An Innovative Semicircular Spiral Antenna for On-Metal Passive RFID Applications

The special geometric layout of actual engineering project requires the tag to be placed in a special metal cavity, which severely blocks the propagation of the electromagnetic (EM) field from the reader to tag. To guarantee the effective communication between the reader and tag, an innovative semicircular spiral antenna that works on 13.56 MHz with an effective working distance up to 100 mm has been developed to realize noncontact synchronous transmission of power and data from the reader to tag. By using the finite element method, the key features of this innovative semicircular spiral antenna, and its design and optimization processes have been presented in detail.