High-Sensitivity CMOS RF-DC Converter in HF RFID Band

In this letter, a fully-integrated RF-DC converter operating at the HF RFID working frequency (13.56 MHz) and realized in 350 nm CMOS technology is presented. It is based on a Dickson's rectifier, a Pelliconi's charge pump driven by a 50 kHz ring oscillator, and a voltage monitor. Mathematical model is developed and verified through simulations and measurements. Results show a sensitivity of -19 dBm with related output voltage of 0.5 V. Moreover, taking advantage from the internal voltage monitor, the suitability of the proposed architecture to pilot RFID-based sensor boards has been proved.