Can Stacked, Tagged Gift Cards Be Read and Inventoried 300 Deep in a Cardboard Carton?

First, there are different types of RFID technology that you could use. Magellan Technology has developed high-frequency (HF) tags that employ phase-jitter modulation (PJM) to achieve remarkable read rates on closely packed items (see Raflatac Promotes Phase-Jitter for Pharma). So utilizing these types of tags would likely produce accurate reads of the items within the carton. However, the read distance would only be a foot or two.

You could also employ ultrahigh-frequency (UHF) tags, which might be preferable if you were tagging other items within a store. It is likely that the packaging's thickness would be sufficient to allow the tags to be read, but you would probably need to do some work to achieve 100 percent read reliability.

One option would be to use a tunnel reader, with antennas on all four sides of a box. By bombarding the tags with energy from all sides, and by receiving from all sides, you would increase the likelihood of reading all tags. Another option would be to rotate the box in some way, or use a handheld reader and aim it at all sides of the carton, in order to allow energy to reach all tags. Placing the tags in different locations on the packaging would improve the ability to read the tags, though this might not be an option.

You would not be able to read these tags from very far away, and the box would be required to be in the read field for a while. Additionally, you would not be able to read all tags if you were pushing the box through a portal.