Reflection and transmission of microwaves in reinforced concrete specimens irradiated by modified antipodal Vivaldi antenna

In this article, the reflection and transmission properties of reinforced concrete specimens irradiated by a modified, high‐gain, ultra‐wideband antipodal Vivaldi antenna (MAVA) are investigated numerically and experimentally. First, the influence of the interfaces between free space and concrete and a reinforced bar (rebar) cell embedded in concrete on the reflection property is investigated at frequency range from 0.65 to 3.5 GHz. Second, the transmission property of the reinforced concrete specimens is investigated at 2.45 GHz using a small resonant microstrip patch antenna embedded in concrete at the location of a rebar cell with different values of cell parameter. It is shown that the reflection from the free space–concrete interface of specimens with and without rebars provides the most critical effect on the reflection and transmission properties of the specimens. It is also shown that maximum transmission can be achieved when the patch antenna is located in the center of the rebar cell. The measured results are in good agreement with the numerical results. The results of this article can be used for nondestructive testing of reinforced concrete specimens and for wireless power transmission to sensors embedded in reinforced concrete.