CHAPTER 16
MULTI-ANTENNA BACKSCATTERED CHIPLESS RFID DESIGN
16.1 INTRODUCTION
The adoption of RFID technology has been flagged in various commercial industry sectors including farming, retail, manufacturing, and others; however, there has not been universal adoption. This is due to many factors, including the tag cost, system reliability, and privacy concerns, but many of these issues could be addressed once the technology is matured to the point where it is ready for large-scale implementations. Since RFID has such a broad definition, systems can be applied in a variety of different forms, depending upon the specific requirements of the client [1]. System parameters such as reading range, read accuracy, tag size, and tag cost will determine which form of RFID is most suitable for a particular application. For low-cost solutions the most appropriate system is chipless RFID.
Chipless tags have their identification code written once only. This means that their functionality is limited; however, generally since there is no requirement for surface-mounted components on-board, we can mass-produce the transponders at a cost low enough to be competitive with barcodes. They generally operate by encoding an identification number into the time domain or frequency domain, creating digital bits that we refer to as time-signature and frequency-signature ...
