A full wave voltage multiplier for passive RFID transponders is presented. The current driving capability of the proposed rectifier is remarkably improved at the cost of only a small increase in layout area compared to the widely used conventional half wave voltage multiplier. The communication distance of RFID systems can be extended due to the improved RF carrier to DC power conversion capability of the proposed voltage multiplier.

A Power on Reset signal generation circuit referencing threshold voltage without standby current consumption has been proposed. The POR signal is generated when supply voltage is larger than the sum of threshold voltages of N- and P-MOSFET.

A single chip NFC transceiver with Dual Antenna structure supporting not only NFC active and passive mode but also 13.56 MHz RFID reader and tag mode is designed and fabricated. The proposed NFC transceiver can operate as a RFID tag even without external power supply thanks to a dual antenna structure for initiator and target. The area increment due to additional target antenna is negligible because the target antenna is constructed by using a shielding layer of the initiator antenna.

We propose an ASK modulator and Antenna driver for multi-standard 13.56 MHz RFID readers and NFC devices. The proposed transmitters of RFID readers and NFC devices consist of ASK modulator, inverting output driving buffer and off-chip antenna with a matching circuit. The ASK modulation depth can easily be controlled by adjusting duty ratio by the delay line circuit. The test chip was fabricated by using a 0.35 µm double poly CMOS process. The measured results demonstrated that the proposed circuit has met the standard specifications.

A charge pump circuit suitable for positive high voltage generators at sub-1.5 V range is presented. The proposed heap-pump circuit provides a high voltage generator having not only high pumping efficiency by eliminating threshold voltage drop but also simplest single phase clock scheme.