Need more details about Flexible sticker antenna usually supplied with ST25R3911B-DISCO

[PSaho]

Hi There,

We would like to know more details about the antenna specification of the flex sticker antenna which is supplied with ST25R3911B-DISCO reader boards.

Please let us know if we can interface the above antenna with ST25DV IC.

Image of the antenna attached.

[Berenice BENVEGUDA]

​Hello,

First of all, thanks for your interest in ST25 products !

The image you attached to the post is a ST25 tag ( IC + its antenna) and not an simple antenna.

so you cannot use it as an antenna to connect with ST25DV-I2C.

to interact with ST25DV-I2C, there is a ST25DV-DISCOVERY available  :

https://www.st.com/content/st_com/en/products/evaluation-tools/product-evaluation-tools/st25-nfc-rfid-eval-tools/st25-nfc-rfid-eval-boards/st25dv-discovery.html

or you can use the ST25R3911B-DISCO to read this supplied ST25 tag directly.

I hope this answers your questions,

Bets Regards,

BB

[PSaho]

Hello BB,

Thanks for your kind response.

We have already tried multiple readily available antennas with ST25DV-I2C but we achieved maximum reading distance using this flex antenna. So we want to use this flexible antenna design in one of our product with ST25DV-I2C. So we needed the antenna design, dimensions and specification. Kindly share us any available document about this flex sticker antenna.

Regards,

Preet

[Berenice BENVEGUDA · Accepted solution]

​Hello Preet,

The tag has been designed by an external  partner, so we have no specification documents to share with you.

You have to know that this tag has been designed with a tuning capacitance about 23 pF whereas the required tuning capacitance for ST25DV-I2C is more about 28.5 pF.

So it should not be optimum.

Have you already try following antenna for ST25DV-I2C ? :

  https://www.st.com/en/evaluation-tools/ant7-t-st25dv04k.html

or   https://www.st.com/content/st_com/en/products/evaluation-tools/product-evaluation-tools/st25-nfc-rfid-eval-tools/st25-nfc-rfid-antennas/ant-1-6-st25dv.html

Regards,

BB

[PSaho]

Hello BB,

Thanks for the information. We ordered one of these antenna and other we will try to acquire. We were actually looking for a smaller antenna with good reading distance because these PCB antenna will be difficult to fit inside our product design. We have tried one SMD coil type antenna (Pulse W3102) but that did not give us much long reading distance (We got 4CM with ST25R3911B-DISCO).

Anyway thanks a lot for your support !! If you find any small antenna compatible with ST25DV-I2C with which we can achieve good reading distance you can suggest us.

Regards,

Preet