I need to separate employees from a group as each proceeds through the gate. Is RFID the way to go?
RFID can probably do the job, but it would depend on what exactly you are trying to do, as well as some other factors. If you had 50 people moving through a doorway, 25 of whom should be employees, and you wanted to confirm that all 25 had showed up, you could issue RFID badges to your staff and place readers at the doorway. However, passive ultrahigh-frequency (UHF) tags hanging around the neck and close to the body can be a challenge to read since UHF energy is absorbed by water, of which the body is mostly composed. So if two workers were walking through at the same time, one tag might prevent the other from being read.
Generally speaking, I recommend that companies use battery-assisted UHF tags. These utilize a battery to essentially enhance the tag's output and ensure read reliability. Convergence Systems Ltd. offers a battery-assisted passive (BAP) ID card.
—Mark Roberti, Founder and Editor, RFID Journal