Surface Acoustic Waves (SAW) is a powerful technology enabling the design of innovative wireless passive sensors for temperature, strain or pressure measurements for instance. SAW technology exploits the piezoelectric properties of the sensors' quartz substrate. Wireless SAW sensors are powered by the energy of radio waves emitted by the associated transceiver unit when remotely interrogating the sensors in real-time. Advanced interrogation methods implemented in the embedded firmware of the

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... nsceiver compute the frequency changes in the sensor response into measurements. SAW technology has been used since more than 30 years for frequency filters, like in mobile phones with high-volume production, but its use for measurement is a breakthrough and the development from "proof of concept" to industry-standard-compliant systems was a challenge. This article describes key developments to overcome these challenges, highlights SAW sensors' features for industrial monitoring and provides examples of value-added applications.