Compact Measurement Apparatus for 3D Spherical Read Range Characterization of Chipless RFID

In the literature, chipless RF identification (RFID) tags are mostly characterized at normal incidence, where the 3D spherical reading zone of chipless RFID tags has not been characterized. In this paper, compact measurement systems for the characterization of scatterers in 3D spherical read range are presented. Customized support structures are realized for the commercial multi-probe measurement system StarLab from MVG to construct the 3D spherical bistatic and monostatic measurement systems. A graphical user interface (GUI) is programmed to control the measurement systems and to perform postprocessing of the measurements. Owing to these measurement setups, 3D characterizations of three scattering objects are presented: an aluminum sphere, a nondepolarizing rectangular loop based chipless RFID tag, and a depolarization RF Elementary Particle (REP) chipless RFID tag. The measurement setups are capable to characterize any lightweight scatterer.