Long range, low power UHF RFID analog front-end suitable for batteryless wireless sensors

A long range, low power UHF RFID analog front-end suitable for batteryless wireless sensors has been designed using a low cost 0.35 μm CMOS standard process. The proposed front-end architecture allows the implementation of power management techniques that together with the power optimized blocks such as voltage limiter, ASK demodulator... provides a long reading range. The implemented voltage multiplier uses Schottky diodes to provide efficiencies higher than 35%. The measured UHF RFID analog front-end current consumption is 7.4 μA. When assembling the analog front-end to a matched dipole antenna, the analog front-end would be able to provide a wireless communication up to 2.4m, from a 2W EIRP output power reader to a digital module + sensor, with an average power consumption up to 37.5 μW. These characteristics allow the use of the proposed analog front-end in batteryless wireless sensor networks.