Circular NFC Antenna Reference Design

[maustin_redant]

I'm looking for some reference designs for circular NFC antennas that I can import into my KiCAD (or EAGLE) PCB project.

This link appears to provide them, but it just provides a PDF document listing a range of different circular and rectangular designs, but not any details that I can utilise to actually import a design into my PCB.

https://www.st.com/content/ccc/resource/premium_content/document/group0/b7/d8/32/06/81/0c/42/34/Antenna_Design_Premium_Resource/files/ST25_D-tag_antenna_reference_design_matrix.pdf/jcr:content/translations/en.ST25_D-tag_antenna_reference_design_matrix.pdf

Does anyone know where I might find something suitable on the ST website?

Thanks and regards,

Mike

[JL. Lebon · Accepted solution]

Hello, 

For your design, you can refer to this application note: https://www.st.com/resource/en/application_note/an2972-how-to-design-an-antenna-for-dynamic-nfc-tags-stmicroelectronics.pdf
How to design a circular antenna is explained in this application note: in chapters 3.2 and 3.3 you can find formulas on how to calculate the right size/width for the right inductance.

You also have a reference circular antenna design in the X-NUCLEO-NFC07A1 board. The gerbers are available here: https://www.st.com/en/ecosystems/x-nucleo-nfc07a1.html#documentation

Best regards.