This paper provides a summary of the basic concepts of retrodirective antenna arrays. Originally this class of antenna was developed in the 1960s for direct satellite-to-ground transmission of high-power microwave energy. The explosive growth of mobile communications has, in the authors' opinion, reopened the debate for alternative applications of retrodirective array techniques. Advances in microstrip antenna design coupled with the availability of integrated circuit amplifier and mixer components permit minimum-complexity retrodirective antenna arrays to be constructed. Several different planar retrodirective antenna architectures are presented and their basic operational characteristics given. A novel application for co-operating retrodirective antennas in a duplex communication link with inherent space division multiple access capability is also described. Finally some of the operational parameters which could ultimately limit the performance of this class of antenna are discussed.
{"title":"Self-phasing antenna array techniques for mobile communications applications","authors":"V. Fusco, S. Karode","doi":"10.1049/ECEJ:19990608","DOIUrl":"https://doi.org/10.1049/ECEJ:19990608","url":null,"abstract":"This paper provides a summary of the basic concepts of retrodirective antenna arrays. Originally this class of antenna was developed in the 1960s for direct satellite-to-ground transmission of high-power microwave energy. The explosive growth of mobile communications has, in the authors' opinion, reopened the debate for alternative applications of retrodirective array techniques. Advances in microstrip antenna design coupled with the availability of integrated circuit amplifier and mixer components permit minimum-complexity retrodirective antenna arrays to be constructed. Several different planar retrodirective antenna architectures are presented and their basic operational characteristics given. A novel application for co-operating retrodirective antennas in a duplex communication link with inherent space division multiple access capability is also described. Finally some of the operational parameters which could ultimately limit the performance of this class of antenna are discussed.","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"1222 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132306975","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}
This paper provides a review, directed at scientists and engineers concerned with microsystems technology, of advances in microelectromechanical systems (MEMS). The emphasis is on silicon technology, where the electrical properties of the material are exploited in circuitry and the mechanical properties are used in sensor and microstructure applications. Developments in surface micromachining are discussed, and applications in sensors, microelectronic devices, vacuum microanalysis systems, microfluidics, and optoelectronic subsystems are reviewed. Some emerging technologies are assessed and promising new research directions are identified.
{"title":"Recent developments in micromachined silicon","authors":"D. Moore, R. Syms","doi":"10.1049/ECEJ:19990603","DOIUrl":"https://doi.org/10.1049/ECEJ:19990603","url":null,"abstract":"This paper provides a review, directed at scientists and engineers concerned with microsystems technology, of advances in microelectromechanical systems (MEMS). The emphasis is on silicon technology, where the electrical properties of the material are exploited in circuitry and the mechanical properties are used in sensor and microstructure applications. Developments in surface micromachining are discussed, and applications in sensors, microelectronic devices, vacuum microanalysis systems, microfluidics, and optoelectronic subsystems are reviewed. Some emerging technologies are assessed and promising new research directions are identified.","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132668627","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":"Letters to the Editor: EMC of PCBs","authors":"H. O. Ibekwe","doi":"10.1049/ecej:19990604","DOIUrl":"https://doi.org/10.1049/ecej:19990604","url":null,"abstract":"","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"397 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116023773","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}
For pt.1 see ibid., vol.8, no. 4, p.185-94 (1999). Printed circuit boards (PCBs) are widely used in electronic equipment and systems. Application of good EMC (electromagnetic compatibility) practices to their design usually helps to achieve compliance with EMC regulations at much lower cost than alternative EMC measures at higher levels of integration, and also improves signal integrity. This paper discusses in detail techniques for improving the power supply of a PCB and using transmission lines.
{"title":"PCB design techniques for lowest-cost EMC compliance. Part 2","authors":"M. K. Armstrong","doi":"10.1049/ECEJ:19990503","DOIUrl":"https://doi.org/10.1049/ECEJ:19990503","url":null,"abstract":"For pt.1 see ibid., vol.8, no. 4, p.185-94 (1999). Printed circuit boards (PCBs) are widely used in electronic equipment and systems. Application of good EMC (electromagnetic compatibility) practices to their design usually helps to achieve compliance with EMC regulations at much lower cost than alternative EMC measures at higher levels of integration, and also improves signal integrity. This paper discusses in detail techniques for improving the power supply of a PCB and using transmission lines.","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124042341","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 use of satellite systems in the implementation of third-generation mobile communication systems obviously involves a propagation environment for the signal different from that in the conventional terrestrial first- and second-generation systems. The propagation conditions and phenomena met with are embraced by the expression 'land mobile satellite (LMS) channel'. This paper reviews the studies of the LMS channel reported in the literature. The various models are classified and compared in such a way that their similarities and differences are apparent.
{"title":"Modelling the land mobile satellite channel: a review","authors":"M. Karaliopoulos, F. Pavlidou","doi":"10.1049/ECEJ:19990506","DOIUrl":"https://doi.org/10.1049/ECEJ:19990506","url":null,"abstract":"The use of satellite systems in the implementation of third-generation mobile communication systems obviously involves a propagation environment for the signal different from that in the conventional terrestrial first- and second-generation systems. The propagation conditions and phenomena met with are embraced by the expression 'land mobile satellite (LMS) channel'. This paper reviews the studies of the LMS channel reported in the literature. The various models are classified and compared in such a way that their similarities and differences are apparent.","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130803982","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}
For many decades television engineers have dreamt of 'the TV on the wall'. The display engineer has always answered, 'maybe in about ten years time'. However now, for the first time, there is more than one technology offering a real possibility that the large, thin, flat television display will become a reality. There are three flat-panel technologies to consider: active matrix liquid crystal, plasma-addressed liquid crystal and plasma display panels. Television receivers utilising each of these approaches are appearing on the consumer market or are promised in the near future, albeit at a high price and in small quantities. The viability of high-definition TV (HDTV) is considered by some to be crucially dependent on the development of such displays and their promise for this application is considered. This paper reviews the key features of the three approaches and compares and contrasts their particular advantages and disadvantages for television applications. Finally, an attempt is made to answer the question posed by the title of the paper.
{"title":"The TV on the wall: has its time come?","authors":"D. W. Parker, A. Knapp, T. Baller","doi":"10.1049/ECEJ:19990501","DOIUrl":"https://doi.org/10.1049/ECEJ:19990501","url":null,"abstract":"For many decades television engineers have dreamt of 'the TV on the wall'. The display engineer has always answered, 'maybe in about ten years time'. However now, for the first time, there is more than one technology offering a real possibility that the large, thin, flat television display will become a reality. There are three flat-panel technologies to consider: active matrix liquid crystal, plasma-addressed liquid crystal and plasma display panels. Television receivers utilising each of these approaches are appearing on the consumer market or are promised in the near future, albeit at a high price and in small quantities. The viability of high-definition TV (HDTV) is considered by some to be crucially dependent on the development of such displays and their promise for this application is considered. This paper reviews the key features of the three approaches and compares and contrasts their particular advantages and disadvantages for television applications. Finally, an attempt is made to answer the question posed by the title of the paper.","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125737930","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}
Synthetic aperture radar (SAR) data provide unique information about the Earth's surface and biodiversity, including critical data for natural hazards and resource assessments. The ability to calculate the cross-section of a scatterer for any transmit and receive polarisation combination provides detailed information about vegetation for assessing changes in land cover, biomass and forest regrowth. Unique SAR interferometric measurements, predominantly large-scale surface change at fine resolution, are used to generate topographic data sets, monitor surface topographic change, and measure glacier ice velocity. The LightSAR mission, planned for launch in 2002 will be optimised for polarimetric and interferometric data acquisition in order to provide long-term observations of the Earth's changing conditions.
{"title":"Applications of Imaging Radar Data in Earth Science Investigations","authors":"D. Evans","doi":"10.1049/ECEJ:19990504","DOIUrl":"https://doi.org/10.1049/ECEJ:19990504","url":null,"abstract":"Synthetic aperture radar (SAR) data provide unique information about the Earth's surface and biodiversity, including critical data for natural hazards and resource assessments. The ability to calculate the cross-section of a scatterer for any transmit and receive polarisation combination provides detailed information about vegetation for assessing changes in land cover, biomass and forest regrowth. Unique SAR interferometric measurements, predominantly large-scale surface change at fine resolution, are used to generate topographic data sets, monitor surface topographic change, and measure glacier ice velocity. The LightSAR mission, planned for launch in 2002 will be optimised for polarimetric and interferometric data acquisition in order to provide long-term observations of the Earth's changing conditions.","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"188 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127589217","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 explosive growth in the use of the Internet has made it an attractive medium for the distribution of multimedia material. However, it has become apparent that the digital nature of such material makes enforcement and proof of copyright ownership virtually impossible. Another problem with digital images and video is that undetectable modifications can be made with very simple and widely available equipment. As a result, the use of digital material for evidential purposes has been called into question at a time when the video surveillance industry is moving towards digital rather than analogue systems. Digital watermarking promises to address these issues. Different types of watermarking systems exist for different applications robust watermarks for copyright protection and fragile watermarks for integrity checking applications. The question is just how good are current digital watermark techniques and what are the issues surrounding their use in real-life situations?
{"title":"Digital watermarking: applications, techniques and challenges","authors":"R. Barnett","doi":"10.1049/ECEJ:19990401","DOIUrl":"https://doi.org/10.1049/ECEJ:19990401","url":null,"abstract":"The explosive growth in the use of the Internet has made it an attractive medium for the distribution of multimedia material. However, it has become apparent that the digital nature of such material makes enforcement and proof of copyright ownership virtually impossible. Another problem with digital images and video is that undetectable modifications can be made with very simple and widely available equipment. As a result, the use of digital material for evidential purposes has been called into question at a time when the video surveillance industry is moving towards digital rather than analogue systems. Digital watermarking promises to address these issues. Different types of watermarking systems exist for different applications robust watermarks for copyright protection and fragile watermarks for integrity checking applications. The question is just how good are current digital watermark techniques and what are the issues surrounding their use in real-life situations?","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114636393","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}
Application of good EMC (electromagnetic compatibility) practices to the design of printed circuit boards (PCBs) usually helps to achieve the EMC performance required of equipment and systems at much lower cost than alternative EMC measures at higher levels of integration, such as whole-product shielding. EMC design is a complex topic, but the proven best EMC practices for generalised PCB layout can be fairly simply stated and grouped into five techniques, which interact with each other to give dramatic improvements in EMC performance. This paper discusses the techniques of circuit segregation, interface suppression and the use of ground and power planes.
{"title":"PCB design techniques for lowest-cost EMC compliance. Part 1","authors":"M. K. Armstrong","doi":"10.1049/ECEJ:19990402","DOIUrl":"https://doi.org/10.1049/ECEJ:19990402","url":null,"abstract":"Application of good EMC (electromagnetic compatibility) practices to the design of printed circuit boards (PCBs) usually helps to achieve the EMC performance required of equipment and systems at much lower cost than alternative EMC measures at higher levels of integration, such as whole-product shielding. EMC design is a complex topic, but the proven best EMC practices for generalised PCB layout can be fairly simply stated and grouped into five techniques, which interact with each other to give dramatic improvements in EMC performance. This paper discusses the techniques of circuit segregation, interface suppression and the use of ground and power planes.","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125015048","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}
Token ring networks are the second most commonly used type of local-area network (LAN). The second version of the formal token ring multiple access mechanism, ISO 8802/5, was released in late 1995 and this rationalised many of the new developments, e.g. the 16 Mbit/s solutions. The latest innovations are the full duplex dedicated token ring and the development of a 100 Mbit/s high-speed token ring solution. To many people's surprise there is an extensive legacy of token ring installations and the latest innovations, such as token ring switching, are an attempt to maintain and support this significant market presence. Token ring is designed to provide high throughput under heavy loads (something which is normally impossible for Ethernet to sustain) but in most cases it is used in typical office environments where there is infrequent occurrence of heavy loads.
{"title":"ISO 8802/5 token ring local-area networks","authors":"C. Smythe","doi":"10.1049/ECEJ:19990406","DOIUrl":"https://doi.org/10.1049/ECEJ:19990406","url":null,"abstract":"Token ring networks are the second most commonly used type of local-area network (LAN). The second version of the formal token ring multiple access mechanism, ISO 8802/5, was released in late 1995 and this rationalised many of the new developments, e.g. the 16 Mbit/s solutions. The latest innovations are the full duplex dedicated token ring and the development of a 100 Mbit/s high-speed token ring solution. To many people's surprise there is an extensive legacy of token ring installations and the latest innovations, such as token ring switching, are an attempt to maintain and support this significant market presence. Token ring is designed to provide high throughput under heavy loads (something which is normally impossible for Ethernet to sustain) but in most cases it is used in typical office environments where there is infrequent occurrence of heavy loads.","PeriodicalId":127784,"journal":{"name":"Electronics & Communication Engineering Journal","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1999-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132392380","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}
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