Wireless temperature measurement system with RF transceiver and powerless sensor

In this study, wireless temperature measurement system is developed using SAW (Surface Acoustic Wave) device that is sensitive about temperature. We used principle that saw sensor resonant frequency is varied following temperature change. The RF reader designed and fabricated for find out resonant frequency of SAW sensor. High performance PLL and Down-converting method The RF reader has a characters high frequency resolution and high reception sensitivity. The wireless temperature measurement system operate about 3[m] distance and ±2[°C] temperature error. A wireless temperature measurement system can be utilized for power plant equipment such as a transformer that person is difficult to approach.