This paper presents a brief overview to the recent developments in the field of chipless Ultra-Wide-Band (UWB) Radio Frequency Identification (RFID) systems. First, we provide introductory notes about the evolution of RFID systems and principles of their operation. Second, we give an idea how to design and encode UWB-RFID tags, and provide information about the commonly used technologies for fabrication. We also discuss possible setups to measure UWB-RFID tag's signatures, and provide an overview about the current signal processing techniques often used at the reader side to extract tags' encoding information. Finally, we show how sensors are being used in chipless UWB-RFID systems with some applications.