A Low-Power Low-Cost 24 GHz RFID Tag With a C-Flash Based Embedded Memory

The key factor in widespread adoption of Radio Frequency Identification (RFID) technology is tag cost minimization. This paper presents the first low-cost, ultra-low power, passive RFID tag, fully integrated on a single substrate in a standard CMOS process. The system combines a 24 GHz, dual on-chip antenna, RF front-end, and a C-Flash based, rewritable, non-volatile memory module to achieve full on-chip system integration. The complete system was designed and fabricated in the TowerJazz 0.18 μm CMOS technology without any additional mask adders. By embedding the RF, memory, and digital components together upon a single substrate in a standard digital process, the low-cost aspirations of the “5-cent RFID tag” become feasible. Design considerations, analysis, circuit implementations, and measurement results are presented. The entire system was fabricated on a 3.6 mm × 1.6 mm (6.9 mm²) die with the integrated antennas comprising 82% of the silicon area. The total read power was measured to be 13.2 μW, which is sufficiently supplied by the on-chip energy harvesting unit.