Low-cost CW-LFM radar sensor at 100 GHz

This paper presents a W-band high-resolution radar sensor for short-range applications. Low-cost technologies have been properly selected in order to implement a versatile and easily scalable radar system. A large operational bandwidth of 9 GHz, required for obtaining high-range resolution, is attained by means of a frequency multiplication-based architecture. The system characterization to identify the performance-limiting stages and the subsequent design optimization are presented. The assessment of system performance for several representative applications has been carried out

A study of RF-over-fibre based active RFID indoor location system

Location systems developed for indoor environments have attracted increasing interest, as a result of the rapidly growing location and navigation services provided by the Global Positioning System (GPS). Location information of people and objects can be used to cooperate with existing communication or database systems to provide abundant services to system operators and end users. For example, equipment tracking in hospitals ensure that location of the appropriate equipment can be provided simultaneously with necessary medical services; attendee tracking at conferences may encourage more efficient communications and networking; location of valuable assets in factories or warehouses aids logistics and protects these assets from theft. Since established global and terrestrial navigation systems cannot provide reliable location services in indoor environments, these demands are increasingly being met by wireless indoor location systems. A review of the existing systems reveals that the current systems are able to provide either an accurate location service with sophisticated system design at higher cost or a less accurate location service by means of integrated systems supplemented by existing facilities. This thesis presents a novel design of an indoor location system that is based on an RF-over-fibre backbone network, which is able to provide high location accuracy while the network infrastructure can be shared with multiple wireless systems. It is the first such demonstrator in this area. This research has been conducted by the author through a research project called The Intelligent Airport (TINA), which is the motivation for this research. The TINA project seeks to develop a new seamless wireless/wired ubiquitous infrastructure with high levels of computational capability to meet the application requirements of future airport environments. In the TINA system, multiple wireless services are provided through an integrated system supported by an RF-over-Fibre network, which transports RF signals through optical fibres. The active RFID indoor location unit is an essential part of the TINA system, which will facilitate the infrastructure to provide location-based services. The thesis describes the detailed design of the active RFID indoor location system proposed for the TINA project, and a few key issues discovered during trials of the demonstration system developed. The overall system design, including ranging technique, TDOA location finding algorithm, and hardware implementation, is presented in this thesis. Particular contributions also include a numerical algorithm for solving target location from TDOA measurement and a technique to determine the chirp linearity requirement. The field trial results of the system design demonstrate the principals and their location performance. The system has the potential to be extended to other scenarios where RF-over-fibre networks are employed and accurate location ability is desired