This white paper describes a reference design with circuits and an antenna for a UHF RFID system. A new Class 2 (Gen 2) tag was designed, including the extremely low-power integrated circuit integrated with an inexpensive printed antenna. Details on the design of the rectifier, power regulator, demodulator, reset circuit, modulator, and antenna are highlighted. The paper includes a system-level software verification of the RFID tag system to determine proper voltage regulation and signal demodulation.