I am considering building an RFID reader system that can monitor runners times in a foot race. I have read that there are three different types of RFID systems. LF, HF, and UHF. Which one would be best for this application? Has anyone had success building an antenna that can read RFID tags from a distance of a meter or more?
EDIT: Active or Passive? My current thought is to use passive technology. I want to be able to get the tags for as cheap as possible and I don't want there to be a chance of the internal batteries failing.