Slotted circular microstrip patch antenna application in strain based structural health monitoring

In this paper, the effect of a rectangular slot on the sensitivity of circular microstrip patch antenna strain sensors is investigated. Theoretical studies, experimental tests, and Finite Element Analysis (FEA) show that circular microstrip patch antennas are capable to detect and measure strain. A slotted circular microstrip patch antenna could increase the sensitivity of the antenna sensor three-fold. In order to investigate the effect of slot in the patch antenna both FEA and experimental tests are considered. Antenna sensor is tested under 3-Point bend test and simulated using two established proprietary packages. The effect of aluminium and carbon fibre materials and direction of bending on sensitivity of the antenna sensor is also investigated. Based on the results obtained, the antenna sensor can be recommended for use in structural health monitoring for strain-based damage detection in aerospace structures.