Design of an Ultra-low Power Wireless Temperature Sensor Based on Backscattering Mechanism

In this paper, we propose a passive wireless temperature sensor for long-term and long-range application. A novel architecture of the wireless temperature sensor is proposed based on backscattering mechanism of RFID technology for ultra-low power application. The temperature sensor adopts phase-locked loop-based architecture and can achieve the temperature-digital conversion in frequency domain without any external clock signal. The rectifier employs a gate-boosting scheme to improve the power conversion efficiency. The measurement results show that the proposed wireless temperature sensor obtains a high linearity with a resolution of 0.3 °C/LSB. The measured minimum power dissipation is 2.7 µW, resulting in a maximum operating distance of 34 m under 4 W radiation power.