Design and implementation of an analog front-end circuit for semi-passive HF RFID tag

This paper presents an analog front-end circuit for semi-passive HF RFID tag compatible to ISO/IEC 14443 Type A. System architecture is constructed. The proposed AFE has realized much longer recognition distance than passive tags and can work normally when the magnetic field is 0.3 A/m. It was fabricated with HHNEC 0.13 μm 1P4M CMOS technology with its layout area of 416 μm×472 μm. Measurement results show that this AFE can successfully demodulate the 100% ASK modulated signal and the index of the subcarrier modulation can achieve as high as 16.4%. Its power consumption is as low as 129.6 μW. This chip met the demands of an HF semi-passive tag and made it possible to implant the temperature sensor in the tag.