Can you help me to choose a chip or technologi?

[SS.8]

Can you help me to choose a chip or technology. I need to read some passive tags on distance about 2 meters. Is it possible with the ST25R3916-DISCO and ISO15693 protocol? Which anntenna i should make? Which tags i should use? If no, can you give me advice which chip i should use and so one?

[Berenice BENVEGUDA]

​Hello,

Thanks a lot for this interesting question.

The benefit of ISO15693 standard is to reach reading distances about 1m or 1.5m with high power industrial readers, combining this performance with interoperability with smartphones.

Nevertheless to reach 2m reading distance or more, the UHF technology is more suitable and you can choose the ST25RU3993-EVAL for this purpose :

https://www.st.com/content/st_com/en/products/evaluation-tools/product-evaluation-tools/st25-nfc-rfid-eval-tools/st25-nfc-rfid-eval-boards/st25ru3993-eval.html

Hope this helps you in your choice,

Best Regards,

BB

[SS.8]

Hello, thank you. Can you help me again please?

[SS.8]

I see. So it is impossible to reach 1.5 m distance with this ST25R3916 or similar chip, right? May be with bigger antenna? UHF expensive and difficult technology

[SS.8]

ok, i'll try to explain more detail. I need to read passive tags about 1.5 square and about 0.5 m to height. May be it possible with big antenna(full square antenna?)

[SS.8]

Hello, so is it possible with big antenna or not?

[Ulysses HERNIOSUS]

Hi,

I guess Berenice is in her well-deserved vacation. I was chatting now with some antenna experts on this topic:

Of course everything is possible but it always depends on the effort and money you want to invest...

What will not work is that you take e.g. ST25R3916-DISCO board and connect a different antenna and it just works. One of the reasons is that it does not provide enough power to create a field large enough and sufficiently powerful and large enough to power the tags.

Roughly for an NFC antenna the diameter corresponds approximately to the achievable operating range. With ST25R3916 you can achieve a bit more range but not orders of magnitude more. Critical with your setup is also the required x and y dimension which when built with a single antenna will probably lead to tags not being read in the middle.

We don't have applications achieving such range so we cannot give you explicit recommendation and you need to experiment to see what can work and what cannot.

In general you need to consider:

1. Integrating a power amplifier to be able to create enough power
2. Working on a specialized antenna:
   1. Either integrating inner loops to see if you can address middle area with it or
   2. create an antenna array and use a multiplexer to drive these antennas time-multiplexed.

You can also look around to see what professional suppliers like FEIG offer, they have a selection of long range antennas and also reader modules with multiplexers.

Regards, Ulysses