. Simulated and measured radiation patterns of the proposed antenna in both E-plane (x-z plane, f = 0°) and H-plane (y-z plane, f = 90°) at 1.37 GHz, 2.17 GHz, and 2.97 GHz are illustrated in Figure 6.12, showing 218 Chapter Six 0 0 330 30 300 60 90 −40 −30 −20 −10 0 270 240 120 150 300 60 90 −40 −30 −20 (a) 1.37 GHz (b) 1.37 GHz 0 0 330 300 −40 −30 −20 330 30 60 −10 0 270 240 120 300 60 90 −40 −30 −20 150 210 0 270 240 210 180 180 (a) 2.17 GHz (b) 2.17 GHz 0 330 300 −40 −30 −20 −10 0 270 240 120 330 30 60 150 −10 120 0 90 270 210 180 30 0 240 150 210 150 −10 120 180 30 90 330 30 210 300 60 90 −40 −30 −20 0 270 240 120 150 210 180 180 (a) 2.97 GHz (b) 2.97 GHz E-plane Co-polar E-plane cross polar −10 H-plane Co-polar H-plane cross polar Figure 6.12 (a) Simulated and (b) measured radiation patterns of the patch antenna fed by a vertical plate pair at different frequencies50 (© 2007 IEEE) New Unidirectional Antennas for Various Wireless Base Stations 219 that the radiation characteristics are stable across the band. 7.1.2 MIMO in WLANs Over the past decade, a wide range of applications has spurred the need to provide a reliable high-speed wireless communication link. The tag’s resulting feedback on the reader antenna brings about the change in the magnetic field. It consists of a planar patch, a ground plane, and a pair of vertical plates connected to the feeding probes of the 50 Ω SMA launchers. Figure 8.24b demonstrates the configuration of the antenna with a bottom-placement metal plate, where a metal plate with dimensions of L2 × W2 is placed at the bottom of the antenna. See advanced antennas ampliﬁer integrated, 168–173 base station. This chapter consists of three parts. The simulated results demonstrate that when the conventional thin dipole, as presented in Figure 6.18a, is modified to become a planar dipole (Figure 6.18b), the radiation pattern does not change much. Chichester: John Wiley & Sons, 2004. BS P2P antennas typically have high gain (> 12 dBi) and narrow beamwidth (< 40°) in both the E- and H-planes. The former is used to enable the worldwide deployment of multivendor interoperable mobile broadband wireless access networks, whereas the latter is aimed at constructing wireless regional area networks (WRANs), utilizing channels that are not employed within the already allocated television frequency spectrum. The undesirable beam-squinting and cross-polarization increase as the array becomes larger in size. Coverage includes the most popular applications in WWAN (GSM, CDMA, and WCDMA), WLAN (Bluetooth and WiFi), WMAN (WiMAX), and WPAN (UWB and RFID).Antennas for Base Stations in Wireless Communications presents a full picture of modern base station antenna technology--from fundamentals and parameters to engineering and advanced solutions--and highlights new technologies in antenna design with enhanced performance. The dimension of the square loop antenna is 250 mm × 250 mm, and the width of the trace is 10 mm. 52 (January 2004): 98–105. The dimensions of the metal plates are indicated as (L3, W3) and (L4, W4), respectively. The antennas of a cellular base station are the source of radiofrequency radiation that is transmitted through the spatial volume of the . R. G. Vaughan, “Polarization diversity in mobile communications,” IEEE Trans. Obviously, the measured cross-polarization levels are around 20 dB less than the co-polarization levels. Lett., vol. 952−955 MHz available for unlicensed use at 20 mW EIRP. However, the shaped beam pattern using the operative method is similar to a cosecant beam. An amplifier integrated sector antenna with both power amplifiers and low-noise amplifiers integrated in the antenna unit is shown in Figure 4.28. 10. However, an RFID system with a high gain antenna may conflict with EIRP regulations. 11 (November 2006): 3302−3316. The copper sections from the wire-cuts can be bent inward, which will act as the feeding strip and the shorting strip, each measuring 3 mm × 4 mm and separated by 6 mm. V. Rathi, G. Kumar, and K. P. Ray, “Improved Coupling for Aperture Coupled Microstrip Antennas,” IEEE Transactions on Antennas and Propagation, vol. 6,483,461, November 2002. Therefore, a consistent gain profile and 3-dB beamwidth, as well as low cross-polarization, can be achieved across the broad bandwidth. The HPBW of two four- and sixteen-element antennas are 39.8°/25.7° in E-planes and 36.4°/21.5° in H-planes, respectively. Found insideThis is an IEEE classic reissue of the book published by John Wiley & Sons in 1974.This definitive text and reference covers all aspects of microwave mobile systems design. A sectored antenna array is used for transmitting/receiving UWB signals; the main beam of the directional antenna elements is aligned at different directions; and a 360° circumference can be covered by using multiple antenna elements. The cylinder is 0.64(= 0.9/1.4) of the flat plate value.11,12 Cylindrical radomes are, therefore, more commonly used. As expected, the antenna with the larger ground plane has superior performance over the antennas with smaller ones. The antenna array is arranged such that the pointed edge of the reflector is aligned behind and along the midpoint of each antenna element. The Internal Telecommunication Union (ITU) is an international body where governments and the private sector work together on issues pertinent to telecommunication networks. Subsequently, system capacity can be increased by suppressing the interference among the adjacent sectors. If the antenna has a very narrow bandwidth due to a very high Q, the signals in the sidebands may be cut off. K = 0 corresponds to a Rayleigh channel and K = ∞ corresponds to a nonfading channel. Each subarray fed by one phase shifter has four array elements fed in-phase. It was observed in the mid 1990s that a similar effect can occur for a point-to-point channel with multiple transmit and receive antennas, i.e., even when the transmit antennas are not geographically far apart. I don't know how anyone can rate this book 5-star (or even 2-star for that matter). The frequency shift of the antennas with the different metal plate placements can be predicted by calculating the variation in antenna inductance. 16. As a result, we can conclude the antenna gain is very stable across the operating bandwidth for the L-strip coupled feed. 6.3.3 Complementary Antennas with a Slot Antenna and a Conical Monopole In addition to the slot-dipole antenna, some have proposed slot-monopole antennas52–53 for realizing similar E- and H-plane patterns. This book provides a solid grounding in antennas and propagation, covering terrestrial and satellite radio systems in both mobile and fixed contexts. Increasing the number of transceivers and improving the quality in the network in both the target cells equipped with multibeam antennas and surrounding cells using sector antennas are possible. The L-plate is suspended above the ground plane and positioned in a way such that the geometry has symmetry about the x-axis. Antennas for WLAN (WiFi) Applications 247 E. Cables and Connectors Low-cost coaxial cables such as the RG-58/U (50 Ω), RG-178/U (50 Ω), and RG-59/U (75 Ω) are commonly used to connect the antenna and the radio. In 1984, NTT achieved countrywide service in Japan. The UWB signal adopted in 802.15.4a uses two frequency bands within the range of frequencies available by the regulation of the FCC: a lower band across 3.1−4.8 GHz and an upper band across 6.2−9.7 GHz, which is illustrated in Figure 8.10. Found insideIn addition to antenna topics, the handbook also covers modern technologies such as metamaterials, microelectromechanical systems (MEMS), frequency selective surfaces (FSS), and radar cross sections (RCS) and their applications to antennas, ... Found insideThe book will help the readers, in particular wireless communication researchers, to have wider futuristic and innovative visions for the advances in the field. The IMT2000 operates in the 2-GHz band. Table 5.1 shows the change in HPBW in 800-MHz, 1.5-GHz, and 2-GHz bands. To illustrate the performance gains possible, the paper describes research being conducted by . 234 Chapter Six The measured and simulated SWRs of the square-cap coupled fed case are shown in Figure 6.30. LBT New regulations should be in place shortly. However, a RFID system using such an antenna configuration cannot receive the signal at the designated frequency of 13.56 MHz since the antenna is no longer well-matched at 13.56 MHz; hence, the reading range will be greatly reduced. 409 (January 2001): 316–318. Y. Yamaguchi and Y. Ebine, “Design of a base station antenna with 60 degrees beam-width in the horizontal plane for cellular mobile radios,” IEICE, vol. A significant effect on the AR is observed. The 802.15.4a physical layer is based on two different technologies: UWB and chirp signals. In its basic mode, the modulation is Bluetooth 294 Chapter Eight Gaussian frequency shift keying (GFSK). Metallic environments severely affect the performance of the HF loop antenna by detuning the resonant frequency and reducing the magnetic field intensity.27 Figure 8.24 depicts the configuration of the loop antenna with typical metal environments in practical applications. The higher return loss for Antenna P3 is due to the presence of the 2.4-GHz antenna P4. The standard for the chirp signals defines that 14 channels spaced at 5 MHz are in the frequency range between 2410 and 2486 MHz. The second part will focus on discussing RFID reader antennas. Because additional insulation resistance of the capacitor contributes to achieving an adequate Q factor, the extra resistor is not needed. The case study in this part demonstrates RFID reader antenna designs at high frequency (HF, 13.56 MHz) and ultrahigh frequency (UHF, 840−960 MHz). In addition to an antenna’s electrical performance, other factors are also vital for a successful design. K. F. Lee, K. M. Luk, K. F. Tong, S. M. Shum, T. Huynh, and R. Q. Lee, “Experimental and simulation studies of the coaxially fed U-slot rectangular patch antenna, “ IEE Proc.-Microw. 9. "Professor Andreas F. Molisch, renowned researcher and educator, has put together the comprehensive book, Wireless Communications. See broadband antennas capacity solutions, 130–131 ceiling-mounted, 96, 97 circularly polarized, 317 coaxial, 68 complementary, 206, 219–236 considerations, 1, 28 cost considerations, 68 CP, 327–340 cylindrical array, 161 deﬁned, 1 design of. Figure 5.27 shows a base station antenna array with a remote electric phase-tilt control box. A relatively evenly distributed power is achieved by using this hybrid series- and corporate-feeding network, which ensures that most of the elements are radiating in-phase across a broad frequency band. 34. 20 (August 2002): 1227–1239. The dipole is designed to operate in the 1.5 GHz band. See patch antennas performance, 1–14 planar dipoles, 20–21 planar inverted-L/F, 18–20 planar monopole, 20–21 reader, 296–300, 313–318, 321–327 RET, 77, 83, 84 RFID reader, 296–300, 313–318, 321 sector, 148 semi-smart, 78, 92 single-beam, 188–189 slim, 184–187 slot, 221–222 smart, 78, 79, 92 suspended plate, 17–18 system calibration, 28, 196 triple-band HPBW, 190–192 triple-band slim, 186–187 types of, 1, 15–21 UHF/MWF, 327–340 unidirectional. Commun., vol. AP-39, no. 7.3.3 Indoor Point-to-Multiple Point Antennas Indoor P2MP antennas require a broad beamwidth for maximum coverage. The 2.4-GHz antennas exhibit a higher correlation between P4/P8 compared to P8/P12 within the 2.4−2.5-GHz band, which is due to the higher mutual coupling between them. Learn how we and our ad partner Google, collect and use data. 3. The performances of the two prototypes are measured by an HP8510-C Network Analyzer, a compact range with ORBIT/FR MiDAS Far-Field Antenna Measurement and Analysis System. 38. It is difficult to ensure an equi-amplitude and in-phase signal distribution to all the radiators across a broad bandwidth. 2 Base Station Background The intent of this section is to explore the role of base stations in communications systems, and to develop a reference model that can be used to describe and compare base station software architectures. 55, no. For discussion of the LTE standard the abbreviation eNB for evolved node B is widely used. Use up to 4W ERP allowed under license. Polypropylene is commonly used in injection molding, but is susceptible to marring or chalking after prolonged UV irradiation. This page intentionally left blank Chapter 7 Antennas for WLAN (WiFi) Applications Zhi Ning Chen, Wee Kian Toh, Shie Ping See, Xianming Qing Institute for Infocomm Research 7.1 Introduction 7.1.1 WLAN (WiFi) Wireless Local Area Networks (WLANs) provide wireless network communications, in particular, between computers and other portable devices with fixed access points over a short distance, typically in the order of tens of meters. Find many great new & used options and get the best deals for Antennas for Base Stations in Wireless Communications at the best online prices at eBay! 34 (1998): 2292–2293. This is especially challenging in an indoor wireless environment, where transmitted signals are received through multiple paths, which may add up destructively at the receiver, resulting in serious degradation in the overall system performance.
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