An overview on Modulated Scattering Sensors and their applications

Abstract

Modulated scattering sensors are based on the scattering properties of small antennas. They operate similarly to radio frequency identifier RFIDs but they don't require a radio front-end, and with respect to RFIDs, which are characterized by a limited operative range, MST sensors can theoretically reach any distance up to kilometres. The information is carried on by modulating an impinging/interrogating electromagnetic wave by properly change the load impedance of the antenna sensor, with suitable resistive loads and electronic switches. MST sensors can also operate at microwave frequency bands thanks to the introduction of suitable MEMs switches able to operate up to 100 GHz, moreover they are simple, low invasive and very cheap. In this work the evolution and some recent advancements in the development and application of MST sensors at different engineering scenarios will be reported and commented.