MFRC522 antenna design problem

[mariooo]

I am not any kind of expert. Just want to get design working. I have a problem with an antenna for MFRC522 NFC chip.

I used a generator for NFC antennas. So my antenna has size 25x25mm and 3 turns.

Screenshot 2020-10-01 at 14.23.21.png

Then I used excel sheet and software provided by NXP for calculating antenna matching circuit.

Screenshot 2020-10-01 at 14.24.33.png

Schematics:
Values were adjusted to those given by calculator
Screenshot 2020-10-01 at 13.34.00.png

My PCB:
Screenshot 2020-10-01 at 13.31.46.png
Screenshot 2020-10-01 at 13.32.33.png

Right now I can’t read and write tag.
Signal from tag sniffed by oscilloscope shows some kind of communication.

I don’t have vector analyser for characterising antenna.
How to approach this problem?

[stephanie_m]

Hello,

As the device is not recommend for new design we only have available the information and the excel calculation , still for antenna design we recommend the use of some special equipment , you can check more details in the antenna design webinars we have available in the following page .

Hope this helps.

regards,

Estephania