This book deals with the field of identification and sensors, more precisely the possibility of collecting information remotely with RF waves (RFID). The book introduces the technology of chipless RFID starting from classical RFID and barcode, and explores the field of identification and sensors without wire, without batteries, without chip, and with tags that can even be printed on paper. A technique for automatic design of UHF RFID tags is presented , aiming at making the tags as insensitive as possible to the environment (with the ability to increase the reading range reliability), or, conversely, making them sensitive in order to produce sensors, meanwhile keeping their unique ID. The RFID advantages are discussed, along with its numerous features, and comparisons with the barcode technology are presented. After that, the new chipless RFID technology is introduced on the basis of the previous conclusions. Original technological approaches are introduced and discussed in order to demonstrate the practical and economic potential of the chipless technology.