A Concept of Pressure Sensor Based on Slotted Waveguide Antenna Array for Passive MMID Sensor Networks

The concept presented in this paper proposes to exploit the structure of a 3-D slotted waveguide antenna array (SWAA) to turn it into a completely passive millimeter-wave identification (MMID) pressure sensor. The pressure sensor is realized by ending the SWAA with a metallic membrane, where the variation of pressure causes a variation in the radar cross section (RCS). The concept is studied across the RCS measurement of the SWAA ended by a sliding short circuit to emulate the membrane deflection. Experimental results show that a sensitivity of 22.46 mm
²
/mm of short-circuit displacement is reached at 57.8 GHz. An estimated read range of 1.1 m is considered with an MMID reader compliant with the ETSI European power emission regulation.