Toward a Compact Wireless Surface Acoustic Wave Pirani Microsensor with Extended Range and Sensitivity

A wireless vacuum sensor based on the Pirani principle and Surface Acoustic Waves (SAW) has been designed, simulated and manufactured. The sensing unit is a heat conductivity gauge based on a passive SAW temperature sensor. The required heating energy is applied to the sensor by means of inductive coupling whereas the measurement signal is sent via a ceramic antenna. The sensor is a compact polymer cube containing all the units and operating completely wireless. Simulation was used to design and optimize the behavior of the sensor in vacuum and to predict the performances of the sensor. It was followed by the manufacturing and the assembly of a prototype. This communication presents the design, the simulation results and the manufacturing steps of the prototype.