Analysis and Design of a Concrete Embedded Antenna for Wireless Monitoring Applications

In this article, we describe an embedded circularly polarized patch antenna for the batteryless sensor monitoring of concrete structures. In particular, we focus our effort on designing a patch antenna that is able to work in concrete and has different dielectric properties without changing the input impedance to achieve an optimal power transfer. The antenna is designed and optimized by exploiting an analytical model that is suitably customized for the case at hand and a full-wave numerical analysis. The achieved results give physical insights into the antenna performance and explain its robustness against variations in the concrete. Experimental measurements fully confirm the model predictions. Although our work is focused on the particular application concerned with concrete health monitoring, the developed analysis can be extended in a conceptually easy fashion to other fields such as antenna design for biomedical and subsurface microwave imaging.