Power efficiency of the RF transmitter stage in mobile handsets has a direct impact on battery capacity as well as talk-time between battery recharge cycles. Unfortunately the power amplifier (PA) linearisation methods in common usage today to meet the linearity specification of standards such as GSM EDGE, TETRA and UMTS result in low DC to RF efficiency. This paper discusses the relationship between linearity and transmitter efficiency and reviews various linearisation schemes: Cartesian loop, polar loop, 2nd harmonic injection, envelope elimination and restoration (EER), predistortion methods, and synthesis techniques (e.g. LINC and CALLUM). The paper also shows that to increase the power efficiency (and thus talk-time) hybrid solutions to power amplifier linearisation are required and these are also discussed.
{"title":"Increasing the talk-time of mobile radios with efficient linear transmitter architectures","authors":"S. Mann, M. Beach, P. Warr, J. Mcgeehan","doi":"10.1049/ECEJ:20010204","DOIUrl":"https://doi.org/10.1049/ECEJ:20010204","url":null,"abstract":"Power efficiency of the RF transmitter stage in mobile handsets has a direct impact on battery capacity as well as talk-time between battery recharge cycles. Unfortunately the power amplifier (PA) linearisation methods in common usage today to meet the linearity specification of standards such as GSM EDGE, TETRA and UMTS result in low DC to RF efficiency. This paper discusses the relationship between linearity and transmitter efficiency and reviews various linearisation schemes: Cartesian loop, polar loop, 2nd harmonic injection, envelope elimination and restoration (EER), predistortion methods, and synthesis techniques (e.g. LINC and CALLUM). The paper also shows that to increase the power efficiency (and thus talk-time) hybrid solutions to power amplifier linearisation are required and these are also discussed.","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125669020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bodyworn antennas are found in a wide range of medical, military and personal communication applications, yet reliable communication from the surface of the human body still presents a range of engineering challenges. At UHF and microwave frequencies, bodyworn antennas can suffer from reduced efficiency due to electromagnetic absorption in tissue, radiation pattern fragmentation and variations in feed-point impedance. The significance and nature of these effects are system specific and depend on the operating frequency, propagation environment and physical constraints on the antenna itself. This paper describes how numerical electromagnetic modelling techniques such as FDTD (finite-difference time-domain) can be used in the design of bodyworn antennas. Examples are presented for 418 MHz, 916/spl middot/5 MHz and 2/spl middot/45 GHz, in the context of both biomedical signalling and wireless personal-area networking applications such as the Bluetooth/sup TM/ wireless technology.
{"title":"Numerical analysis of bodyworn UHF antenna systems","authors":"W. Scanlon, N. Evans","doi":"10.1049/ECEJ:20010203","DOIUrl":"https://doi.org/10.1049/ECEJ:20010203","url":null,"abstract":"Bodyworn antennas are found in a wide range of medical, military and personal communication applications, yet reliable communication from the surface of the human body still presents a range of engineering challenges. At UHF and microwave frequencies, bodyworn antennas can suffer from reduced efficiency due to electromagnetic absorption in tissue, radiation pattern fragmentation and variations in feed-point impedance. The significance and nature of these effects are system specific and depend on the operating frequency, propagation environment and physical constraints on the antenna itself. This paper describes how numerical electromagnetic modelling techniques such as FDTD (finite-difference time-domain) can be used in the design of bodyworn antennas. Examples are presented for 418 MHz, 916/spl middot/5 MHz and 2/spl middot/45 GHz, in the context of both biomedical signalling and wireless personal-area networking applications such as the Bluetooth/sup TM/ wireless technology.","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"106 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122442256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the semiconductor industry's evolutionary life cycle, the speed at which products are introduced to the market-place is key to the competitive success of individual companies. The semiconductor industry is classed as a fast-changing industry in which product technology, manufacturing process technology and industry organisation need to be continuously updated in relatively short cycle times. This paper looks at the test engineering aspect of the IC (integrated circuit) product development process and describes how an emerging 'virtual test' methodology can be effectively applied to reduce the overall product development time for semiconductor devices.
{"title":"Virtual test reduces semiconductor product development time","authors":"T. Hogan, D. Heffernan","doi":"10.1049/ECEJ:20010205","DOIUrl":"https://doi.org/10.1049/ECEJ:20010205","url":null,"abstract":"In the semiconductor industry's evolutionary life cycle, the speed at which products are introduced to the market-place is key to the competitive success of individual companies. The semiconductor industry is classed as a fast-changing industry in which product technology, manufacturing process technology and industry organisation need to be continuously updated in relatively short cycle times. This paper looks at the test engineering aspect of the IC (integrated circuit) product development process and describes how an emerging 'virtual test' methodology can be effectively applied to reduce the overall product development time for semiconductor devices.","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117249717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Network computing is generally considered to be an unsuccessful initiative. It is strongly associated in the minds of many with the overhyped network computer that failed to capture a significant market share from PCs. However, network computing and network computers are not synonymous. In fact, one of the major benefits of network computing is the ability to tailor applications to the capabilities of heterogeneous client devices. Given the very fast growing mobile computing market, with its numerous and diverse terminal types, network computing could at last realise its full potential. This tutorial paper provides an overview of computing from the early mainframes to today's multiplicity of computing devices. The advantages of network computing are discussed and an overview is provided of some of the underpinning technologies. To provide an insight into the potential of network computing, two applications are described. Some overall conclusions are also given.
{"title":"Network computing: a tutorial review","authors":"M. Revett, I. Boyd, C. Stephens","doi":"10.1049/ECEJ:20010101","DOIUrl":"https://doi.org/10.1049/ECEJ:20010101","url":null,"abstract":"Network computing is generally considered to be an unsuccessful initiative. It is strongly associated in the minds of many with the overhyped network computer that failed to capture a significant market share from PCs. However, network computing and network computers are not synonymous. In fact, one of the major benefits of network computing is the ability to tailor applications to the capabilities of heterogeneous client devices. Given the very fast growing mobile computing market, with its numerous and diverse terminal types, network computing could at last realise its full potential. This tutorial paper provides an overview of computing from the early mainframes to today's multiplicity of computing devices. The advantages of network computing are discussed and an overview is provided of some of the underpinning technologies. To provide an insight into the potential of network computing, two applications are described. Some overall conclusions are also given.","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"87 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127995235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper examines the changes that are taking place in telecommunication transport networks, from a hierarchical digital architecture to the possibility of an all-optical network for meeting the ever-changing needs of a global multiservice communication system. It focuses on how this is driving optical component technology and its impact on the next generation of optical transmission equipment.
{"title":"The evolution of the telecommunications transport architecture: from megabit/s to terabit/s","authors":"J. Ash, S. Ferguson","doi":"10.1049/ECEJ:20010103","DOIUrl":"https://doi.org/10.1049/ECEJ:20010103","url":null,"abstract":"The paper examines the changes that are taking place in telecommunication transport networks, from a hierarchical digital architecture to the possibility of an all-optical network for meeting the ever-changing needs of a global multiservice communication system. It focuses on how this is driving optical component technology and its impact on the next generation of optical transmission equipment.","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126602498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Advanced electromagnetic analysis of passive and active planar structures [Book Review]","authors":"J. James","doi":"10.1109/mcd.2001.968920","DOIUrl":"https://doi.org/10.1109/mcd.2001.968920","url":null,"abstract":"","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115661721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As the encroachment of portable electronics into everyday life continues, the demand for improved power sources is continuing to increase. New technologies such as nickel metal hydride and lithium ion batteries have largely replaced nickel cadmium systems because of their superior performance. The paper reviews the developments in battery technology and looks ahead to the future of portable power sources. In doing so it aims to advise the reader on the possible future technologies that they may one day be using.
{"title":"Future power sources for mobile communications","authors":"K. Green, J. C. Wilson","doi":"10.1049/ECEJ:20010104","DOIUrl":"https://doi.org/10.1049/ECEJ:20010104","url":null,"abstract":"As the encroachment of portable electronics into everyday life continues, the demand for improved power sources is continuing to increase. New technologies such as nickel metal hydride and lithium ion batteries have largely replaced nickel cadmium systems because of their superior performance. The paper reviews the developments in battery technology and looks ahead to the future of portable power sources. In doing so it aims to advise the reader on the possible future technologies that they may one day be using.","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126171591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Kenington, K. Hayler, P. Moss, D. Edwards, A. Jenkins, M. Johnstone
The UK digital terrestrial television (DTT) network has completed its first phase of roll-out, with over 70% of the population now able to receive all six digital multiplexes. Whilst this is an impressive achievement, the current analogue TV network can cover 99.7% of the UK population and digital satellite systems can boast virtually 100% coverage, so DTT still has some way to go. DTT coverage must improve in order to make analogue switch-off a politically acceptable reality and to compete directly with satellite in value-added services, such as shopping or banking. Analogue switch-off is a particularly desirable goal, as it would release a significant amount of valuable spectrum for use by other commercial services (e.g. mobile telephony). This paper addresses the use of transposers, in a manner similar to that of the current analogue TV network, in order to extend coverage cost-effectively to those viewers currently unable to receive all of the digital multiplexes. A number of transposer designs are considered, employing both DSP and high-temperature superconducting (HTS) techniques, and results presented on some of the technologies employed.
{"title":"Transposer systems for digital terrestrial television","authors":"P. Kenington, K. Hayler, P. Moss, D. Edwards, A. Jenkins, M. Johnstone","doi":"10.1049/ECEJ:20010102","DOIUrl":"https://doi.org/10.1049/ECEJ:20010102","url":null,"abstract":"The UK digital terrestrial television (DTT) network has completed its first phase of roll-out, with over 70% of the population now able to receive all six digital multiplexes. Whilst this is an impressive achievement, the current analogue TV network can cover 99.7% of the UK population and digital satellite systems can boast virtually 100% coverage, so DTT still has some way to go. DTT coverage must improve in order to make analogue switch-off a politically acceptable reality and to compete directly with satellite in value-added services, such as shopping or banking. Analogue switch-off is a particularly desirable goal, as it would release a significant amount of valuable spectrum for use by other commercial services (e.g. mobile telephony). This paper addresses the use of transposers, in a manner similar to that of the current analogue TV network, in order to extend coverage cost-effectively to those viewers currently unable to receive all of the digital multiplexes. A number of transposer designs are considered, employing both DSP and high-temperature superconducting (HTS) techniques, and results presented on some of the technologies employed.","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127141596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The widespread use of photonic systems having microwave modulation bandwidths, coupled with the inclusion of photonic components in microwave and millimetre-wave systems, is creating a demand for efficient characterisation techniques. In particular, new tools will be required for the measurement of fundamental quantities such as the microwave frequency response, bandwidth, gain and return loss of microwave photonic components. However, existing lightwave measurement techniques are primitive when compared with conventional RF and microwave network analysis. This paper provides a review of the theory and techniques used for the small-signal characterisation of microwave photonic components. State-of-the-art architectures for lightwave network analysers and the corresponding two-port calibration techniques are described.
{"title":"Recent developments in lightwave network analysis","authors":"S. Iezekiel, B. Elamaran, R. Pollard","doi":"10.1049/ECEJ:20010206","DOIUrl":"https://doi.org/10.1049/ECEJ:20010206","url":null,"abstract":"The widespread use of photonic systems having microwave modulation bandwidths, coupled with the inclusion of photonic components in microwave and millimetre-wave systems, is creating a demand for efficient characterisation techniques. In particular, new tools will be required for the measurement of fundamental quantities such as the microwave frequency response, bandwidth, gain and return loss of microwave photonic components. However, existing lightwave measurement techniques are primitive when compared with conventional RF and microwave network analysis. This paper provides a review of the theory and techniques used for the small-signal characterisation of microwave photonic components. State-of-the-art architectures for lightwave network analysers and the corresponding two-port calibration techniques are described.","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129861439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Virtual Centre of Excellence in Mobile and Personal Communications-Mobile VCE-is a not-for-profit company established as a joint initiative of the mobile communications industry and leading research universities, with support from the UK government. It is an acknowledged success of the government's Foresight exercise. Its innovative approach provides companies with a highly cost-leveraged means of accessing the best of the academic base to undertake international-level, industry-led research to underpin the future development of wireless communications as it converges with the Internet and broadcast industries.
{"title":"Mobile VCE: the convergence of industry and academia","authors":"W. Tuttlebee","doi":"10.1049/ECEJ:20000602","DOIUrl":"https://doi.org/10.1049/ECEJ:20000602","url":null,"abstract":"The Virtual Centre of Excellence in Mobile and Personal Communications-Mobile VCE-is a not-for-profit company established as a joint initiative of the mobile communications industry and leading research universities, with support from the UK government. It is an acknowledged success of the government's Foresight exercise. Its innovative approach provides companies with a highly cost-leveraged means of accessing the best of the academic base to undertake international-level, industry-led research to underpin the future development of wireless communications as it converges with the Internet and broadcast industries.","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115053335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：