AbstractsComputer Science

Radio frequency identification (RFID) has become one of the fastest growing wireless technologies. An RFID system is a real-time processor that enables the information stored on a tag to be tracked and exchanged remotely with an RFID reader. The RFID tag plays a critical role in determining the overall performance of the entire system, as well as its size, cost and detection range. In this thesis, various miniaturized RFID tag antennas are investigated and implemented for conventional and emerging passive ultra high frequency (UHF) RFID applications. First, the design and experimental evaluation of three compact printed tag antennas including folded, 2D and 3D meander monopoles are presented. Next, designing a new miniaturized tunable passive UHF RFID tag is undertaken with the operation frequency covering the entire range of the UHF RFID regulated bands (840-960 MHz). This design method not only can be used in tags targeting the global RFID market, but also is crucial for the successful implementation of an RFID system that is tolerant of detuning due to fabrication process variations and loading of deployment environment. As well, a low profile RFID tag consisting of a compact microstrip patch antenna backed by a mushroom-type Electromagnetic Band Gap (EBG) structure is proposed. This design which achieves an area reduction of 29.11% compared to a conventional patch yields a maximum reading range of around 11 m as a free standing tag and when attached to a metallic surface.To extend the reading range of the RFID tag, a solar panel is integrated with the patch antenna to boost the RFID chip's operating power. Furthermore, new aspects of antenna and RFID chip integration in multi-port/antenna arrangements are explored through the design and measurement of tag prototypes.RFID technology has recently been employed in sensor applications for low-cost low-power wireless sensor node implementation. This thesis also presents novel dual-port UHF RFID tag antennas for simultaneous wireless identification and sensor applications. Special RFID tag antennas are designed and integrated with passive resistive sensors demonstrating detection of sensor data by utilizing a commercial RFID reader. Finally, another RFID-tag-sensor for transmission of generic sensor data is implemented, which also includes solar energy harvesting. This design is further improved by employing a novel two-port patch antenna that collects the ambient RF energy through its second port. A reliable RFID communication range of up to 27 m was achieved in an indoor measurement scenario, which represents, to the author's knowledge, the longest distance ever reported for similar sensor-enhanced RFID tags. L'identification par radiofréquence (RFID) est devenue l'une des technologies sans-fil qui évoluent le plus rapidement. Un système RFID est un processeur en temps réel qui permet que l'information stockée sur une étiquette soit suivi et remplacée à distance à l'aide d'un lecteur RFID. L'étiquette RFID est un facteur déterminant pour la performance d'un…