Ceramic RFID Tag for Omnidirectional Long-Range Communication

Radio frequency identification (RFID) is a wireless technology that allows contactless readout of data, encoded on time-modulated backscattering from a passive device. While this technology was already found beneficial in many retail applications, its further spread demands developing pathways to reading range extension and immunity to an interrogation direction. Here we demonstrate a new architecture, where a standard metallic RFID tag antenna is replaced by a ceramic resonator. The high permittivity of the structure allows encompassing of several cascaded resonances within a subwavelength volume and exploits the multi-channel operation of the communication link to shrink the footprint of the device. Spectral sharing between several mutually orthogonal dipolar resonances is designed to achieve an omnidirectional operation. As a result, a structure, encompassed in a 15 mm radius sphere, assessable from a 16 $\mathbf{m}$ distance is numerically demonstrated. By now, this is the best reading range in the category of omnidirectional RFID tags. Further efforts on footprint reduction can bring ceramic RFID architectures towards mm-scale layouts, making them beneficial in numerous applications, including the Internet of Small Things.