There has been some controversy going on this week about drug companies using RFID technology to combat drug conterfeiting. The controversy isn’t over combating drug conterfeiting, it’s the fact that people belive that this is just an excuse to track the drugs to one’s home. RFID doesn’t work like that.

RFID tags can be either active or passive. Active tags contain their own power source and are good for only as long as the power source is active. Passive RFID tags do not have their own power supply. They are powered by a current induced into their antenna during the incoming radio-frequency scan.

Because of the differences in the way they are powered passive RFID tags can only transmit a limited amount of data for a very limited range while active RFID tags can transmit much more data over a much larger range. Also due to the way they are powered there is a pretty large gap between the manufacturing costs and physical size of passive and active RFID tags.

The differences in range is something important to understand. When I’m saying that active RFID tags can transmit over a much larger range we are talking yards as opposed to inches. While there are active RFID tags that can transmit to a receiver miles away these are way too expensive to used in manufacturing supply chain logistics. Active RFID tags used in manufacturing have only the range to be located only within a building at most and usually only within an aisle.

Passive RFID tags have a short range of at most a couple of feet. Their advantages of being small and cheap (under 50¢ a piece and getting cheaper) make them very attractive for identifying individual pieces and makes up for their lack of range. These things can be made into paper labels and applied to packaging with little alterations to current packaging equipment. Still they are currently only readable from at most a few feet away.

The worry about tracking these passive RFID tags after leaving the store is unfounded. In order for this to happen you are going to have to have a tag reader in your house and car that monitors your doors. This reader would have to be able to send the data it receives back to a central monitoring site for this to be of any good to anyone.