A 13.56 MHz transceiver SoC for multi-standard RFID reader

Abstract

A 13.56 MHz transceiver SoC supporting multi-standard RFID was proposed in this paper. Based on standard analysis, we obtained design requirements and specifications. Considering these matters, a multi-standard 13.56 MHz RFID transceiver SoC was designed. For supporting multi-standard, two structures are adopted in transmitter: ASK modulator with various modulation indexes and power control circuit which can control the recognition range between the reader and the tag. In receiver part, each component has to achieve uniformed signal process technique regardless of outside surroundings. To do this, DC voltage of the response signal is removed internally generated DC voltage is added Next, parameters of each component - for example, RC constant for envelope detector, gain of amplifier, cutoff frequency of the filter - are determined to support multi-standards. Control bits from digital part are added to change characteristics of the receiver part. Finally, the comparator with hysteresis and controllable reference voltage is designed to tune the duty cycle of receiver output pulse for proper decoding in digital baseband. Designed structure was fabricated using Chartered 0.18 $\mum$ CMOS technology. Using commercial tag and evaluation board, we can activate the tag and read the unique information of the commercial tag.