AnsweredAssumed Answered

NFC Antenna Inductance

Question asked by Circuit Sense on Apr 8, 2018
Latest reply on Apr 16, 2018 by Kan_Li

When measuring the inductance and resistance of a rectangular antenna for PN53x using a VNA like miniVNA

at what frequency should the parameters be measured ? 


A) 1 MHz

B) 13.56 MHz.



AN11535 the document says measure it at 1 MHz.

AN1445 says measure it at 1 MHz.


Slide 21 of this presentation says - 

The antenna loop has to be connected to an impedance or network analyser at 13.56 MHz to measure the series equivalent components



If I look at the NFC Antenna tuning video on NXP site the parameters measured are at 13.56 MHz.





I would like to know why the discrepancy ?? and what is the correct method.