I’d like to know what size the antenna has that comes with the 13.56MHz RFID module (RFR105A1M)? I read in the accompanying RDM880 document that the acceptable antenna sizes are:
155*166mm(special, required customized)
If the included antenna is not the largest size, where can I find instructions on how to build the largest size antenna that will work with this module? All under the assumption that larger antenna = larger range.