Abstract: A new,low-cost RFID tag analog front-end compatible with ISO 14443A and ISO 14443B is presented.By substituting conventional multi-circle antenna with single-circle antenna,the package cost of the tag is greatly reduced.Based on this exasperate antenna performance,a new rectifier with high power conversion efficiency and low turn-on voltage is presented.The circuit is implemented in an SMIC 0.18μm EEPROM process.Measurement results show that with a 120kΩ load,the power conversion efficiency reaches as high as 36%.For a sinusoidal wave with magnitude of 0.5V,the output DC voltage reaches 1V,which is high enough for RFID tags.The read distance is as far as 22cm.

Key words: RFID, analog front-end, charge pump, low power, low voltage, single-circle antenna