Study Of Wireless Telemetering System Based On SAW Sensor

SAW sensors have overwhelming predominance to be applied in long-term and real-time telemetering under the closed, harsh and complex condition due to lots of advantages such as high sensitivity, small size, low power consumption and simple structure, especially the capability of being designed as passive wireless for detecting environmental parameters.In this paper, the principle of one-port SAW resonator sensor was introduced firstly, and the process of design and manufacture was briefly presented. Then the structure of SAW sensing telemetering system based on RF interrogatory technology was analyzed thoroughly, and the hardware and software were designed and fabricated. At the same time, according to the requirement of in-vivo temperature measurement, a SAW temperature sensing implant based on technology of wireless power supply and the corresponding telemetering system based on NI virtual instrument were designed. Finally, after the debugging of each functional unit, an integrated test had been taken to verify this system. Compared to the standard measurement device, the results show that in the range of 20℃-50℃, the temperature measurement accuracy of this system is about±0.1℃. Furthermore, animal experiment demonstrates that this system-has-accomplished the measurement of body temperature successfully, and the measuring distance reaches up to 1 m with 20 dBm (-4.3 mW/cm2) transmitting power supply.This study improves the further development of passive wireless telemetering system based on SAW technology, and it is hopeful to promote the application in biomedical measurement.