How can I design an NFC Antenna with custom geometry?

[DPing]

I have to design an NFC Antenna that has to stay on PCB whic shape is a circular sector.

I'm thinking to design an antenna that follows the profile of the PCB.

Is that a good idea? Do you have any other suggestions?

Thanks

[Travis Palmer · Accepted solution]

​Hello,

putting the antenna traces on the same PCB as the ST25R391x reader IC is possible. You can use the ST25R3911B-DISCO board as an example. The metal inside the Antenna will change your antenna parameter. This is quite difficult to calculate. For an rough estimation you can use the eDesignSuite - It will not be able to consider GND planes in the center of the antenna. https://my.st.com/analogsimulator/html/#/home

You should also have a look at the AN4974: "Antenna matching for ST25R3911B/ST25R391x devices" appnote.

br Travis