M24LR-discovery RF range versus external 3V3

mneary · ‎2013-08-14

Posted on August 14, 2013 at 22:24

Hello all,

I have been trying the M24LR-discovery board. Without applying an external 3V3 supply to the board, the operational range appears to be only about 1.5cm (less than one inch). There is an antenna design guide in the technical literature that indicates that for the 20mmx40mm antenna, range should be 25cm (unless the graph is wrong and this should be millimeters, but that seems unlikely as the worst antenna would have a 1mm range which is unreasonable). I cannot find any indication in the technical literature that the range will be dependent on whether the dual port memory is providing power to the whole board through its energy harvesting output. If anyone can provide an answer to me regarding whether or not the range is dependent on the energy harvesting output load, it will be appreciated.

Thanks a lot,

Mark

#ant2 #m24lr-range-improve-power-tag #devkit-m24lr-a #devkit-m24lr-a #m24lr-discovery

Anais GALLIGANI · ‎2013-11-04

Posted on November 04, 2013 at 10:53

Hi ,

Exact, with the Feig reader DEVKIT-M24LR-A and this antenna, you can not attend to go to a longer harvesting distance.

ST Dynamic NFC/RFID support

View solution in original post

Anais GALLIGANI · ‎2013-08-21

Posted on August 21, 2013 at 11:49

Hi ,

In the technical literatures that you might have seen, 25 cm is done with the DEVKIT-M24LR-A with a higher power (1W), biggest antenna, compare to the RF transceiver in the M24LR-discovery (55 mW @ 3.3V)

Please see

http://www.st.com/web/catalog/tools/FM116/SC1444/PF250417

I hope this might help you,

Have a nice day,

All the best,

ST NFC/RFID Dynamic support

jonathan23 · ‎2013-10-11

Posted on October 11, 2013 at 17:19

Hi,

I'm using the discovery board with the same Feig RF reader from the dev kit and I can only seem to get the board to charge up at a range of around 1-2 cm.

I noticed that the data sheet says that the 25cm with the 40mm * 20mm antenna is the maximum read distance, rather than a charge distance. I can confirm that the tag can be read to around 25cm. Therefore, I was wondering whether 1.5cm all I can hope for to power the discovery board, or should I be able to power it over greater distances?

Thanks,

Jon

Anais GALLIGANI · ‎2013-11-04

Posted on November 04, 2013 at 10:53

Hi ,

Exact, with the Feig reader DEVKIT-M24LR-A and this antenna, you can not attend to go to a longer harvesting distance.

ST Dynamic NFC/RFID support