dielectrics

The above video gives an idea of what places like Walmart would like to do with RFID, and this type of item-level tagging is what has been driving the market.  RFID has been in use long enough that this sort of thing ought to be available, but it’s not. Why? Let’s start with RFID: it works like a barcode.  You have a scanner that reads the barcode using lasers.  In order to read the barcode, you need a line of sight: the scanner has be able to “see” the light hitting the barcode. RFID is similar, except it’s using a frequency of electromagnetic wave different than the range of visible light.  This frequency doesn’t require “line of sight” because objects that are opaque in the visible frequencies will be transparent at the operational frequencies that RFID systems use.  This is because RFID tags use antennas to capture and modulate electromagnetic […]