A great deal of interest is placed nowadays in the so called Internet of Things (IoT), it is said to be part of the society of the future where all devices are at the same time connected to the internet and among them. Nevertheless, must of the research devoted to this field has only been focused on the design of devices to operate with air as the surrounding medium. When the medium where the device is supposed to work is different than air, or when this medium has physical and chemical properties that change in time, there's a whole new set of constrains a device embedded in such a medium must meet so its adequate performance is guaranteed. To broaden the application spectrum of this technology, it is required to adequate the design of such devices to meet the requirements of the new medium, while still achieving the performance of the already existing devices. This master thesis studies the case of a RFID sensor embedded in a medium equivalent to concrete. A device adapted to the characteristics of the surrounding environment is designed, manufactured, tested and optimized in both a medium with properties equivalent to the ones of concrete and in concrete itself.