The use of electromagnetic fields to detect and track tags attached to various objects is known as radio frequency identification. It has three components-radio transponder, a radio transmitter and a receiver. Whenever a tag is triggered by an electromagnetic pulse, it transmits digital data back to the receiver. This is the underlying principle on which this domain operates. These devices can be attached to animals, humans, clothes, cash and possessions. These can be applied in diverse areas such as tracking of animals and persons, access management, airport baggage tracking logistics, machine readable travel documents, tracking and billing processes, tracking of goods, contactless payment and toll collection, smartdust, timing sports events, etc. The book aims to shed light on some of the unexplored topics of this field. Most of the topics introduced in this book cover new techniques and applications of radio frequency identification. Those in search of information to further their knowledge will be greatly assisted by this book.