A novel passive SAW temperature sensor with anti-collision

In this paper, a novel surface acoustic wave (SAW) temperature sensor is proposed. Code division multiplexing technique and the cross-correlation time delay estimating algorithm is used to achieve sensing information of each sensor and provide anti-collision communication. Firstly, the time interval between the reply signals from the two sets of reflectors is acquired to work out the temperature variation by correlation time delay estimating algorithm and the technique of adaptive filtering. Then, the anti-collision is achieved with the code division technique. Lastly, the feasibility and validation of the new type of SAW temperature sensor are testified by simulated experiments. The main advantage of this new type of sensor is that it has good anti-collision capability; meanwhile, the size of it remain small.