WirelesslyPowered Printed Temperature Sensor with an UltraLowPower and HighSensitivity CMOS Readout IC This paper presents a wirelesslypowered highsensitivity printed temperature sensor (TS). The proposed system consists of a xe2x88x9217dBm sensitivity RFDC conversion circuit, a 2.2 xc2xb5W readout interface, and a printed NiO thermistor sensor. The 1 mm2 printed NiO film has a good sensitivity index (B value) of 4000 K, but has high resistance (Mxcexa9). The conventional readout system has difficulty detecting small resistance changes in the large thermal resistance range while only consuming a few microwatts, which is a need for enabling RF power sensors remotely. A lownoise readout IC was designed to convert the resistance changes to digital codes. The proposed TS achieves a resolution of 0.04xc2xb0Ccode in a temperature range of xe2x88x9220xc2xb0C to 90xc2xb0C, and measurement deviation within xc2xb11.1%, while consuming only 2.2 nJ per conversion.

A UHF SemiPassive RFID System with PhotovoltaicThermoelectric Energy Harvesting for Wireless Sensor Networks A semipassive ultrahigh frequency (UHF) radio frequency identification (RFID) system is presented. The reconfigurable architecture of tag is proposed to be compatible with passive and active operating modes. The read range of RFID system and the lifetime of tag is increases by frequency locked onchip oscillator topology. The transceiver is implemented in 0.18xc2xb5m standard CMOS process. The sensitivity of tag is xe2x88x9218dBm for passive mode and xe2x88x9240dBm for active mode with 1.2xc2xb5W power consumption under the supply voltage of 0.8V. The output power is xe2x88x9210dBm for active transmitting mode and the power consumption is 450xc2xb5W under the supply voltage of 1V.