Embedded microstrip patch antenna for structural health monitoring applications

In this paper, the gain and return loss of embedded antennas within concrete were investigated. It was shown that the antenna resonance can be made independent of the surrounding concrete medium by using a foam cover layer. Additionally, significant improvements in gain (up to 25 dB) were measured. Far field measurements taken on different days after the concrete pour showed gain increase of up to 7.5 dB as the concrete cured. This was attributed to the reduction in water content within the block.