Book excerpt: In the era of information communication technology (ICT), radio frequency identification (RFID) has been going through tremendous development. RFID technology has the potential of replacing barcodes due to its large information carrying capacity, flexibility in operations, and applications. The deployment of RFID has been hindered by its cost. However, with the advent of low powered ICs, energy scavenging techniques, and low-cost chipless tags, RFID technology has achieved significant development. This book addresses the new reader architecture, presents fundamentals of chipless RFID systems, and covers protocols. It also presents proof-of-concept implementations with potential to replace trillions of barcodes per year. Overall, this resource aims to not only explain the technology, but to make the chipless RFID reader system a viable commercial product for mass deployment. It is certainly a very useful resource in the new field.