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.

A SolarThermoelectricTriboelectricVibrationRF Hybrid Energy Harvesting based High Efficiency Wireless Power Receiver This paper presents a RFSolarThermoelectricTriboelectricVibration hybrid energy harvesting based high efficiency wireless power receiver (WPR). The proposed WPR architecture incorporates a highpower path and a lowpower path maintaining high power conversion efficiency (PCE) over a wide input power range (xe2x88x9210 dBm to 30 dBm). Timedomain Maximum Power Point Tracking (MPPT) is proposed for SolarThermal Energy Harvester. High Efficiency Full Wave Rectifier (FWR) is designed for TriboelectricVibration Rectifier. A 5.8 GHz RF DCConverter with adaptive matching is proposed to increase the dynamic range of input power. The chip is implemented in  0.18 mu mathrmm  BipolarCMOSDMOS (BCD) process. The die area of the chip is 2.8 mm x 5.0 mm, including the pads. The highpower RFDC converter operating at 5.8 GHz frequency achieves a measured PCE of 76.9% at 30 dBm (1 W). The solar energy harvester achieves a peak PCE of 69.85%. The lowpower RFDC converters operating at 900 MHz and 2.4 GHz achieve peak measured efficiencies of 73% and 71.9% at 0 dBm (1 mW), respectively. The BuckBoost DCDC converter employed in the proposed WPR architecture achieves a peak measured PCE of 94.5%.