HF RFID Tag Chip Impedance Measurements

Abstract

This work provides the measurement data of 16 high-frequency (HF) radio frequency identification (RFID) transponder (tag) chips. In particular, the chip input impedance was characterized versus chip input voltage at 13.56 MHz. The measurement is based on the radio frequency current–voltage impedance measurement method and achieves, compared to previous work, higher measurement accuracy of better than 1.5%. Along with the measurement data, the work presents a detailed analysis of six specific proximity and vicinity HF RFID chips, including a tag performance analysis of their magnetic field strength, their resonance frequency, and their quality factor, considering a typical credit-card-sized tag antenna.