This paper presents the characteristics of specifically designed tag (SDT) placed on an autoclaved aerated reinforced lightweight concrete to detect and inspect qualities of material products. The proposed SDT is a folded dipole antenna designed using the CST Microwave Studio simulation program. In this system, the SDT acts as a radio frequency identification (RFID) sensor. Simulated results show that the radius of the reinforced metal has important effects to SDT characteristics placed on material under tests.