A Crack Mouth Opening Displacement Gauge Based on Van-Atta UWB Cross-Pol Chipless Tag Technology

A limitation to the practical use of chipless tags is due to the short reading distance, the small number of bits to be used for identification and the stability of the response. For sensor tag a further limitation is the sensitivity. In this work we present a design method and a model of a chipless sensor tag for crack mouth opening displacement that allow to improve these limitations. The sensor tag has been realized and measured confirming the design characteristics. It, based on the spectral signature, has 6 spectral lines (‘bits’) for identification, 1 spectral line for the sensor with adjustable sensitivity. In the experimental measurements it resulted readable from a distance of around 40 cm, from a direction of ± 15° with respect to boresight and with a sensitivity of around 29MHz/mm.