RFID Read/Write or Reader Module H-field
andreahs
Posts: 1
Hi all,
I'm trying to estimate the strength of the H-field in the middle of the RFID Read/Write Module and the RFID Reader Module antennas.
Do you know the H-field strength for these modules?
Alternatively, do you know the antenna currents? And some parameters of the antenna design (how many turns, radius of coil etc)?
I'm interested only in a rough estimate, or even an order of magnitude estimate. If these parameters aren't known off-hand, how would you recommend that I estimate them?
Any suggestion, insight or reference is really appreciated!
Thank you,
Andrea
Comments
You might reach out to Joe Grand as he designed the reader for Parallax.
Hi Andrea!
I couldn't find any existing data on H-fields, but maybe this info can help with your testing:
The RFID Modules all use the EM4095 RFID Read/Write Front End IC (https://www.emmicroelectronic.com/product/rf-reader-ics/em4095).
The inductance of our original antenna design was measured at 470uH, but that may have changed over the last 18 years due to PCB manufacturing variances.
The antenna runs on all 4-layers of the PCB with the same trace width, so to calculate length measure the external shape and multiply.