A design of transceiver for 13.56 MHz RFID reader using the peak detector with automatic reference voltage generator and voltage limiter

In this paper, the transceiver for RFID reader using 13.56MHz as a carrier frequency and meeting International Standard ISO 14443 type A, 14443 type B and 15693 is presented. The receiver is composed of envelope detector, VGA (Variable Gain Amplifier), low pass filter, limiter, and comparator to recovery the received signal. The proposed automatic reference voltage generator can adjust the decision level of reference voltage over the received signal amplitudes. Also, the limiter can reduce the initial settling time that affects the data latency. The transmitter is designed to meet 15693 specification. By using inductor loading circuit which can swing more than power supply and make large current even under low impedance condition, it can control modulation index from 5% to 100%t and output currents from 5 mA to 240 mA in respect of each standard. The 13.56 MHz RFID reader is implemented in 0.18 μm CMOS technology at 3.3 V single supply. The chip area excluding pads is 1.5 mm × 1.5 mm.