Tunning circuit for 25R200 and antenna

[Memer]

Hello I am trying to use the NFC Tuning Circuit to use this anteanna (https://www.te.com/en/product-L000641-01.html) to work with ST25R200 (https://www.st.com/en/nfc/st25r200.html).
Some of the parameters needed on the tool are not on the antenna datasheet. Can I still use the tool with other OK values or I need to find the real value of the parameters?
Any response is greatly apriciated, thank you for your attention.

[Travis Palmer · Accepted solution]

Hello Memer,

The datasheet does not reveal the self resonance frequency (important to estimate the parallel cap to tune the matching network at 13.56MHz) and the resistance at self resonance frequency (important to calculate the damping resistor / Q-Factor - could also be done with a scope once the reader is tuned and operating).

I would propose to request these two parameters from the manufacturer in order to be able to calculate the matching network.

Another solution is to measure the parameter according AN6065 using a VNA.

Please let us know, if you have additional questions.

BR Travis

[Memer]

Thank you very much!