MFRC522 NTAG213 range improvements

[jeremyst]

Hi,

My company is using MFRC522 to read the ID of Ultralight tags on a custom PCB for a consumer application.

However I have found a significant difference in range between different tags. MiFARE Ultralight NTAG213 only have ~2cm of range whilst an older MiFARE Ultralight tag (not certain of the type but suspect NTAG203) has ~5cm of range.

This was confirmed using a 'Arduino compatible' development board.

Is it to be expected for the NTAG213 to have a lower range? How could the range be improved? (we have already tuned the antenna to be resonant and 500ohms)

Thanks,

Jeremy

[Jorge_Gonzalez]

Hello Jeremy ST,

In general if the tags have a different antenna size (e.g. the antenna of your NTAG213 is smaller) then different reading distances are expected.

If you want to improve reading distance then I can suggest 2 options:

1) Tune the antenna to a lower target impedance, always respecting the MFRC522 maximum output power IDD(TVDD) = 100 mA).

2) If you have reached the max output power then you can use an RF Amplifier design as described in application note AN1425:

http://cache.nxp.com/documents/application_note/AN1425_AN166510.zip

Best Regards!

Jorge Gonzalez