Wireless RFID Chip Impedance Measurement by Using an Reader and a Statistically Analysis

Inhalt:
For the development of an RFID tag it is important to have a good knowledge of the input impedance of the RFID IC in order to design a matched antenna. A new approach for a wireless chip impedance measurement, that only requires an RFID reader and at least three similar tag antennas that have different impedances is presented. The antennas are connected to the IC and for each combination the minimum activation power and/or maximum distance is measured. From these results the chip impedance is calculated. Starting from the procedure with three antennas, the method is expanded to use more test antennas and a statistically technique.