Introduction Over the past two decades,developments in very large-scale integra- tion (VLSI)or ultra large-scale integration (ULSI)technologies for and lithium batteres hav been revolutionary.In parallel,huge progress has been made in the felds of computer and information theory.These innovations are the ingredients,in terms of both hardware and software,for the rapid growth of modern mobile hvea requirem tsand strong demands in the applicati rket.This book presents the latest advances in antenna technologies for a variety of base stations in mobile wireless communication systems. Mobile Wireless Communications and Antenna Technologies The development of the cellular mobile phone is an excellent example of a modern mobile wireless communication technology.Modern per- sonal mobile wireless communications started with the first commercial mobile phone network-the Autoradiopuhelin(ARP),designated as the zero eration (OG)cellular -launched in Finland in 1971. seve al commercial trials of cellular netwo rks were carried out in the United States before the Japanese launched the first success. ful commercial cellular network in Tokyo in 1979.Throughout the 1980s. mobile cellular phones were progressively introduced in commercial operations.At that time,the cellular network consisted of many base stations located in a relatively small num r of cells that covered the service areas.Within the network and by using efficient protocols,auto mated handover between two adjacent cells could be achieved seamlessly when a mobile phone was moved from one cell to another.All the cellular systems were based on analog transmissions.Due to low-degree inte- 够
xvii Introduction Over the past two decades, developments in very large-scale integration (VLSI) or ultra large-scale integration (ULSI) technologies for electronic circuits and lithium batteries have been revolutionary. In parallel, huge progress has been made in the fields of computer science and information theory. These innovations are the ingredients, in terms of both hardware and software, for the rapid growth of modern mobile communication systems, networks, and services. As antenna engineers, we have been challenged by the extremely fast changes in technical requirements and strong demands in the application market. This book presents the latest advances in antenna technologies for a variety of base stations in mobile wireless communication systems. Mobile Wireless Communications and Antenna Technologies The development of the cellular mobile phone is an excellent example of a modern mobile wireless communication technology. Modern personal mobile wireless communications started with the first commercial mobile phone network—the Autoradiopuhelin (ARP), designated as the zero generation (0G) cellular network—launched in Finland in 1971. After that, several commercial trials of cellular networks were carried out in the United States before the Japanese launched the first successful commercial cellular network in Tokyo in 1979. Throughout the 1980s, mobile cellular phones were progressively introduced in commercial operations. At that time, the cellular network consisted of many base stations located in a relatively small number of cells that covered the service areas. Within the network and by using efficient protocols, automated handover between two adjacent cells could be achieved seamlessly when a mobile phone was moved from one cell to another. All the cellular systems were based on analog transmissions. Due to low-degree integration and high-power consuming circuits as well as bulky batteries, mobile phones at that time were too large to carry until Motorola, Inc
xvili Introduction introduced the first portable mobile phone.Later,analog systems kn ne systems,were acceptec as true personal mo In the 1990s,digital technology was employed for the development of mobile phone systems,which were rapidly advancing and quickly replacing the analog systems to become the second generation(2G)per sonal mobile phone systems.Benefiting from the hu e progre en in integrated circ s (IC) and batteries as wel as the deployment of mor base stations,the bricks(mobile phones)shrunk to become actual hand held devices.Meanwhile,cellular networks began to provide users with additional new services such as text messaging(short message service or SMS)and media content such as downloadable ring tones After the cess of the 2G cellular network,extended 2Gsystems such as the CDMA2000 1xRTT and GPRS featuring multiple access technology,were developed to enhance network performance and pro- vide significant economic advantages.These systems are known as the 2.5 generation (2.5G).In theory,the 2.5G CDMA2000 1xRTT network can achieve the maximum data rate of up to 307 kbps for delivering voice,data,and si maling data (QoS).With so many different standards,however,different technolo gies had to be developed.To achieve a worldwide standard,the third Telcmunicati i rr ue200. with a set of technical sp ecifications suchasa2-Mbps maximu rate for indoors and 384-kbps maximum data rate for outdoors,although this process did not standardize the technology itself.The first commer- cial 3G CDMA-based network was launched by NTT DoCoMo in Japan on October 1,2001.Following this,many 3G networks have been set up worldwide.By the end of 2008,global subscriptions to 3G networks exceeded 300 million.For exa mple,in China al the number of sub scribers had reached 118 million by the end of 2008 After the 3G systems,the market is looking toward the next-generation systems,which will be the fourth generation(4G)or beyond 3G(B3G). The development of the 4G systems targets QoS and increasingly high data rates to meet the requi ents of future applications such as less br multime a me ssaging ser vice (MMS),video chat mobile TV,high-definition TV(HDTV)content,digital video broadcast- ing (DVB-T/H),and so on. Before the 4G systems are realized,however,many B3G systems are being developed.For example,the 3GPP Long Term Evolution(LTE),an ration Partnership Project,is (UMTS)in terms of spectral efficiency,costs,service quality,spectrum usage,and integration with other open standards
introduced the first portable mobile phone.1 Later, analog systems, known as the first generation (1G) mobile phone systems, were accepted as true personal mobile wireless communication systems. In the 1990s, digital technology was employed for the development of mobile phone systems, which were rapidly advancing and quickly replacing the analog systems to become the second generation (2G) personal mobile phone systems. Benefiting from the huge progress seen in integrated circuits (IC) and batteries as well as the deployment of more base stations, the bricks (mobile phones) shrunk to become actual handheld devices. Meanwhile, cellular networks began to provide users with additional new services such as text messaging (short message service or SMS) and media content such as downloadable ring tones. After the success of the 2G cellular network, extended 2G systems, such as the CDMA2000 1xRTT and GPRS featuring multiple access technology, were developed to enhance network performance and provide significant economic advantages. These systems are known as the 2.5 generation (2.5G). In theory, the 2.5G CDMA2000 1xRTT network can achieve the maximum data rate of up to 307 kbps for delivering voice, data, and signaling data. The 2G and/or 2.5G networks provided users with quality of service (QoS). With so many different standards, however, different technologies had to be developed. To achieve a worldwide standard, the third generation (3G) systems have been standardized in the International Telecommunication Union (ITU) family of standards, or the IMT-2000, with a set of technical specifications such as a 2-Mbps maximum data rate for indoors and 384-kbps maximum data rate for outdoors, although this process did not standardize the technology itself. The first commercial 3G CDMA-based network was launched by NTT DoCoMo in Japan on October 1, 2001. Following this, many 3G networks have been set up worldwide. By the end of 2008, global subscriptions to 3G networks exceeded 300 million. For example, in China alone, the number of subscribers had reached 118 million by the end of 2008. After the 3G systems, the market is looking toward the next-generation systems, which will be the fourth generation (4G) or beyond 3G (B3G). The development of the 4G systems targets QoS and increasingly high data rates to meet the requirements of future applications such as wireless broadband access, multimedia messaging service (MMS), video chat, mobile TV, high-definition TV (HDTV) content, digital video broadcasting (DVB-T/H), and so on. Before the 4G systems are realized, however, many B3G systems are being developed. For example, the 3GPP Long Term Evolution (LTE), an ambitious project called the “Third Generation Partnership Project,” is designed to improve the Universal Mobile Telecommunications System (UMTS) in terms of spectral efficiency, costs, service quality, spectrum usage, and integration with other open standards. xviii Introduction
Introduction xix WiMAX WiFI UWB,ZigBee NEC WPAN(Wireless personal area network) WLAN(Wireless local area network) WMAN(Wireless metropolitan area network) WWAN(Wireless wide area network) Figure 1 Coverage of modern personal wireless networks Our lifestyle has changed significantly compared to 20 years ago Besides the proliferation of mobile phones,wireless communication technologies have penetrated many aspects of life from business to social networks to healthcare and medical applications.A variety of wireless communication systems are now available to connect almost all people and premises,as shown in Figure 1. In these systems,antennas play a vital role as one of the key compo- nents or subsystems.The rapid spurred strong d mands fo proposal of new applications hasals r new h igh-performance antennas.Although the fundamental physical principles of antennas have not changed. antenna engineers have been experiencing the rapid advancement of antenna technologies.For example,antenna technologies for the ter- minals and base stations in mobile communications have changed remarkably since the first mobile phon which had long whip anten nas,appeared in Conventionally,an antenna or array is designed as a radiating RF component.By optimizing the radiators'shapes or configurations,or by combining different radiating elements,the antenna or array will achieve the performance needed to meet system requirements.Such a methodology has been used for a long time in the design of commercial
Our lifestyle has changed significantly compared to 20 years ago. Besides the proliferation of mobile phones, wireless communication technologies have penetrated many aspects of life from business to social networks to healthcare and medical applications. A variety of wireless communication systems are now available to connect almost all people and premises, as shown in Figure 1. In these systems, antennas play a vital role as one of the key components or subsystems. The rapid proposal of new applications has also spurred strong demands for new high-performance antennas. Although the fundamental physical principles of antennas have not changed, antenna engineers have been experiencing the rapid advancement of antenna technologies. For example, antenna technologies for the terminals and base stations in mobile communications have changed remarkably since the first mobile phones, which had long whip antennas, appeared in the market, as detailed in Table 1. Conventionally, an antenna or array is designed as a radiating RF component. By optimizing the radiators’ shapes or configurations, or by combining different radiating elements, the antenna or array will achieve the performance needed to meet system requirements. Such a methodology has been used for a long time in the design of commercial Introduction xix Figure 1 Coverage of modern personal wireless networks UWB, ZigBee Bluetooth RFID NFC WiFi WiMAX GSM, CDMA, GPRS, EDGE, UMTS, HSDPA/HSUPA, LTE WPAN (Wireless personal area network) WLAN (Wireless local area network) WMAN (Wireless metropolitan area network) WWAN (Wireless wide area network)
xx Introduction TABLE1 Features of Antennas in Personal Mobile Terminals and Base Stations Antennas in Mobile Antennas/Arrays Terminals in Base Stations Size Very small Compact Operating bands Multiple bands(up to six)for Multiple bands( to four cell phones and laptops for cell phones.WiFi.and Bluetooth Ultra-wideband Universal UHF bands for RFID Ultra-wideband Diversity ea部e Available if needed Polarization Circularly polarized in Dual polarization for cell RFID handheld readers phones.WiFi.and bluetooth Circular polarization in Deteandlain Adaptive beamforming Not available Available if needed MIMO Will be available Available if needed mobile terminal antennas where critical size and cost constraints are imposed.For base stations,the requirements for high-performance antennas or arrays have pushed antenna engineers to implement more complicated RF,electrical,and/or mechanical designs to control antenna and array performance,in particular for the radiation patterns of base station antennas or array ys.Therefore,the antenna or array is designed as a subsystem rather than only an RF omponent Furthermore,the antenna or array will be intelligent(smart or adap. tive)if powerful signal processing functions are applied to controlling antenna performance or digitally processing signals from antennas to form a closed feedback loop.The concept of antenna design is,therefore expanded to ver not only RF radiators,controlling ci tems but also signal proces ingalgorithms.as shown in ure.Such a concept has been used substantially in the development of antennas for base stations in wireless communications,the details of which will be found in this book. In This Book Antennas have become one of the most important technologies in modern mobile wireless communications.Many excellent books discuss concepts ortypica dtoreneral appc Most of them are textbooks for st whereas the practical issues in antenna engineering are usually included in engineering handbooks
mobile terminal antennas where critical size and cost constraints are imposed. For base stations, the requirements for high-performance antennas or arrays have pushed antenna engineers to implement more complicated RF, electrical, and/or mechanical designs to control antenna and array performance, in particular for the radiation patterns of base station antennas or arrays. Therefore, the antenna or array is designed as a subsystem rather than only an RF component. Furthermore, the antenna or array will be intelligent (smart or adaptive) if powerful signal processing functions are applied to controlling antenna performance or digitally processing signals from antennas to form a closed feedback loop. The concept of antenna design is, therefore, expanded to cover not only RF radiators, controlling circuits, or subsystems but also signal processing algorithms, as shown in Figure 2. Such a concept has been used substantially in the development of antennas for base stations in wireless communications, the details of which will be found in this book. In This Book Antennas have become one of the most important technologies in modern mobile wireless communications. Many excellent books discuss the fundamental concepts or typical designs for general applications. Most of them are textbooks for students,2–5 whereas the practical issues in antenna engineering are usually included in engineering handbooks xx Introduction TABLE 1 Features of Antennas in Personal Mobile Terminals and Base Stations Antennas in Mobile Terminals Antennas/Arrays in Base Stations Size Very small Compact Operating bands Multiple bands (up to six) for cell phones and laptops Multiple bands (up to four) for cell phones, WiFi, and Bluetooth Ultra-wideband Universal UHF bands for RFID Ultra-wideband Diversity Available in laptop and UWB wireless USB dongles Available if needed Polarization Circularly polarized in RFID handheld readers Dual polarization for cell phones, WiFi, and bluetooth Circular polarization in RFID readers and location beacons Adaptive beamforming Not available Available if needed MIMO Will be available Available if needed
Introduction xxi Control Sub-system RFcircuits Electrical circuits Mechanical structures Systen Control ssing Signal processing g2Aegataowadataonniagutyotomad and monographs.This book will focus on antenna technologies for base stations in modern mobile wireless communication systems, including the most popular applications in WPAN (UWB and RFID). WLAN(Bluetooth and WiFi).WMAN(WiMAX),WWAN (cellular phones such as GSM,CDMA,and WCDMA),and so on.The discussion il cover all aspects of antenna tec ogies,fromantennaelementdesig to antenna design in systems.Key design considerations and practical engineering issues will be highlighted in the following chapters,all written by highly experienced researchers,issues not readily found in research institutes,and universities;all of them, n to ample engineering experience,have worked for years in the research,develop- ment,and application of antennas in wireless communications. Chapter 1 Chapter I defines antenna parameters and their fundamentals.Unlike other books,we concentrate on the practical aspects of antennas and the measurement techniques for different parameters such as input ments in far-field and nea a field ranges are ation of linearly and circularly polarized antennas are also described.One important parameter,which is usually not discussed in most antenna books,is the intermodulation distortion of the antenna,which is considered here. This chapter will be well received by antenna engineers
and monographs.1,6–11 This book will focus on antenna technologies for base stations in modern mobile wireless communication systems, including the most popular applications in WPAN (UWB and RFID), WLAN (Bluetooth and WiFi), WMAN (WiMAX), WWAN (cellular phones such as GSM, CDMA, and WCDMA), and so on. The discussion will cover all aspects of antenna technologies, from antenna element design to antenna design in systems. Key design considerations and practical engineering issues will be highlighted in the following chapters, all written by highly experienced researchers, issues not readily found in other existing technical literature. The contributors are from industry, research institutes, and universities; all of them, in addition to ample engineering experience, have worked for years in the research, development, and application of antennas in wireless communications. Chapter 1 Chapter 1 defines antenna parameters and their fundamentals. Unlike other books, we concentrate on the practical aspects of antennas and the measurement techniques for different parameters such as input impedance and radiation patterns. Measurements in far-field and near- field ranges are addressed. Techniques for characterization of linearly and circularly polarized antennas are also described. One important parameter, which is usually not discussed in most antenna books, is the intermodulation distortion of the antenna, which is considered here. This chapter will be well received by antenna engineers. Introduction xxi Figure 2 Antenna technology: RF radiator, controlling subsystem, and signal processing Antenna Array Component RF circuits Electrical circuits Mechanical structures Control Sub-system Signal processing Control & Processing System Processing