Calibration Method for an RF I-V Based HF RFID Impedance Measurement System

This paper presents a novel measurement system based on the radio frequency (RF) current-voltage (I-V) method of impedance measurements, capable of providing high sensitivity over a wide range of impedance. We use this system to characterize high frequency (HF) radio frequency identification (RFID) chips. A newly developed calibration method enables us to calibrate the system using three well-known calibration standards. Besides, we estimated the accuracy of our measurement system using another set of well-known reference standards. We achieved a high accuracy (1.5%) compared with related measurement systems, which are, in general, based on vector network analyzer (VNA) measurements (3.2%). In comparison with VNA-based systems, our proposed measurement system provides a low-cost, yet accurate method of measuring HF RFID chip impedances.